Highway Concrete Technology

Development and Testing, Volume III:

Field Evaluation of SHRP C-205 Test 

Sites (High-Performance Concrete)

PUBLICATION NO. FHWA-RD-02-084 MAY 2006

Research, Development, and Technology

Turner-Fairbank Highway Research Center

6300 Georgetown Pike

McLean, VA 22101-2296
Foreword 

This research study, sponsored by the Federal Highway Administration, summarizes the field 

performance of eight high-early-strength (HES) concrete patches between 1994 and 1998. The 

patches were constructed under the Strategic Highway Research Program (SHRP) between June 

1991 and July 1992 and were located in five States (Arkansas, Illinois, Nebraska, New York, and 

North Carolina) using existing State construction practices. The patches were constructed mainly 

with Type III cement, four different types of coarse aggregate, and three different types of fine 

aggregate. Similar types of air entraining admixtures, water reducers, and set accelerators were 

used at all except the North Carolina site. The patches were located in areas with varying 

environmental and traffic conditions. The performance criterion of interest was durability. 

Durability of the HES concrete was quantified over a period of 7 years using various indicators 

including compressive strength, static elastic modulus, rapid chloride permeability, and asphalt 

concrete (AC) impedance. The HES patches were also examined visually to locate any materialor durability-related distresses. This report discusses in detail the effects of climate and material 

properties on the HES concrete durability. 

Some of the results of interest include the effect of water reducer type, curing method, and 

aggregate type on long-term durability. The report also presents comparisons of the rapid chloride 

permeability and AC impedance test results and the rate of strength gain for the mixes evaluated. 

Overall, the HES patches performed well with no obvious signs of deterioration. However, the 

results were not conclusive because the performance-monitoring period was relatively short. 

There is a need for further research in the areas of long-term HES concrete mechanical properties 

and durability. 

Gary Henderson 

Director 

Office of Infrastructure 

 Research and Development

Notice 

This document is disseminated under the sponsorship of the U.S. Department of Transportation in 

the interest of information exchange. The U.S. Government assumes no liability for its contents 

or use thereof. This report does not constitute a standard, specification, or regulation. 

The U.S. Government does not endorse products or manufacturers. Trade and manufacturers’ 

names appear in this report only because they are considered essential to the object of the 

document. 

Quality Assurance Statement 

The Federal Highway Administration (FHWA) provides high-quality information to serve 

Government, industry, and the public in a manner that promotes public understanding. Standards 

and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its 

information. FHWA periodically reviews quality issues and adjusts its programs and processes to 

ensure continuous quality improvement. 
Technical Report Documentation Page 

 1. Report No. 2. Government Accession No. 3. Recipient's Catalog No. 

FHWA-RD-02-084 

 4. Title and Subtitle 5. Report Date 

 Highway Concrete Technology Development and Testing, Volume III: May 2006 

 Field Evaluation of SHRP C-205 Test Sites (High-Performance Concrete) 6. Performing Organization Code 

 8. Performing Organization Report No. 

 7. Author(s) 

Jagannath Mallela, Leslie Titus-Glover, H. Thomas Yu 

 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) 

 ERES Division of Applied Research 

Associates, Inc. 

 505 W. University Avenue 11. Contract or Grant No. 

 Champaign, IL 61820-3915 DTFH61-94-C-00009 

 13. Type of Report and Period Covered 

 12. Sponsoring Agency Name and Address Final Report 

 Office of Engineering and Highway Operations R&D 

 Federal Highway Administration 

 6300 Georgetown Pike 14. Sponsoring Agency Code 

 McLean, VA 22101-2296 

 15. Supplementary Notes 

FHWA Contracting Officer's Technical Representative: Monte Symons, P.E. 

 

 16. Abstract 

This research study, sponsored by the Federal Highway Administration, summarizes the field performance of eight high-early-strength (HES) 

concrete patches between 1994 and 1998. The patches were constructed under the Strategic Highway Research Program (SHRP) between June 

1991 and July 1992 and were located in 5 States (Arkansas, Illinois, Nebraska, New York, and North Carolina) using existing State construction 

practices. The patches were constructed mainly with Type III cement, four different types of coarse aggregate, and three different types of fine 

aggregate. Similar types of air entraining admixtures, water reducers, and set accelerators were used at all except the North Carolina site. The 

patches were located in areas with varying environmental and traffic conditions. The performance criterion of interest was durability. Durability of 

the HES concrete was quantified over a period of 7 years using various indicators including compressive strength, static elastic modulus, rapid 

chloride permeability, and asphalt concrete (AC) impedance. The HES patches were also examined visually to locate any material- or durabilityrelated distresses. This report discusses in detail the effects of climate and material properties on the HES concrete durability. 

Some of the results of interest include the effect of water reducer type, curing method, and aggregate type on long-term durability. The report also 

presents comparisons of the rapid chloride permeability and AC impedance test results and the rate of strength gain for the mixes evaluated. 

Overall, the HES patches performed well with no obvious signs of deterioration. However, the results were not conclusive because the performance 

monitoring period was relatively short. There is a need for further research in the areas of long-term HES concrete mechanical properties and 

durability. 

 17. Key Words 

Concrete pavement, durability, compressive strength, rapid chloride 

permeability test, AC impedance test, life cycle cost 

18. Distribution Statement 

No restrictions. This document is available to the public through the 

National Technical Information Service, Springfield, Virginia 22161.

 19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No of Pages 22. Price 

Unclassified Unclassified 69 

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized 
ii

SI* (MODERN METRIC) CONVERSION FACTORS 

APPROXIMATE CONVERSIONS TO SI UNITS

Symbol When You Know Multiply By To Find Symbol 

LENGTH 

in inches 25.4 millimeters mm 

ft feet 0.305 meters m 

yd yards 0.914 meters m 

mi miles 1.61 kilometers km 

AREA 

in2 square inches 645.2 square millimeters mm2

ft2 square feet 0.093 square meters m2

yd2 square yard 0.836 square meters m2

ac acres 0.405 hectares ha 

mi2 square miles 2.59 square kilometers km2

VOLUME 

fl oz fluid ounces 29.57 milliliters mL 

gal gallons 3.785 liters L 

ft3 cubic feet 0.028 cubic meters m3 

yd3 cubic yards 0.765 cubic meters m3 

NOTE: volumes greater than 1000 L shall be shown in m3

MASS 

oz ounces 28.35 grams g

lb pounds 0.454 kilograms kg

T short tons (2000 lb) 0.907 megagrams (or "metric ton") Mg (or "t") 

TEMPERATURE (exact degrees) o

F Fahrenheit 5 (F-32)/9 Celsius oC 

or (F-32)/1.8 

ILLUMINATION 

fc foot-candles 10.76 lux lx 

fl foot-Lamberts 3.426 candela/m2 cd/m2

FORCE and PRESSURE or STRESS 

lbf poundforce 4.45 newtons N 

lbf/in2 poundforce per square inch 6.89 kilopascals kPa 

APPROXIMATE CONVERSIONS FROM SI UNITS 

Symbol When You Know Multiply By To Find Symbol 

LENGTH

mm millimeters 0.039 inches in 

m meters 3.28 feet ft 

m meters 1.09 yards yd 

km kilometers 0.621 miles mi 

AREA mm2

 square millimeters 0.0016 square inches in2 

m2 square meters 10.764 square feet ft2 

m2 square meters 1.195 square yards yd2 

ha hectares 2.47 acres ac 

km2 square kilometers 0.386 square miles mi2 

VOLUME 

mL milliliters 0.034 fluid ounces fl oz 

L liters 0.264 gallons gal 

m3 cubic meters 35.314 cubic feet ft3 

m3 cubic meters 1.307 cubic yards yd3 

MASS 

g grams 0.035 ounces oz

kg kilograms 2.202 pounds lb

Mg (or "t") megagrams (or "metric ton") 1.103 short tons (2000 lb) T 

TEMPERATURE (exact degrees) o

C Celsius 1.8C+32 Fahrenheit oF 

ILLUMINATION 

lx lux 0.0929 foot-candles fc 

cd/m2 candela/m2 0.2919 foot-Lamberts fl

FORCE and PRESSURE or STRESS 

N newtons 0.225 poundforce lbf 

kPa kilopascals 0.145 poundforce per square inch lbf/in2

*SI is the symbol for th International System of Units. Appropriate rounding should be made to comply with Section 4 of ASTM E e 380. 

(Revised March 2003)
iii

TABLE OF CONTENTS 

CHAPTER 1. INTRODUCTION.................................................................................... 1 

BACKGROUND............................................................................................................. 2 

DESCRIPTION OF THE FIELD SECTIONS................................................................ 2

SUMMARY OF SECTION PROPERTIES—EXPERIMENTAL DESIGN.................. 7 

OBJECTIVE AND SCOPE OF THE STUDY................................................................ 9 

CHAPTER 2. VISUAL EXAMINATION OF SHRP C-205 SITES .......................... 11 

ARKANSAS.................................................................................................................. 11 

ILLINOIS ...................................................................................................................... 11 

NEBRASKA.................................................................................................................. 12 

NEW YORK ................................................................................................................. 12 

NORTH CAROLINA.................................................................................................... 12 

SUMMARY OF VISUAL EXAMINATION RESULTS............................................. 12 

CHAPTER 3. CONCRETE CORE TESTING............................................................ 15 

CORING PLAN ............................................................................................................ 15 

SIGNIFICANCE OF PERFORMANCE TESTS AND LABORATORY TEST 

PROTOCOLS................................................................................................................ 15 

DESCRIPTION OF METHODS USED FOR DATA ANALYSIS.............................. 18 

DATA ANALYSIS ....................................................................................................... 21 

CHAPTER 4. CONCLUSIONS AND RECOMMENDATIONS ............................... 45 

CONCLUSIONS ........................................................................................................... 45 

RECOMMENDATIONS............................................................................................... 45 

APPENDIX A. DISTRESS SURVEY MAPS............................................................... 47 

REFERENCES................................................................................................................ 63 
iv

LIST OF FIGURES 

Figure 1. Graph. Plot of compressive strength versus age for test site in Arkansas......... 23 

Figure 2. Graph. Plot of compressive strength versus age for test site in Illinois. ........... 23 

Figure 3. Graph. Plot of strength gain for the different experiments (aggregate type 

and water reducer type) in North Carolina. .............................................................. 24 

Figure 4. Graph. Plot of compressive strength versus age for test site in Nebraska......... 24 

Figure 5. Graph. Plot of compressive strength versus age for test site in New York 

(data available for insulated sections only)............................................................... 25 

Figure 6. Graph. Plot of cores’ compressive strength versus cylinders’ compressive 

strength...................................................................................................................... 27 

Figure 7. Graph. Plot of static elastic modulus versus age for the three aggregate 

types analyzed........................................................................................................... 28 

Figure 8. Graph. Plot of the measured and predicted EPCC from compressive strength 

for crushed granite. ................................................................................................... 29 

Figure 9. Graph. Plot of the measured and predicted EPCC from compressive strength 

for marine marl. ........................................................................................................ 30 

Figure 10. Graph. Plot of the measured and predicted EPCC from compressive strength 

for limestone. ............................................................................................................ 30 

Figure 11. Graph. Plot of charge passed versus concrete age for Arkansas. .................... 31 

Figure 12. Graph. Plot of charge passed versus concrete age for Illinois......................... 32 

Figure 13. Graph. Plot of charge passed versus concrete age for North Carolina............ 32 

Figure 14. Graph. Plot of charge passed versus concrete age for Nebraska..................... 33 

Figure 15. Graph. Plot of charge passed versus concrete age for New York. .................. 33 

Figure 16. Bar chart. Histogram showing RCPT results from the top and bottom 

sections of concrete cores (Illinois). ......................................................................... 36 

Figure 17. Bar chart. Histogram showing RCPT results from the top and bottom 

sections of concrete cores (North Carolina).............................................................. 36 

Figure 18. Bar chart. Histogram showing RCPT results from the top and bottom 

sections of concrete cores (Nebraska and New York).............................................. 37 

Figure 19. Graph. Plot of AC impedance versus age for concrete cores (Arkansas, 

limestone).................................................................................................................. 37 

Figure 20. Graph. Plot of AC impedance versus age for concrete cores (Illinois, 

limestone).................................................................................................................. 38 

Figure 21. Graph. Plot of AC impedance versus age for concrete cores (North 

Carolina, granite). ..................................................................................................... 38 

Figure 22. Graph. Plot of AC impedance versus age for concrete cores (Nebraska, 

limestone).................................................................................................................. 39 

Figure 23. Graph. Plot of AC impedance versus age for concrete cores (New York, 

limestone).................................................................................................................. 39 

Figure 24. Graph. RCPT versus AC impedance for the 100-Hz test................................ 40 

Figure 25. Graph. Distress map for patch NC-1 in North Carolina—1994...................... 48 

Figure 26. Graph. Distress map for patch NC-1 in North Carolina—1998...................... 48 

Figure 27. Graph. Distress map for patch NC-2 in North Carolina—1994...................... 49 

Figure 28. Graph. Distress map for patch NC-2 in North Carolina—1998...................... 49 

Figure 29. Graph. Distress map for patch AR-1 in Arkansas—1994. .............................. 50 
v

Figure 30. Graph. Distress map for patch AR-1 in Arkansas—1995. .............................. 50 

Figure 31. Graph. Distress map for patch AR-2 in Arkansas—1994. .............................. 51 

Figure 32. Graph. Distress map for patch AR-2 in Arkansas—1995. .............................. 51 

Figure 33. Graph. Distress map of section in New York—1994...................................... 52 

Figure 34. Graph. Distress map of section in New York—1998...................................... 52 

Figure 35. Graph. Distress maps for patches IL-1 and IL-2 in Illinois—1994................. 53 

Figure 36. Graph. Distress maps for patches IL-1 and IL-2 in Illinois—1995................. 54 

Figure 37. Graph. Distress maps for patches IL-1 and IL-2 in Illinois—1996................. 55 

Figure 38. Graph. Distress maps for patches IL-1 and IL-2 in Illinois—1997................. 56 

Figure 39. Graph. Distress maps for patches IL-1 and IL-2 in Illinois—1998................. 57 

Figure 40. Graph. Distress maps for patches NE-1 and NE-2 in Nebraska—1994.......... 58 

Figure 41. Graph. Distress maps for patches NE-1 and NE-2 in Nebraska—1995.......... 59 

Figure 42. Graph. Distress maps for patches NE-1 and NE-2 in Nebraska—1996.......... 60 

Figure 43. Graph. Distress maps for patches NE-1 and NE-2 in Nebraska—1997.......... 61 

Figure 44. Graph. Distress maps for patches NE-1 and NE-2 in Nebraska—1998.......... 62 
vi

LIST OF TABLES 

Table 1. Comparison of final laboratory and actual field concrete mix proportions 

for the New York site.................................................................................................. 3 

Table 2. Comparison of final laboratory and actual field concrete mix proportions 

for the Illinois site. ...................................................................................................... 5 

Table 3. Comparison of final laboratory and actual field concrete mix proportions 

for the Arkansas site.................................................................................................... 6 

Table 4. Comparison of final laboratory and actual field concrete mix proportions 

for the Nebraska site. .................................................................................................. 7 

Table 5. Summary of materials, site factors, and fresh concrete properties for the 

SHRP C-205 sites. ...................................................................................................... 8 

Table 6. Distress summary of SHRP C-205 section in North Carolina............................ 13 

Table 7. Summary of testing performed. .......................................................................... 16 

Table 8. Matrix of climate and material properties used in grouping the test sites 

for analysis................................................................................................................ 22 

Table 9. Summary of strength gain for combined compressive strength test data. .......... 26 

Table 10. RCPT Chloride permeability ratings. ............................................................... 31 

Table 11. Summary of chloride permeability for test sites evaluated............................... 34 

Table 12. RCPT and 100-Hz AC impedance test ratings. ................................................ 40 

Table 13. Summary of ANOVA results for the effect of curing method on strength....... 41 

Table 14. Summary of analysis of variance results for the effect of curing method 

on concrete permeability........................................................................................... 42 

Table 15. Summary of analysis of variance results for the effect of aggregate type 

on strength................................................................................................................. 42 

Table 16. Summary of analysis of variance results for the effect of aggregate type 

on concrete permeability........................................................................................... 43 

Table 17. Summary of analysis of variance results for evaluating specimen RCPT 

results. ....................................................................................................................... 43 
1

CHAPTER 1. INTRODUCTION 

BACKGROUND 

This research study, sponsored by the Federal Highway Administration (FHWA), 

summarizes the field performance of high-early-strength (HES) concrete patches 

constructed under Strategic Highway Research Program (SHRP) study C-205. (1) 

HES is designed to develop the strength needed for opening in 12 to 24 hours through: 

• The use of Type III cement. 

• High cement content. 

• Low water to cement (w/c) ratio. 

• Addition of nonchloride accelerator—calcium nitrite. 

A high-range water reducer (HRWR) is used in the mixture to maintain workability at a 

low w/c ratio. 

The test sections were constructed between June 1991 and July 1992 in five States that 

represent a wide variety of environmental and exposure conditions: Arkansas, Illinois, 

Nebraska, New York, and North Carolina. The basic configuration of the test sections 

consist of six 4.6-meter (m) (15-feet (ft)) full-depth patches made with HES. Three of the 

patches were insulated for more rapid strength gain, and three were uninsulated for 

normal curing. The test sections in Arkansas, Illinois, and Nebraska are of this basic 

configuration. In New York, only three insulated patches were placed. 

More extensive testing was conducted at the North Carolina site. The North Carolina 

section consists of 55 m (180 ft) of U.S. 17 on both driving lane and passing lane. The 

experimental factors for the North Carolina sections include the following: 

• Insulation—insulated and uninsulated. 

• Aggregate type—crushed gravel and marine marl. 

• HRWR type—naphthalene and melamine. 

The SHRP-C-205 report discusses aspects such as HES mixture proportioning, mixing 

and curing, laboratory experiments, and field installations.(1) Laboratory tests were 

conducted on both fresh or plastic and hardened concrete (both laboratory-cured and 

field-cored samples). These tests included the determination of fresh concrete properties 

such as slump, air content, and unit weight, as well as the estimation of the strength, 

modulus, shrinkage, and freeze-thaw durability for hardened concrete. 

SHRP C-205 showed that it is possible to produce HES concrete that will achieve its 

desired strength (35 megapascals (MPa) or 5000 pounds per square inch (psi) in 24 

hours) using conventional materials and equipment. However, more care is needed during 

batching, placing, and finishing than for normal concrete. 
2

The monitoring of the SHRP C-205 test sections conducted under this project showed 

that HES concrete patches can perform adequately in the field with no extraordinary 

signs of durability-related distresses under a wide range of climatic conditions. However, 

because the study only spanned 7 years into the life of the patches, additional monitoring 

is needed to evaluate the long-term durability of these materials. 

DESCRIPTION OF THE FIELD SECTIONS 

High-performance concrete patches constructed at the following sites were monitored as 

part of this study: 

1. I–88 eastbound (EB) near marker 88I-9406-3158 in Otsego County near 

Worcester, NY 

2. U.S. 17 just north of Williamson, NC 

3. I–57 about 16 kilometers (km) (10 miles (mi)) north of Effingham, IL 

4. I–40 less than 8 km (5 mi) west of Forrest City, AR 

5. U.S. 20 at mile marker 361 (Station 435) northwest of Norfolk, NE 

Brief descriptions of each patch, highlighting the various section details and other 

relevant site information, are presented below. Most of the information in this section 

was obtained from the original SHRP report.(1)

New York 

This installation was a full-depth patch constructed on Interstate 88, near the town of 

Worcester (about 82 km (50 mi) west of Albany). The patch is located in the eastbound 

passing lane near reference marker 88I-9406-3158. The patch was constructed on 

June 25, 1991. The original pavement was approximately 12 years old at the time the 

patch was built. 

The patch is approximately 18.3 m (60 ft) long, 3.7 m (12 ft) wide, and 225 millimeters 

(mm) (9 inches (in.)) thick, with doweled joints placed at 6.1-m (20-ft) intervals. Epoxycoated dowel bars were used, and the patch was provided with welded wire mesh 

reinforcement. The subbase consists of a 300-mm (12-in.) layer of sand, gravel, slag, and 

stone. The longitudinal joint with the adjacent lane was greased to act as a bond breaker. 

This patch was fully insulated to simulate properties of very-early-strength (VES) concrete. 

The climatic exposure of the pavement can be described as wet-freeze. The annual 

average daily traffic (AADT) was approximately 6,200 vehicles with about 20 percent 

trucks. 

Type III cement was used in constructing the patch, and the coarse aggregate was a 

crushed limestone. The admixtures used in the project included an HRWR, an airentraining admixture (AEA), and calcium nitrite. The materials were batched in different 

proportions in the laboratory prior to field installation, and the optimum mix design was 
3

selected. However, modifications had to be made in the field to the predetermined 

quantities to adjust for acceptable fresh concrete properties such as slump and air content. 

Table 1 contrasts the laboratory concrete mix proportions with the proportions batched 

onsite. The field mixture proportions satisfied the laboratory-specified values, with the 

exception of the amounts of water and HRWR added. The mix water in the laboratory 

seems higher than the field value. However, this is only an apparent discrepancy since the 

reported laboratory value was adjusted for free water in the aggregates and the calcium 

nitrate admixture, whereas the field value was not. The total amounts of water in both the 

laboratory and field were presumed to be the same if this discrepancy is accounted for. 

The discrepancy in the HRWR contents was noted in the original SHRP report.(1) In the 

field, the HRWR was reduced to decrease the total slump and air content in the mixture. 

Table 1. Comparison of final laboratory and actual field concrete mix proportions 

for the New York site. (1) 

Material Laboratory Mix 

Proportions 

Field Batch Proportions,1

Average (Range) 

Cement (Type III), lb/yd3

Water, lb/yd3

Coarse aggregate, lb/yd3

Fine aggregate, lb/yd3

HRWR, gal/100 lb of cement 

AEA, gal 

Calcium nitrite, gal/yd3

810

2762

1790

1040

1.33

0.38

6

816 (815–818)

190 (190–190)

1738 (1658–1776)

1090 (1077–1108)

1.1 (1.0–1.33)

0.38 (0.38–0.38)

6 (6–6) 1 Determined from the proportions reported from the three concrete delivery trucks. 

2

 Adjusted for free aggregate moisture and water in calcium nitrite. 

 1 pound (lb)/cubic yard (yd3

) = 0.593 kilogram (kg)/m3; 1 gallon (gal)/yd3 = 4.94 liter (L)/m3; 

gal/100lb = 0.083 L/kg 

North Carolina 

The experimental placement is on U.S. 17 over the Roanoke River, just north of 

Willamston. The pavement was constructed between July and August of 1991. 

The high-performance concrete pavement was approximately 55 m (180 ft) long and two 

lanes wide. It was unreinforced and jointed at 4.6-m (15-ft) intervals. However, dowel 

bars were placed only at the end of each day’s placement, with a maximum of 36.6 m 

(120 ft) between doweled sections. The inside lane was placed first, and its construction 

was controlled tightly, with emphasis on testing and materials. The lane was placed in 

three different sections, each 18.3 m (60 ft) long. The outside lane concrete was placed 

using typical North Carolina Department of Transportation (NCDOT) batching and 

placement rates, also in three 18.3-m-long (60-ft-long) sections. Here the emphasis was 

to study the impact of routine construction methods on variations in the product 

delivered. The minimum depth of the patches is 225 mm (9 in.). The pavement section 

was built on an asphalt base course. 
4

To mimic the strength development of VES concrete, some of the sections were insulated 

by first covering them with plastic sheets and subsequently placing 25-mm-thick (1-inchthick) rigid-foam building insulation on the slab. The insulation was removed after 6 

hours. The pavement can be described as being exposed to a mild marine environment. 

Type III cement and two coarse aggregate types—crushed granite (CG) and marine marl 

(MM)—were used in preparing the concrete mixture. The CG aggregate is very hard and 

tough, whereas the MM is a relatively porous shell limestone. In addition, two different 

HRWRs were used, one with a melamine base and the other with a naphthalene base. 

Apart from this, AEA and calcium nitrite were used as admixtures. Taking into account 

the curing methods employed (insulation versus no insulation) and the different 

admixtures and aggregates used, a total of eight unique combinations of test sections 

were built at the North Carolina site. All the mixtures contained the same nominal cement 

content and had approximately the same w/c ratio. The fine aggregates used in all the 

mixes were also the same. 

Illinois 

Two high-performance concrete experimental patches were constructed on Interstate 57, 

about 16 km (10 mi) north of Effingham. The patches were constructed in October 1991 

and are situated in the outside lane of the northbound highway, separated by a distance of 

305 m (1000 ft). The original pavement was approximately 24 years old when the patches 

were built. 

The patches are 13.7 m (45 ft) long, 3.7 m (12 ft) wide, and 250 mm (10 in.) thick, with 

doweled joints placed at 4.6-m (15-ft) intervals. Epoxy-coated dowel bars were used at 

all transverse joints. Both patches were constructed with welded wire fabric. The patches 

were placed on the existing granular subbase. One of the patches was fully insulated; the 

other was not. 

The pavement is situated in a wet-freeze environment. The average daily traffic (ADT) 

for this roadway is approximately 11,800 with approximately 22 percent trucks. Type III 

cement and limestone coarse aggregate were used in constructing the patch. The 

admixtures used in the project included an HRWR, an AEA, and calcium nitrite. The 

materials were batched in different proportions in the laboratory prior to field installation, 

and the optimum mix design was selected. However, modifications had to be made in the 

field to the predetermined quantities to adjust for acceptable fresh concrete properties 

such as slump and air content. 

Table 2 contrasts laboratory concrete mix proportions with proportions batched onsite. 

The onsite proportions were computed by taking averages of quantities used to prepare 

batches for each of the six trucks that delivered the concrete to the patches. The field 

mixture proportions satisfied the laboratory-specified values, with the exception of the 

water content added to the mix. It is assumed that this discrepancy can be attributed to the 

fact that the field water content reported does not include the water contributed from 
5

Table 2. Comparison of final laboratory and actual field concrete mix proportions 

for the Illinois site.(1) 

Material Laboratory Mix 

Proportions 

Field Batch Proportions1

Average (Range) 

Cement (Type III), lb/yd3

Water, lb/yd3

Coarse aggregate, lb/yd3

Fine aggregate, lb/yd3

HRWR, gal/100 lb of cement 

AEA, gal 

Calcium nitrite, gal/yd3

870.00

299.00

1685.00

1030.00

1.09

0.23

4.00

867 (865–869)

194 (183–198)

1743 (1732–1751)

934 (896–957)

1.25 (1.23–1.35)

0.23 (0.23–0.23)

4 (4–4) 1 Determined from the proportions reported from the six concrete delivery trucks. 

 1 lb/yd3

 = 0.593 kg/m3; 1 gal/yd3 = 4.94 L/m3; gal/100lb = 0.083 L/kg 

the calcium nitrite and the aggregates. Although the water content in the field could not 

be determined for this site due to lack of information about the exact amount of water 

contributed to the mixture by the aggregate, it was presumed in the original SHRP study 

that the laboratory and field values match approximately.(1)

Arkansas 

The Arkansas installation is on Interstate 40, less than 8 km (5 mi) west of Forrest City. 

There are two patches in the passing lane of the westbound traffic near mile marker 237. 

The patches are separated by a distance of about 152 m (500 ft) and were built in 

November 1991. The original pavement was approximately 25 years old when the 

patches were built and was built on cement-treated subgrade. 

The patches are 13.7 m (45 ft) long, 3.7 m (12 ft) wide, and 250 mm (10 in.) thick, with 

doweled transverse joints placed at 4.6 m (15 ft) intervals. One of the patches (the 

easternmost) was insulated with rigid foam insulation for about 3.5 hours after the 

concrete had set. 

The pavement is situated in a wet environment with potential for freeze-thaw cycling. 

The two-way AADT near the installation was approximately 19,890 vehicles with just 

over 47 percent trucks. 

Type III cement was used in constructing the patch, and the coarse aggregate was 

limestone. The admixtures used in the project included an HRWR, an AEA, and calcium 

nitrite. The materials were batched in the laboratory in accordance with the original HES 

mix design prior to field installation.(1) With the exception of a minor modification to the 

quantity of AEA, the rest of the original HES mix design was adopted. This adjustment 

was necessitated to achieve the target air content. Table 3 presents a comparison of the 

laboratory concrete mix proportions with the proportions batched onsite. The onsite 

proportions were computed by taking averages of the quantities used to prepare batches 

for each of the six trucks that delivered the concrete to the patches. 
6

Table 3. Comparison of final laboratory and actual field concrete mix proportions 

for the Arkansas site.(1) 

Material Laboratory Mix 

Proportions 

Field Batch Proportions1

Average (Range) 

Cement (Type III), lb/yd3

Water, lb/yd3

Coarse aggregate, lb/yd3

Fine aggregate, lb/yd3

HRWR, gal/100 lb of cement 

AEA, gal 

Calcium nitrite, gal/yd3

877.00

237.00

1693.00

1080.00

1.23

0.31

4.00

871 (866–881)

238 (236–239)

1702 (1680–1720)

1064 (1060–1080)

1.01 (0.97–1.14)

0.31 (0.31–0.32)

4.08 (4–4.29) 1 Determined from the proportions reported from the seven concrete delivery trucks. 

 1 lb/yd3

 = 0.593 kg/m3; 1 gal/yd3 = 4.94 L/m3; gal/100lb = 0.083 L/kg 

Based on the field batching, the w/c ratio was 0.27, and the standard deviation was 0.002 

between batches. The average entrained air content, slump, and unit weight were 4.6 

percent, 183 mm (7.2 in.), and 2318 kg/m3

 (143 lb/ft3), respectively. 

Nebraska 

Two high-performance concrete patches were built in Nebraska on the eastbound lane 

of U.S. Highway 20 between the towns of Osmond and Plainsview. The patches, 

constructed in July 1992, are the youngest of all the sections discussed in this report. The 

original concrete pavement was built in 1957 and consists of a 200-mm (4-in.) granular 

subbase resting on a silty clay subgrade. 

The patches are 14.64 m (48 ft) long, 3.35 m (11 ft) wide, and 200 mm (8 in.) thick. They 

were built end to end. One patch was insulated during the construction for roughly 5.5 

hours after the concrete had set. Transverse joints were sawed at 4.9-m (16-ft) intervals 

within each patch, and epoxy-coated dowel bars were placed at all transverse joints. 

The pavement is situated in a wet environment with a very high potential for freeze-thaw 

cycling. Approximately 1,500 vehicles per day with about 20 percent trucks constitute the 

traffic at the site. 

Type III cement was used in constructing the patch, and the coarse aggregate was 

limestone. The admixtures used in the project included an HRWR, an AEA, and calcium 

nitrite. The materials batched in the laboratory were, for the most part, in accordance with 

the original HES mix design, but the coarse aggregate and fine aggregate contents were 

reversed to suit local practice.(1) This adjustment was necessitated to reduce the 

probability of alkali-silica reactivity (ASR) prevalent in the area. 

Table 4 presents a comparison of the laboratory concrete mix proportions with the 

proportions batched onsite. The onsite proportions were computed by taking averages of 

quantities used to prepare batches for five of the six trucks that delivered the concrete to 
7

the patches. Data from one of the trucks was not used since the slab poured with the 

concrete mix from this truck was eventually replaced. It can be noted from the table that 

the field batching followed the laboratory specifications quite well. 

Table 4. Comparison of final laboratory and actual field concrete mix proportions 

for the Nebraska site.(1) 

Material Laboratory Mix 

Proportions 

Field Batch Proportions1

Average (Range) 

Cement (Type III), lb/yd3

Water, lb/yd3

Coarse aggregate, lb/yd3

Fine aggregate, lb/yd3

HRWR, gal/100 lb of cement 

AEA, gal 

Calcium nitrite, gal/yd3

873.00

228.00

1087.00

1710.00

1.23

0.34

4.00

876 (874–881)

214 (201–224)

1057 (1046–1065)

1747 (1745–1749)

1.44 (1.36–1.64)

0.33 (0.31–0.34)

4 (4–4) 1 Determined from the proportions reported from the five of the six delivery trucks. 

 1 lb/yd3

 = 0.593 kg/m3; 1 gal/yd3 = 4.94 L/m3; gal/100lb = 0.083 L/kg 

SUMMARY OF SECTION PROPERTIES—EXPERIMENTAL DESIGN 

Table 5 presents a summary of fresh concrete properties and important climatic indicators 

for each of the five experimental sites considered in this study. Mean values of the 

concrete w/c ratio, slump, air content, and unit weight are included in the table along with 

measures of variability of these properties within each site. The data presented in the 

table will be valuable in interpreting the long-term concrete performance data collected as 

part of this study and to draw important conclusions about the applicability of highperformance concrete as a patching material. 

The data on the average number of freeze-thaw cycles and the average freezing index 

were not collected at the sites under consideration in this study. They were determined 

from the Long-Term Pavement Performance (LTPP) climatic database from a weather 

station closest to the site under consideration. Also, the freeze-thaw cycles reported were 

based on air temperature and not pavement temperature. The actual pavement freezethaw cycles will be lower than this value, the exact magnitude being a function of several 

other site and pavement variables. Regardless, since the same parameter was used for all 

the sites, these data should give a relative indication of the climatic conditions at each of 

the sites. 
Table 5. Summary of materials, site factors, and fresh concrete properties for the SHRP C-205 

Climate Indicators Fresh Concrete P

Site 

Concrete Materials 

Used in Patch 

Construction 

Patch Curing 

Conditions LTPP Classification Average Air F-T1 Cycles Freezing Index, oF-days W/C Ratio Mean (SD2) Slump, in Mean (SD) Ai

M

New York Cement—Type III 

Coarse aggregate— crushed limestone 

Insulated Wet-freeze 113 584 0.34 (0.00)3 6.4 (1.6) 

North Carolina 

Cement—Type III Coarse aggregate— crushed granite; marine marl 

Insulated and uninsulated 

Wet-no freeze 71 45 0.33 (0.015) 4.7 (2.3) 

Illinois Cement—Type III 

Coarse aggregate— crushed limestone 

Insulated and uninsulated 

Wet-freeze 84 298 0.33 (0.01)1 8.9 (1.3) 

Arkansas Cement—Type III 

Coarse aggregate— crushed limestone 

Insulated and uninsulated 

Wet-no freeze 56 63 0.27 (0.00) 4.6 (1.4) 

Nebraska Cement—Type III 

Coarse aggregate— crushed limestone 

Insulated and uninsulated 

Wet-freeze 108 581 0.24 (0.01) 4.0 (1.9) 

1 F-T stands for air freeze-thaw cycles. 2 SD stands for standard deviation. 3 The mean w/c ratio reported is based on laboratory mix proportioning. The standard deviation is based on field batching data. 

 1 lb/ft3 = 16.02 kg/m3; 0 oC = 32 oF

8 
9

Based on the freeze-thaw cycle information presented in table 5, the Nebraska and New 

York test pavements are in the harshest cold-weather climate, followed by Illinois, North 

Carolina, and Arkansas. The North Carolina section uses different coarse aggregates than 

the others. The mix proportions are relatively uniform (not all mix information is 

presented in the table), except for some variation in the w/c ratio. The factorial presented 

in the table forms a good basis for reasonable comparison of the durability of highperformance concrete. 

OBJECTIVE AND SCOPE OF THE STUDY 

The objective of this study was to perform long-term performance monitoring to verify 

the effectiveness of high-performance concrete patches constructed in the previously 

referenced SHRP study. The emphasis during this monitoring effort was on determining 

the durability and integrity of the concrete over time. The following work items were 

undertaken to realize the objective of the study: 

• Collection of important site information such as weather conditions, traffic, use of 

deicers, and maintenance history of the pavement sections. 

• Visual inspection using standard SHRP distress identification procedures to detect 

durability problems such as joint spalling and cracking. 

• Obtaining photograph and video logs of each patch and the sections within each 

patch to record the progression of distress. 

• Obtaining and testing cores for compressive strength, elastic modulus, rapid 

chloride permeability, and asphalt concrete (AC) impedance. 

Visual inspections of the patches were to be performed once every year for a period of 5 

years beginning in 1994. Cores were obtained from the field in alternate years instead of 

every year, as was intended in the original project plan. 

11

CHAPTER 2. VISUAL EXAMINATION OF SHRP C-205 SITES 

Visual examination of the HES concrete patches was conducted each year between 1994 

and 1998, usually between the months of August and November. The survey teams 

consisted of experienced personnel, and care was taken to maintain uniformity in the data 

collection, as much as possible, over the entire performance monitoring period. The main 

data items of interest during the visual examination process included recording the 

progression of pavement distress within each patch, with special focus on materialsrelated distresses. The distresses were recorded through a variety of means, including 

mapping distresses, recording any changes in condition, and taking photos and videos of 

the section. In addition to monitoring the condition of concrete, for the North Carolina 

section it was also meaningful to collect and analyze pavement performance data such as 

faulting, transverse cracking, and joint spalling. At each site, the respective State DOT 

provided necessary traffic control to perform the distress surveys. 

Appendix A provides detailed maps showing the locations and magnitudes of the various 

pavement distresses as they developed during the performance period. Major findings 

from the visual surveys of each site are summarized below. 

ARKANSAS 

The HES patches (insulated and uninsulated) in Arkansas could be surveyed only in 1994 

and 1995. The patches were overlaid shortly after the 1995 survey as part of a major 

rehabilitation project on I–40. Each patch consisted of three pavement slabs 4.6 m (15 ft) 

long. Both patches exhibited minor scaling and map cracking in 1994. However, their 

condition did not vary significantly between the two survey dates. The joint sealant was 

in good condition on all sections, with no evidence of durability-related distresses. 

ILLINOIS 

The Illinois sections exhibit some map cracking. The level of cracking did not change 

substantially over the monitoring period, although some progression of map cracking was 

noted over the years. One plausible cause for this distress is the potential use of deicing 

salts on these patches. Subjectively, at least, the sections generally seemed more 

deteriorated in 1998 than in 1994 (perhaps the impression is due to more scaling). 

However, as noted earlier, these changes were difficult to quantify. Figures 35 through 39 

in appendix A show that both Illinois sections had some transverse cracking. The 

structural crack in the IL-2 section existed since 1994, and no significant changes in 

progression or deterioration of the crack occurred over the monitoring period. Other 

cracks are a result of the interconnecting of map cracks. A minor progression of these 

cracks occurred over the monitoring period, but none appeared to have progressed to a 

working, structural crack. 
12

NEBRASKA 

The Nebraska sections have a few transverse cracks, which have existed since 1994 (see 

figures 40 through 44 in appendix A). A modest increase in map cracking was noticed in 

1998. The map cracking occurred mostly along the joints and cracks and around the 

cores. The pattern cracking appeared characteristic of ASR, which is known to occur in 

the area. It is interesting to note, however, that map cracking appeared to be a problem 

only on the repair slabs (not just the SHRP repairs, but also other repairs in the area). The 

original concrete, placed in 1957, did not exhibit any signs of map cracking. 

NEW YORK 

The one experimental patch in New York remained in excellent condition with no signs 

of map cracking or scaling over the entire monitoring period. The scaling and map 

cracking prevalent in patches located at other sites did not affect this patch. It was 

reported in the original SHRP study that deicing salts were not used on this section 

between 1991 and 1993.(1) 

NORTH CAROLINA 

The North Carolina section is in excellent condition with no signs of map cracking or 

scaling. The concrete condition did not change over the monitoring period. The North 

Carolina patch is relatively long compared to the other patches, so monitoring the 

pavement performance is more meaningful. The pavement performance data from the 

North Carolina section are summarized in table 6. The transverse cracks present at the 

time of construction (due to delay in sawing joints) progressed over time from low to 

high severity in some locations. The section also exhibits some joint spalling and 

faulting. However, the levels of these distresses remained relatively low and their 

condition remained virtually unchanged over the entire performance monitoring period. 

SUMMARY OF VISUAL EXAMINATION RESULTS 

In general, the test sections did not show any significant changes in condition over the 

monitoring period, especially those in the warmer climates. The sections in freezing 

climates—the Illinois and Nebraska sections—showed some amount of map cracking and 

scaling. The severity of map cracking at these two sites increased slightly over the 

monitoring period, but not significantly enough to report as a different level of severity. 

Quantifying changes in severity for such distress proved difficult. The sites cannot be 

mapped accurately enough over the years to note minor changes that occur from year to 

year, and the photos do not show enough detail to be useful for this purpose. 
Table 6. Distress summary of SHRP C-205 section in North Carolina. 

Station Transverse Cracking Joint Spalling Faulting (

Number 1994 1995 1996 1997 1998 1994 1995 1996 1997 1998 1994 1995 1996 

0+15 L L L L -0.01 -0.03 0.00+30 L1 M1 M1 M1 M1 -0.032 0.002 0.00+45 L L L L L 0.04 0.05 0.00+60 L L L L L 0.00 0.00 -0.00+75 L L L L L 0.10 0.10 0.0+90 L L L L L 0.10 0.1+05 L1 M1 M1 M1 M1 L L L L 0.072 0.062 0.01+20 H H H H H Patch Joint Pat1+35 L L L L -0.01 0.00 0.01+50 M1 M1 M1 M1 M1 L L L L 0.062 0.072 0.11+65 0.07 0.08 0.0Percent/Average 31% 54% 54% 54% 54% 0.03 0.04 0.0

 1 Joint not sawed. 

2 Faulting of the crack.  1 inch = 25.4 mm L = Low M = Medium H = High 

13 

15

CHAPTER 3. CONCRETE CORE TESTING 

CORING PLAN 

In conjunction with the visual surveys conducted on the various sites, cores were 

obtained from within each test patch on a regular basis to evaluate the durability of the 

concrete materials. As noted earlier, the original project plan called for obtaining the 

concrete cores in each of the 5 years during which performance was monitored. However, 

to protect the structural integrity of the patches, and to preserve their condition, the coring 

plan was revised to taking cores only in alternate years. Therefore, cores were obtained 

only in 1994, 1996, and 1998 from most of the patches with the exception of the patch 

located in Arkansas. From this section, only two sets of cores could be obtained, one in 

1994 and the other in 1995, just before the pavement was overlaid. 

The cores were subjected to tests for compressive strength, modulus of elasticity, rapid 

chloride permeability, and AC impedance. Wherever possible, companion cores were 

obtained from the patches so that replicate testing could be performed for each test type. 

Table 7 summarizes the types of tests performed at each location, along with the year in 

which the tests were performed. (For brevity, the frequency and types of AC impedance 

testing performed are not shown in the table.) Many AC impedance tests were carried out 

in this study, using numerous combinations of test parameters. Further discussion of AC 

impedance testing is provided later in the report. 

The gaps in table 7 indicate instances when it was not possible to perform some of the 

testing. Furthermore, as noted in the table, each test patch in North Carolina was treated 

separately, and coring was done accordingly. Recall that multiple patches were 

constructed in North Carolina to determine the effects of different kinds of coarse 

aggregates and water reducers on the performance of concrete. Naphthalene (N) and 

melamine (M) water reducers were used along with crushed granite (G) and marine marl 

(MM) to set up the four experiments: NM, NG, MM, and MG. 

Prior to the origination of this contract, cores were obtained at 28 days and 6, 12, and 18 

months for comparison with cylinder strengths; their corresponding test results were 

documented in SHRP C-364. These data were also used in the analysis presented in this 

report. 

SIGNIFICANCE OF PERFORMANCE TESTS AND LABORATORY TEST 

PROTOCOLS 

As noted earlier, four types of laboratory testing were performed on the cores retrieved 

from the field sites. A brief description of the significance of each test in relation to the 

main objective of this study is presented below. The protocols that were followed to 

estimate the respective property values are also presented. 
Table 7. Summary of testing performed. 

Insulated Sections Uninsulated Secti

Compressive 

Strength 

Modulus of 

Elasticity RCPT Compressive Strength Modulus of Elasticity 

Location 1995 1997 1999 1995 1997 1999 1995 1997 1999 1995 1997 1999 1995 1997 19

New York X X X — X X X X X — — — — — — North Carolina NM NG MG MM 

X X X X 

X X X X

X X X X

—

X X X X

X X X

X X 

X X 

X X 

X X X X

X X X X

X X X X

—

X X X X

X X X

Illinois X X X — X X X X X X X X — X X Arkansas1 X X — X — X X — X X — — X — Nebraska X X X — X X X X X X X X — X X 

1 The cores designated as being tested in 1997 were actually obtained in 1995. This was accounted for in the data analysis.

“X” indicates test was performed; “—” indicates test was not performed. Gaps in text indicate instances when it was not possible to 

16 
17 

Compressive Strength and Elastic Modulus Testing 

In this study, the compressive strength and elastic modulus of concrete were used as 

surrogate indicators of material durability. Sound concrete with no materials-related 

problems is expected to gain strength and, to a lesser degree, modulus over time because 

of the continuing hydration process. The onset of any materials durability-related distress 

such as durability- (D-) cracking or ASR leads to the deterioration of concrete and results 

in the development of cracks in the cement paste and the aggregates. This causes a drop 

in the compressive strength and elastic modulus values. Therefore, by periodically 

monitoring the rate of strength and modulus gain (or drop), any durability-related 

problems can be detected. 

All of the compressive strength and elastic modulus tests were conducted after removing 

the top and bottom portions of the 100-mm-diameter (4-inch-diameter) cores, to form 

200-mm-long (8-inch-long) specimens. The ends were capped with a sulfur-based 

capping compound and tested to failure in compression in accordance with ASTM C 39 

for compressive strength and ASTM C 469 for elastic modulus. To represent their 

condition in the pavement more accurately, the cores were not soaked before testing. 

Rapid Chloride Permeability Testing 

The rapid chloride permeability test (RCPT) indicates the ability of the concrete to resist 

the penetration of chloride ions. Chloride ions may enter into the concrete from three 

major sources: set accelerating admixtures, deicing salts, and seawater and salt spray.(2) 

Although the ingress of these ions into concrete is primarily detrimental to the 

performance of the embedded steel, it can also produce durability problems in concrete 

such as salt scaling and map cracking. The test measures the amount of charge passed 

when a 60-volt DC electrical potential is placed across a concrete specimen for a 6-hour 

period. The greater the charge, the lower is the resistance of the concrete to chloride ion 

ingress, and therefore the greater the potential for materials-related problems. Therefore, 

the RCPT values over time can give an indication of the durability of concrete. 

The rapid chloride permeability tests were carried out on 100-mm-diameter (4-inchdiameter) specimens cut from the area between 12.5 and 62.5 mm (0.5 and 2.5 in.) from 

the top of the core, and from 12.5 to 62.5 mm (0.5 to 2.5 in.) from the bottom of the core, 

where applicable. Note that the bottoms of the cores have only been tested since 1997. 

The outside of the specimens was coated in epoxy, vacuum-saturated, and tested 

according to ASTM C 1202. 

AC Impedance Testing 

AC impedance testing was considered in the original SHRP study as a reasonable 

alternative to the RCPT for more rapid determination of concrete permeability. The goal 

was to explore a faster method that could be more versatile and portable.(1) The AC 

impedance test values have an inverse relationship to the RCPT values. 
18 

In the original SHRP study, the AC impedance testing was conducted using a Kohlrausch 

bridge instrument. The Kohlrausch bridge uses a 1000-Hz AC frequency. The electrical 

connection between the Kohlrausch bridge terminals and the concrete specimens was 

ensured using potassium agar gel. The impedance measurement was measured at five 

random points on each specimen. In the present study, a slightly different test setup used 

a programmable potentiostat in place of the Kohlrausch bridge. Other setup variables 

such as the frequency of the current and the electrical coupling between the potentiostat 

and the concrete specimen were also varied in an effort to establish a reasonable 

correlation with the RCPT measurements. Based on this experimentation, it was decided 

that the impedance values obtained at a frequency of 100 Hz AC using a Nilsson soil 

resistance meter in two-pin mode provided the best correlation with the RCPT 

measurements. These values are reported in this study. 

DESCRIPTION OF METHODS USED FOR DATA ANALYSIS 

The results from the various tests conducted are analyzed and presented in this section. In 

order to make the data more meaningful and to draw broad-based conclusions, the 

concrete core and cylinder test data from report SHRP-C-364 were merged with the 

database compiled from this study.(1) 

A major task in this study was to conduct field studies to investigate how HES concrete 

mix properties and field conditions influence durability and, hence, performance. A 

measure of durability was obtained by monitoring the following properties: 

• Concrete compressive strength (ASTM C 39). 

• Concrete static modulus of elasticity (ASTM C 469). 

• Electrical indication of concrete’s ability to resist chloride ion penetration through 

the use of RCPT (ASTM C1202). 

• AC impedance test at 100 and 1000 Hz (SHRP-C-364). 

A list of the durability indicator data available and used for investigation and analysis has 

already been presented in table 7. The first step in assessing the durability of HES 

concrete was to conduct a comprehensive bivariate analysis. The bivariate analysis 

consisted of plots of the various durability indicator variables with concrete age. These 

plots were used for observing trends of the durability indicator variables (dependent 

variable) over the performance monitoring period, which was approximately 

7 to 9 years for the sites evaluated. Bivariate statistics measure the degree of dependence 

between two variables (dependent and independent). They also show the trends and 

changes in the value of the dependent variable as the level of the independent variable is 

varied. For this study, the dependent variable was a durability indicator variable and the 

independent variables were the climate, construction, or materials-related variables or 

cluster of variables that could influence the concrete’s long-term durability. 

Results of the bivariate analysis were presented in the form of plots of the durability 

indicator variables against age for the different levels of the independent variables being 

evaluated. Simple statistical regression curves, trend lines, and correlation coefficients 
19 

were also developed, where necessary. The plots visually show the effect of the 

independent variables under investigation on the durability indicators. They were used to 

determine if the trends observed were reasonable and as expected from mechanistic 

analysis, engineering judgment, and past empirical analyses. However, because bivariate 

plots present the effects of only a single independent variable on the durability indicator, 

their effect on the durability indicator variable can be confounded by the effects of other 

independent variables not considered. This could lead to contradictory and misleading 

results. Observations from bivariate plots are therefore preliminary in nature and cannot 

be conclusive.(3) 

More sophisticated statistical tools such as analysis of variance (ANOVA) were also used 

to investigate the effect of the independent variables on durability. ANOVA determines 

whether differences in observed trends were statistically significant by determining the 

significance of each independent variable included in a linear regression model used to 

predict the given durability indicator. The linear regression models used for ANOVA are 

designed based on the hypothesis to be tested (e.g., the significance of a given 

independent variable). 

ANOVA models are versatile statistical tools for studying the relationship between a 

dependent variable (durability indicator variable) and one or more independent variables 

(e.g., climate). They do not require making assumptions about the nature of the statistical 

relationship, nor do they require that the independent variables be quantitative. ANOVA 

models are generally used for applications where the effects of one or more independent 

variables on the dependent variable are of interest. Independent variables in the models 

for ANOVA are mostly called factors or treatments. For example, for this study, the 

independent variable (aggregate type) had three factors, levels, or treatments (limestone, 

marine marl, and crushed granite). The basic ANOVA procedures used in this study for 

determining the effects of several factors on the dependent variables are summarized as 

follows(3): 

1. Determine all independent variables to be analyzed and transform the continuous 

independent variables into classification variables. 

2. Develop ANOVA models for predicting each durability indicator variable to be 

analyzed. The models must be based on a specific experimental design to 

determine the effect of a specific group of independent variables on the durability 

indicator. 

3. Perform ANOVA; using the models developed, test the hypotheses (the effect of 

curing method on durability, the effect of aggregate type on durability); and then 

determine if there is a significant difference in RCPT results from the top and 

bottom portions of a given core specimen. 

The procedure outlined is simple and suits the purposes of most simple analysis of 

variance. Key elements of the ANOVA procedure are further explained in the following 

sections. 
20 

ANOVA Models 

ANOVA models are basic, type I statistical models. They are concerned, like regression 

models, with the statistical relation between one or more independent variables and a 

dependent variable. Like regression models, ANOVA models are appropriate for both 

observational data and data based on formal experiments. Further, like the usual 

regression models, the dependent variable for ANOVA models is a quantitative variable. 

However, they differ from ordinary regression models in two key respects. First, the 

independent variables in the ANOVA model can be qualitative (e.g., aggregate type). 

Second, if the independent variables are quantitative, no assumption is made in the 

ANOVA models about the nature of the statistical relation between them.(3) 

Hypothesis Testing 

The goal of ANOVA is to compare means of the response variable (durability indicator) 

for various combinations of the classification variables (e.g., aggregate type and curing 

method). The effect and significance of the variables on performance can be confirmed or 

verified by comparing the level of significance of the variables to a predetermined level 

of significance, called p-value. ANOVA determines if there is a statistical difference in 

the mean values of the distress for the different classes of the independent variables in the 

model. The mean level of the distress for the different regression model classes gives an 

indication of whether the independent variable has a positive or negative effect on the 

distress. The following example illustrates the ANOVA technique. 

Treatment or factor (aggregate type): limestone 

 granite 

 Durability indicator (compressive strength): class (limestone) = μLS

 class (granite) = μGR

The significance of the effect of aggregate type on the given durability indicator is 

determined by the following test of hypothesis: 

Null hypothesis, Ho: μLS = μGR

Alternative hypothesis, HA: μLS ≠ μGR

Based on a significance level (p-value) of 5 percent (0.05), a p-value of less than 0.05 

rejects the null hypothesis, whereas a result greater than 0.05 confirms the null 

hypothesis. A comparison of the magnitude of the means determines the nature of the 

effect of the independent variable (in this case, aggregate type) on the durability 

indicator. 
21 

DATA ANALYSIS 

This section presents the results of both the bivariate analysis and a more detailed 

analysis of variance used in the investigation of the influence of climate and concrete mix 

properties on durability. 

Experimental Design 

For both the bivariate analysis and ANOVA, the effects of climate, construction, and mix 

properties on durability were investigated by grouping the data according to climate and 

mix properties. This was because relatively few data were available, as shown in table 7. 

To keep the individual evaluation data sets to a minimum size, engineering judgment was 

used to divide the data intelligently. Each of these divisions was specific to the durability 

indicator being investigated and is described in greater detail in later sections of this 

chapter. 

Climatic region was defined using the mean annual precipitation, mean annual air freezethaw cycles, and the mean annual freezing index of the sites; mix properties were defined 

using the aggregate type. Table 8 presents an example of the matrix of site and material 

properties used in grouping the test sites for analysis. 

Bivariate Analysis—Compressive Strength 

Figures 1 through 5 show the strength development history for the five sites analyzed. 

The plots show the effects of curing condition, specimen type (cylinder or core), strength 

at key ages, and site or climate. The specimen type describes whether the test data came 

from cores obtained from the concrete slabs or came from cylinders cast in foam boards 

using concrete samples obtained during slab placement. 

The data presented in figures 1 through 5 show no consistent trend in compressive 

strength in either insulated or uninsulated sections. However, the compressive strengths 

from cylinders (insulated or uninsulated) were generally higher than those from cores. 

The comparison of core and cylinder compressive strength was limited to data 

representing the age range from 28 days to 18 months because there were no data for 

cores outside this age range. For North Carolina, compressive strength was plotted 

according to aggregate type and water reducer types to determine their effect on strength 

gain, as shown in figure 3. 
22 

Table 8. Matrix of climate and material properties 

used in grouping the test sites for analysis. 

Precipitation 

(Wet > 20 in./yr) 

Temperature 

(Freeze Index) 

Freeze-Thaw 

Cycles Aggregate Type Sites 

Limestone Illinois 

< 100 Crushed granite — 

Marine marl — 

Limestone Nebraska, New York 

Crushed granite — 

Freeze 

>100 

Marine marl — 

Limestone Arkansas 

< 100 Crushed granite North Carolina 

Marine marl North Carolina 

Limestone — 

Crushed granite — 

Wet 

No freeze 

>100 

Marine marl — 

Limestone Illinois 

< 100 Crushed granite — 

Marine marl — 

Limestone Nebraska, New York 

Crushed granite — 

Freeze 

>100 

Marine marl — 

Limestone Arkansas 

< 100 Crushed granite North Carolina 

Marine marl North Carolina 

Limestone — 

Crushed granite — 

Dry 

No freeze 

>100 

Marine marl — 

1 inch = 25.4 mm; 0 oC = 32 oF 

Freeze Index: 

Freeze > 277 o

C degree-days 

No freeze < 277 o

C degree-days

The number of degree-days is the sum of the total number of degrees below freezing on each day when the 

average daily temperature is below freezing. For instance, if the average daily temperature is below 

freezing for 90 days per year, and the number of degrees Celsius below freezing is 2 per day, then the 

number of degree-days is 180 and the area is considered no freeze. This definition is explained in an 

equation in the Long-Term Pavement Performance Information Management System Pavement 

Performance Database User Reference Guide, FHWA-RD-03-088—see page 34 of the PDF version of the 

following: http://www.tfhrc.gov/pavement/ltpp/reports/03088/index.htm
23 

0

2000

4000

6000

8000

10000

12000

14000

0 250 500 750 1000 1250 1500 1750

Age, days

Compressive strength, psi

Cyl (no insulation) 

Core (no insulation) 

Cyl 

(i l ti ) Core 

(i l ti )

Figure 1. Graph. Plot of compressive strength versus age for test site in Arkansas. 

0 

2000 

4000 

6000 

8000 

10000 

12000 

0 500 1000 1500 2000 2500 3000 

Age, days 

Compressive strength, psi 

Cyl (no insulation) 

Core (no insulation) 

Cyl 

(i l t d) Core 

(i l t d)

Figure 2. Graph. Plot of compressive strength versus age for test site in Illinois. 
24 

0

2000

4000

6000

8000

10000

12000

0 500 1000 1500 2000 2500 3000

Age, days

Compressive strength, psi

North Carolina (Crushed Granite Melamine Water Reducer)

North Carolina (Crushed Granite Naphthalene Water Reducer)

North Carolina (Marine Marl Melamine Water Reducer)

North Carolina (Marine Marl Naphthalene Water Reducer)

Figure 3. Graph. Plot of strength gain for the different experiments 

(aggregate type and water reducer type) in North Carolina. 

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

0 500 1000 1500 2000 2500 3000

Age, days

Compressive strength, psi

Cyl (no insulation) 

Core (no insulation) 

Cyl 

(i l t d) Core 

(i l t d)

Figure 4. Graph. Plot of compressive strength versus age for test site in Nebraska. 
25 

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

0 500 1000 1500 2000 2500 3000

Age, days

Compressive strength, psi

Cyl (insulated)

Core (insulated)

Figure 5. Graph. Plot of compressive strength versus age for test site in New York 

(data available for insulated sections only). 

The plots in figure 3 show that the water reducer type generally has no effect on strength 

development. For both aggregates types (crushed granite and marine marl), the type of 

water reducer used (melamine or naphthalene) did not influence the magnitude of 

compressive strength or the rate of strength gain. However, figure 3 shows that the 

aggregate type does have an influence on the magnitude of compressive strength 

achieved (not strength gain). The mixes with crushed granite consistently had 16- to 

22-percent higher strength values over the 7-year period evaluated. 

As observed from the cores taken from Arkansas and Illinois, medium- to long-term 

strength development showed significant variations in the post-18-month strength; those 

from North Carolina, New York, and Nebraska showed relatively little variability and 

increased with age as expected. In general, the 5- to 7-year strengths for cores were 

greater than 55.2 MPa (8,000 psi), with the exception of the data from Illinois, which 

exhibited a significant drop in strength from a high of over 69 MPa (10,000 psi) after 

5 years to between 41.4 and 51.7 MPa (6,000 and 7,500 psi) after 7 years. The reason for 

this drop was not obvious. Table 9 presents a summary of the 1-day to 7-year concrete 

compressive strength and the 7-year to 28-day mean compressive strength for the 

combined data (insulated and uninsulated). 

For HES concrete, the minimum compressive strength after 24 hours should be 34.5 MPa 

(5,000 psi). This was achieved for most of the sites examined, with the exceptions of 

Illinois and Nebraska. The lower strengths in Illinois were caused by problems 

encountered during concrete placement and construction; those in Nebraska were caused 

by the use of a low coarse-aggregate content in the mixes to limit potential aggregaterelated durability problems. 
26 

Table 9 also shows that the rate of strength gain was generally higher for mixes with 

limestone (10 to 20 percent) than those with crushed granite and marine marl. 

Nevertheless, the low rate of strength gain could have been caused by many factors, 

including climate. 

Table 9. Summary of strength gain for combined compressive strength test data. 

Mean Core Compressive 

State Aggregate Type Strength, psi 

1-day* 28-day 7-yr** 

Percent Strength 

Gain (28-day 

to 7-yr) 

Arkansas Limestone 6223 7010 8078 15.22

Illinois Limestone 4453 5260 6353 20.78

Nebraska Limestone 3883 4586 5539 20.77

New York Limestone 5742 6297 7050 11.95

North Crushed granite 6831 7385 8136 10.16

Carolina Marine marl 5852 6200 6673 7.62

 *1-day compressive strength was backcasted from the longer-term data. 

 ** 7-yr strength for Arkansas was forecasted. 

 1 kPa = 6.9 psi 

The relationship between compressive strength obtained from cores and cylinders was 

also investigated. Core and cylinder compressive strength data were only available for the 

test pavement in New York, so the analysis was limited to only this site. The plot of 

compressive strength from cores and cylinders is presented in figure 6. Figure 6 shows a 

good relationship between the compressive strength values with a coefficient of 

determination R2

 value of 49 percent. Even though the magnitudes of compressive 

strength were close, compressive strength obtained from cores tended to be lower than 

those from cylinders. 

Bivariate Analysis—Static Elastic Modulus 

Figure 7 shows the static elastic modulus history for the three aggregate types analyzed. 

The figure shows that there was a slight decrease in moduli for crushed granite and 

limestone for the period 5 to 7 years while the moduli for marine marl remained constant. 

Even though an increase in moduli is typical for the ages evaluated, the data available 

were limited, and no firm conclusions could be reached. 

The relationship between compressive strength and static elastic modulus was also 

investigated by estimating elastic modulus using the model form(2): 

 / 0.5

PCC C E = αf (1) 
27 

where 

 EPCC = static modulus of elasticity 

 α = regression constant (57,000 for conventional concrete) 

 fc = compressive strength 

Figure 6. Graph. Plot of cores’ compressive strength 

 versus cylinders’ compressive strength. 

 

6000

7000

8000

9000

10000

6000 7000 8000 9000 10000 

Compressive strength (cylinder), psi 

Compressive strength (core), psi 

R 2 = 0.49 

N = 8 
28 

Figure 7. Graph. Plot of static elastic modulus versus age 

for the three aggregate types analyzed. 

Figures 8 through 10 show plots of the measured and predicted EPCC from compressive 

strength for crushed granite, marine marl, and limestone. For the aggregate types 

examined, α ranged from 26,500 to 43,000.(2) This was lower than the typical value of 

57,000 used for conventional concrete. The coefficient of determination R2 ranged from 

38 to 67 percent, which was reasonable for field data. 

Bivariate Analysis—RCPT and AC Impedance Tests 

Rapid Chloride Permeability Testing 

RCPT was performed on the core samples to determine chloride permeability and 

resistivity of the core specimens, respectively. Both RCPT and AC impedance test results 

provide an indication of the permeability or porosity of the concrete. A less permeable or 

less porous concrete material is expected to be more durable than one that is permeable or 

porous because of its susceptibility to moisture penetration. Permeable or porous cores 

are more likely to deteriorate from the influence of deicing salts as well as from freezethaw cycling. 

RCPT estimates concrete permeability by estimating the charge that flows through a test 

specimen over a set period of time. The higher the charge, the more permeable the 

concrete is. Table 10 presents a summary of the relationship between typical RCPT 

results (measured as charge in coulombs) and chloride permeability rating.(4) Plots of 

RCPT test results for the five test sites evaluated are presented in figures 11 through 15. 

For North Carolina, the test data were divided according to the aggregate type. 

0 

1000000

2000000

3000000

4000000

5000000

6000000

0 500 1000 1500 2000 2500 3000

Age, days 

Static elastic modulus, psi 

Crushed granite 

Marine marl 

Limestone
29 

In general, the charge passing through the concrete slightly increased with age or 

remained relatively constant. The only exception to this was for Nebraska. Chloride 

permeability for the sites evaluated (after 3 to 7 years’ placement) was classified using 

the ratings in table 10 and presented in table 11. Table 11 shows that the chloride 

permeability rating of the sites ranged from low to moderate. A moderate rating is quite 

high for a conventionally low water-cement ratio mixture (modified with water reducers). 

The abnormally high rating may be due to the presence of calcium nitrate (a set 

accelerating admixture) in the mix and hence does not necessarily mean the concrete mix 

is porous. In fact, the mix may have a moderate probability for durability-related distress. 

As shown in table 11, even though the absolute values of charge varied slightly with 

time, the chloride permeability rating remained relatively constant. With the exception of 

North Carolina, the chloride permeability rating of the test sites remained constant. This 

is in agreement with the observed visual distress that indicates little to no durabilityrelated problems 7 years after concrete placement. 

Figure 8. Graph. Plot of the measured and predicted EPCC 

from compressive strength for crushed granite. 

(Aggregate type = crushed granite) 

EPCC = 26500 f 

c

0.5 

R2 = 0.4486 

2000000

2500000

3000000

3500000

4000000

2000000 2500000 3000000

Measured static elastic modulus, psi 

Predicted static elastic 

modulus, psi 
30 

Figure 9. Graph. Plot of the measured and predicted EPCC 

from compressive strength for marine marl. 

Figure 10. Graph. Plot of the measured and predicted EPCC 

from compressive strength for limestone. 

Aggregate type = marine marl 

E PCC = 41000f c 

0.5 

R 2 = 0.3877 

3000000

3250000

3500000

3750000

4000000

3000000 3500000 4000000

Measured static elastic modulus, psi 

Predicted static elastic 

modulus, psi 

Aggregate type = limestone 

EPCC = 43000f c 

0.5 

R 2 = 0.6774 

3000000 

3500000 

4000000 

4500000 

5000000 

3000000 4000000 5000000 

Measured static elastic modulus, psi 

Predicted static elastic 

modulus, psi 
31 

Table 10. RCPT Chloride permeability ratings. 

RCPT Results 

(coulombs) 

Chloride 

Permeability 

> 4000 High 

2000 to 4000 Moderate 

1000 to 2000 Low 

100 to 1000 Very low 

< 100 Negligible 

Figure 11. Graph. Plot of charge passed versus concrete age for Arkansas. 

0

1000 

2000 

3000 

4000 

5000 

6000 

7000 

0 500 1000 1500 2000 

Age, days 

RCPT charge, coulombs 

Arkansas (Limestone) 
32 

Figure 12. Graph. Plot of charge passed versus concrete age for Illinois. 

Figure 13. Graph. Plot of charge passed versus concrete age for North Carolina. 

0

1000

2000

3000

4000

5000

6000

7000

0 500 1000 1500 2000 2500 3000

Age, days 

RCPT charge, coulombs 

Illinois (Limestone) 

0 

1000 

2000 

3000 

4000 

5000 

6000 

7000 

0 500 1000 1500 2000 2500 3000 

Age, days 

RCPT charge, coulombs 

North Carolina (Crushed granite) 

North Carolina (Marine marl) 
33 

Figure 14. Graph. Plot of charge passed versus concrete age for Nebraska. 

Figure 15. Graph. Plot of charge passed versus concrete age for New York. 

0

1000

2000

3000

4000

5000

6000

7000

0 500 1000 1500 2000 2500 3000

Age, days

RCPT charge, coulombs 

Nebraska (Limestone) 

0

1000

2000

3000

4000

5000

6000

7000

0 500 1000 1500 2000 2500 3000

Age, days 

RCPT charge, coulombs 

New York (Limestone)
34 

Table 11. Summary of chloride permeability for test sites evaluated. 

Chloride Permeability State Aggregate Type 0.5 year 1 year 3 year 5 year 7 year 

Arkansas Limestone — — Low Low — 

Illinois Limestone — — Moderate Moderate Moderate 

North 

Carolina 

Crushed granite Moderate Moderate — Moderate — 

North 

Carolina 

Marine marl Moderate Low Low Moderate Moderate 

Nebraska Limestone — — Moderate Moderate 

New York Limestone — — Moderate Moderate Moderate 
35 

Figures 16 through 18 present histograms showing comparisons of RCPT results 

measured from the top and bottom portions of the core specimens. Evaluating both the 

top and bottom portions of the slab separately was very important since durability-related 

distress such as D-cracking could be initiated from either end of the concrete slab. The 

information presented showed no obvious trend in the RCPT results for the top or bottom 

of the slab. This finding agreed with observation that showed obvious distress through the 

core specimens inspected. Because of the importance of the investigation to determine if 

there are significant differences in the top and bottom RCPT results, ANOVA was 

performed using the test data. The results are presented later in this chapter. 

AC Impedance 

The final durability indicator variable to be analyzed was the AC impedance, Z. As 

mentioned earlier, the impedance test was investigated as a viable alternative to RCPT. 

The test has a potential advantage over RCPT because it does not induce ionic diffusion 

within the specimen and, therefore, eliminates the effects of concentration gradients 

within the concrete. 

The AC impedance test was performed at two frequencies—100 and 1,000 Hz. However, 

because of inconsistencies in the testing procedure for the 1,000-Hz test, no reliable time 

series data were available. Therefore, the bivariate analysis was limited only to the 100-

Hz AC impedance test data conducted using the Nilsson soil resistance meter in two-pin 

mode. 

In general, higher measures of impedance within a concrete material indicate a less 

porous and more durable material able to withstand the effects of wet-dry, freeze-thaw, 

and other adverse climatic cycles. Figures 19 through 23 present plots of measured 

impedance versus age for the concrete samples evaluated from the different test sites. 

They show that impedance measured at 100 Hz generally remained constant or decreased 

slightly with age. This observation was similar to the RCPT results, where no obvious 

trend with time was determined. The observation also agrees with the visual distress data 

that showed no obvious deterioration in the concrete due to ASR or D-cracking. 

Because none of the sites evaluated showed any significant amounts of visual durabilityrelated distress, it would be premature to draw conclusions about whether the 100-Hz test 

result could accurately indicate the presence of durability-related distress. Even though 

Illinois and possibly other sites use deicing salts to free the pavements of ice during 

winter, the test results showed no adverse effect (such as increased variability). 
36 

0

1000

2000

3000

4000

5000

IL 1BIL 1BIL 2BIL 2B

Section ID

RCPT Charge, coulombs

RCPT (Top)

RCPT (Bot)

Figure 16. Bar chart. Histogram showing RCPT results from 

the top and bottom sections of concrete cores (Illinois). 

0

1000

2000

3000

4000

5000

NC_MG 1BNC_MG 2B

NC MG 1BNC MG 1BNC MG 2B

NC NG 1BNC NG 2B

NC_HCI

Section ID

RCPT Charge, coulombs

RCPT (Top)

RCPT (Bot)

Figure 17. Bar chart. Histogram showing RCPT results from the top 

and bottom sections of concrete cores (North Carolina). 
37 

0

1000

2000

3000

4000

5000

6000

NE SL 1BNE SL 4B

NY 2

NYS I88-2

Section ID

RCPT Charge, coulombs

RCPT (Top)

RCPT (Bot)

Figure 18. Bar chart. Histogram showing RCPT results from the top and 

bottom sections of concrete cores (Nebraska and New York). 

Figure 19. Graph. Plot of AC impedance versus age 

for concrete cores (Arkansas, limestone). 

0

500 

1000 

1500 

2000 

2500 

1000 1250 1500 1750 2000 

Age, days 

AC impedance, ohms 
38 

Figure 20. Graph. Plot of AC impedance versus age 

for concrete cores (Illinois, limestone). 

Figure 21. Graph. Plot of AC impedance versus age 

for concrete cores (North Carolina, granite). 

0

500 

1000 

1500 

2000 

2500 

1000 1500 2000 2500 3000 

Age, days 

AC impedance, ohms 

0

500

1000

1500

2000

1000 1500 2000 2500 3000

Age, days 

AC impedance, ohms 
39 

Figure 22. Graph. Plot of AC impedance versus age 

for concrete cores (Nebraska, limestone). 

Figure 23. Graph. Plot of AC impedance versus age 

for concrete cores (New York, limestone). 

0

500

1000

1500

2000

1000 1500 2000 2500 3000 

Age, days 

AC impedance, ohms 

0

500

1000 

1500 

2000 

100 1500 2000 2500 3000

Age, days 

AC impedance, ohms 
40 

Figure 24 shows the plot of RCPT versus AC impedance for the 100-Hz test. The plot 

shows clearly that there is a nonlinear exponential relationship between the 100-Hz AC 

impedance test and the RCPT. A model developed for relating RCPT results to the 100-

Hz AC impedance test results was as follows: 

(2) 

Statistics: 

 N = 32; R2

 = 92.5 percent 

where 

 ACIMPH = AC impedance measures at 100 Hz, ohms 

 ACIMPT = AC impedance measures at 1000 Hz, ohms 

 RCPT = RCPT results, coulombs 

y = 4953.8e-0.001x

R2 = 0.925

0

1000

2000

3000

4000

5000

0 500 1000 1500 2000 2500

RCPT Charge, Coulombs

100 Hz AC Impedance, Ohm

Figure 24. Graph. RCPT versus AC impedance for the 100-Hz test. 

Using equation 2 and the ratings presented in table 10, the ratings presented in table 12 

were developed for the 100-Hz AC impedance test. The presence of a functional 

correlation between the AC impedance measurements and the RCPT values is definitely 

encouraging. However, since the model shown in equation 2 was based on limited data, 

any attempt to use it beyond the scope of this work is not encouraged until further 

research is done. 

Table 12. RCPT and 100-Hz AC impedance test ratings. 

RCPT Results 

(coulombs) 

100-Hz AC 

Impedance (ohms) 

Chloride 

Permeability 

> 4000 < 90 High 

2000 to 4000 90 to 670 Moderate 

1000 to 2000 670 to 1800 Low 

100 to 1000 1800 to 4480 Very low 

< 100 > 4480 Negligible 

ACIMPH = 4953.8(e-0.001RCPT) 
41 

Analysis of Variance 

The bivariate analysis was followed by a comprehensive ANOVA to determine their 

statistical significance. The hypothesis tested: 

 

• Influence of early-age curing on core compressive strength and RCPT results. 

• Influence of aggregate type on core compressive strength and RCPT results. 

• Whether a significant difference existed between top and bottom RCPT results. 

The results of ANOVA are summarized and discussed in the following sections. 

Influence of Early-Age Curing on Core Compressive Strength and RCPT Results 

For this analysis, the data were grouped according to location/climate (five treatments) 

and curing method (two treatments). The durability indicator variables used were core 

compressive strength and RCPT test result (charge in coulombs). All the data from the 

different age groups were grouped together for this analysis to ensure that a reasonable 

sample size for analysis was obtained. Tables 13 and 14 present summaries of ANOVA 

results (Duncan’s multiple-range test of comparison of mean) for the effect of curing 

method on the durability indicator variable compressive strength and chloride 

permeability. 

The information presented in tables 13 and 14 confirms the observed trends (see figures 1 

through 5) that the curing method used had no significant impact on the long-term 

strength development or chloride permeability of the concrete. However, this observation 

does not imply that insulated curing is not useful for HES concrete. It is definitely useful 

for VES gain, as reported in the original SHRP study.(1) 

Table 13. Summary of ANOVA results for the effect of curing method on strength.

Location Variable Class Mean 

Value 

Duncan 

Class* Comments 

Arkansas Compressive None 8932 A 

strength, psi Plastic sheeting 

(insulated) 

9628 A 

No significant 

difference 

Illinois Compressive None 7443 A 

strength, psi Plastic sheeting 

(insulated) 

7598 A 

No significant 

difference 

North None 8223 A 

Carolina 

Compressive 

strength, psi Plastic sheeting 

(insulated) 

8519 A 

No significant 

difference 

Nebraska Compressive None 6330 A 

strength, psi Plastic sheeting 

(insulated) 

6542 A 

No significant 

difference 

New York Compressive None — — 

strength, psi Plastic sheeting 

(insulated) 

— — 

Data available only for 

insulated sections 

* Duncan’s multiple range test; those with the same letter are not significantly different. 
42 

Table 14. Summary of analysis of variance results for the effect of curing method 

on concrete permeability.

Location Variable Class Mean 

Value 

Duncan 

Class* Comments 

Arkansas Charge, None 983 A 

coulombs Plastic sheeting 

(insulated) 

1153 A 

No significant 

difference 

Illinois Charge, None 2457 A 

coulombs Plastic sheeting 

(insulated0 

2607 A 

No significant 

difference 

North Carolina Charge, None 2509 A 

coulombs Plastic sheeting 

(insulated) 

2652 A 

No significant 

difference 

Nebraska Charge, None 2271 A 

coulombs Plastic sheeting 

(insulated) 

2957 A 

No significant 

difference 

New York Charge, None — — 

coulombs Plastic sheeting 

(insulated) 

— — 

Data available only for 

insulated sections 

* Duncan’s multiple-range test; those with the same letter are not significantly different. 

Influence of Aggregate Type on Core Compressive Strength and RCPT Results

For this analysis, the data were grouped according to aggregate type. The strength 

indicator used was compressive strength of cores; the durability indicator used was the 

RCPT result (charge in coulombs), which is an indicator of concrete permeability. All the 

data from the different age groups were grouped together for this analysis. Tables 15 and 

16 present summaries of the ANOVA (Duncan’s multiple-range test of comparison of 

means). 

Table 15. Summary of analysis of variance results for the effect 

of aggregate type on strength.

Variable Class Mean Value Duncan 

Class* Comments 

Crushed 

granite 

9372 A 

Marine marl 7486 B 

Compressive 

strength, psi 

Limestone 7877 B 

Significant 

difference 

between crushed 

granite and others 

 * Duncan’s multiple-range test; those with the same letter are not significantly different. 
43 

Table 16. Summary of analysis of variance results for the effect of 

aggregate type on concrete permeability.

Variable Class Mean Value Duncan 

Class* Comments 

Crushed 

granite 

2414 A 

Marine marl 2300 A 

Charge, 

coulombs 

Limestone 1808 A 

No significant 

difference 

 * Duncan’s multiple-range test; those with the same letter are not significantly different. 

The information presented in tables 15 and 16 confirms the observed trends—the 

aggregate type has a significant impact on the long-term strength development, with the 

concrete mix made with crushed granite having the highest strength values. There was, 

however, no difference in the strengths of concrete made from marine marl or limestone. 

Aggregate type had no significant effect on concrete chloride permeability, as shown in 

table 16. 

Evaluation of Top and Bottom RCPT Results 

The RCPT results from measurements made on the top and bottom portions of the same 

core specimen were evaluated to determine if there was a significant difference in their 

values. Table 17 presents summaries of ANOVA results (test of significance (F-test) and 

Duncan’s multiple range test of comparison of mean). 

The information presented in table 17 confirms the observed trends seen in figures 16 

through 18—there was no significant difference in chloride permeability for the top and 

bottom portions of the core specimens. This was also in agreement with the observed 

visual distress survey that showed no significant distress throughout the entire core 

specimen evaluated. 

Table 17. Summary of analysis of variance results for evaluating 

specimen RCPT results.

Variable Class Mean 

Value 

Duncan 

Class* Comments 

Charge, Top of specimen 2944 A 

coulombs Bottom of specimen 2376 A 

No significant 

difference 

 * Duncan’s multiple-range test; those with the same letter are not significantly different. 

45 

CHAPTER 4. CONCLUSIONS AND RECOMMENDATIONS 

CONCLUSIONS 

This study was intended to investigate the durability and integrity of HES concrete 

patches built in Arkansas, Illinois, Nebraska, New York, and North Carolina. Strength, 

modulus, resistance to chloride ion penetration, and visual condition of the patches were 

used as durability indicators. The results and recommendations presented in this report 

are based on a comprehensive study of the test data using statistical methods and 

engineering principles. Chapter 3 discussed in detail the effects of climate and material 

properties on the HES concrete durability. The following key observations were made 

from the data analysis: 

• In most cases, the concrete continued to gain strength and modulus with time over 

the entire performance monitoring period. 

• The resistance to chloride ion penetration increased only slightly with time in 

some instances and was relatively constant in other cases. 

• Water reducer type had no significant effect on long-term durability. 

• Curing method (insulated versus uninsulated) also had no significant effect on 

long-term compressive strength or the other durability indicators. 

• Aggregate type used in the concrete mix had a significant effect on the magnitude 

of compressive strength but no effect on strength gain, chloride permeability, or 

AC impedance. 

• Concrete mixtures made with crushed granite had the highest compressive 

strengths, typically 16 to 22 percent greater than that for limestone and marine 

marl. 

• The RCPT test results had a good correlation (90 percent) with the 100-Hz AC 

impedance test results. 

• There were insufficient data to determine the reliability of all three durability 

indicator variables. 

RECOMMENDATIONS 

The study was successful to a large extent in that it demonstrated that HES concrete 

patches, when built using a variety of methods and materials and exposed to different 

climatic conditions, can perform adequately in the field with no extraordinary signs of 

durability-related distresses. However, since the study only spanned approximately 7 

years into the life of the patches, additional data will be necessary to study in greater 

detail the effects of climate, construction, and site conditions that influence HES concrete 

durability. 

It is therefore recommended that more data be collected as the patches age, and that these 

data be analyzed to make further observations of the long-term durability of these 

materials. 

47 

APPENDIX A. DISTRESS SURVEY MAPS 

Distress survey maps representing the condition of the various patches are presented in 

figures 25 through 40 in this appendix. The circular dots on the maps indicate core 

locations. The patches in Arkansas, New York, and North Carolina did not show 

significant deterioration over time. Therefore, for these sections, distress maps are 

provided only for the years 1994 and 1998. On the other hand, sections in Illinois and 

Nebraska showed more pronounced deterioration over time. For these sites, distress maps 

are provided for all the years in which field surveys were conducted. 
48 

Section ID: NC 1

Inspection Date: 11/22/94 

Comments: _________________________________________________________________________________________________

___________________________________________________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

45' 50' 55' 60' 65' 70' 75' 80' 85' 90'

Comments: No signs of D-cracking or scaling.______________________________________________________________

___________________________________________________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

Figure 25. Graph. Distress map for patch NC-1 in North Carolina—1994. 

Section ID: NC 1

Inspection Date: 11/3/98 

Comments: _________________________________________________________________________________________________

___________________________________________________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

45' 50' 55' 60' 65' 70' 75' 80' 85' 90'

Comments: No signs of D-cracking or scaling._____________________________________________________________________

No change in condition (1995; 1996; 1997; 1998).__________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

Figure 26. Graph. Distress map for patch NC-1 in North Carolina—1998. 
49 

Section ID: NC-2

Inspection Date: 11/22/94 

Comments: _________________________________________________________________________________________________

___________________________________________________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

135' 140' 145' 150' 155' 160' 165' 170' 175' 180'

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

135' 140' 145' 150' 155' 160' 165' 170' 175' 180'

Comments: Wide joint at location 120'._______________________________________________________________________

__________________________________________________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

90' 95' 100' 105' 110' 115' 120' 125' 130' 135'

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

90' 95' 100' 105' 110' 115' 120' 125' 130' 135'

Figure 27. Graph. Distress map for patch NC-2 in North Carolina—1994. 

Section ID: NC-2

Inspection Date: 11/3/98 

Comments: _________________________________________________________________________________________________

___________________________________________________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

135' 140' 145' 150' 155' 160' 165' 170' 175' 180'

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

135' 140' 145' 150' 155' 160' 165' 170' 175' 180'

Comments: Wide joint at location 120'._______________________________________________________________________

__________________________________________________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

90' 95' 100' 105' 110' 115' 120' 125' 130' 135'

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

90' 95' 100' 105' 110' 115' 120' 125' 130' 135'

Figure 28. Graph. Distress map for patch NC-2 in North Carolina—1998. 
50 

Section ID: AR-1

Inspection Date: 12/2/94

Comments: All joints are well sealed with HP sealant. No signs of scaling or D-cracking (12/2/94)

___________________________________________________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

Traffic

Map cracking

Figure 29. Graph. Distress map for patch AR-1 in Arkansas—1994. 

Section ID: AR-1

Inspection Date: 9/19/95

Comments: All joints are well sealed with HP sealant. No signs of scaling or D-cracking (12/2/94)

Some surface crazing was noted on slab 2 (1995). Joint seals remain in good condition._____________________________________

Section overlaid after 1995 inspection____________________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

Traffic

Map cracking

Figure 30. Graph. Distress map for patch AR-1 in Arkansas—1995. 
51 

Section ID: AR-2

Inspection Date: 9/19/95 Traffic

Comments: Slight map cracking on slab no.2. No signs of D-cracking or scaling.

___________________________________________________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

Map cracking

Figure 31. Graph. Distress map for patch AR-2 in Arkansas—1994. 

Section ID: AR-2

Inspection Date: 9/19/95 Traffic

Comments: Slight map cracking on slab no.2. No signs of D-cracking or scaling.

___________________________________________________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

Map cracking

Figure 32. Graph. Distress map for patch AR-2 in Arkansas—1995. 
52 

Section ID: NY 

Inspection Date: 11/21/94

Comments: Rough texture on all slabs. The mixture was very dry when placed.

___________________________________________________________________________________________________________

0' 5' 10' 15' 20' 25' 30' 35' 40'

2'

4'

6'

8'

0'

12'

10'

40' 45' 50' 55' 60' 65' 70' 75' 80'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40'

2'

4'

6'

8'

0'

12'

10'

40' 45' 50' 55' 60' 65' 70' 75' 80'

2'

4'

6'

8'

0'

12'

10'

40' 45' 50' 55' 60' 65' 70' 75' 80'

2'

4'

6'

8'

0'

12'

10'

Traffic

Figure 33. Graph. Distress map of section in New York—1994. 

Section ID: NY 

Inspection Date: 11/9/98

Comments: Rough texture on all slabs. The mixture was very dry when placed.

Some spalling observed on longitudinal edge joint (1995). No noticeable change from last year (1996; 1997; 1998).

___________________________________________________________________________________________________________

0' 5' 10' 15' 20' 25' 30' 35' 40'

2'

4'

6'

8'

0'

12'

10'

40' 45' 50' 55' 60' 65' 70' 75' 80'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40'

2'

4'

6'

8'

0'

12'

10'

40' 45' 50' 55' 60' 65' 70' 75' 80'

2'

4'

6'

8'

0'

12'

10'

40' 45' 50' 55' 60' 65' 70' 75' 80'

2'

4'

6'

8'

0'

12'

10'

Traffic

Spalling at lane-shoulder joint

Figure 34. Graph. Distress map of section in New York—1998.
53 

Comments: Insulated. Some scaling, which appear to be construction related. Much cleaner finish than IL-2.

___________________________________________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

Section ID: IL-1

Inspection Date: 10/20/94

HL

Traffic

HL

indentations

HL

Section ID: IL-2

Inspection Date:10/20/94 

Comments: Noninsulated. Shrinkage cracks, minor map cracking, and scaling. Surrounding pavement had been milled.

___________________________________________________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

Scaling

Traffic

Map cracking

L

Figure 35. Graph. Distress maps for patches IL-1 and IL-2 in Illinois—1994. 
54 

Comments: Insulated. Some scaling, which appear to be construction related. Much cleaner finish than IL-2.

___________________________________________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

Section ID: IL-1

Inspection Date: 9/11/95

L L

L

Traffic

L

L

indentations

L

Section ID: IL-2

Inspection Date: 9/11/95 

Comments: Noninsulated. Shrinkage cracks, minor map cracking, and scaling. Surrounding pavement had been milled.

___________________________________________________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

Scaling

Traffic

Map cracking

L

L

L

L

Figure 36. Graph. Distress maps for patches IL-1 and IL-2 in Illinois—1995. 
55 

Comments: Insulated. Some scaling, which appear to be construction related. Much cleaner finish than IL-2.

__________________________________________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

Section ID: IL-1

Inspection Date: 10/11/96

L L

L

Traffic

L

L

indentations

L

L

L

Section ID: IL-2

Inspection Date: 10/11/96 

Comments: Noninsulated. Shrinkage cracks, minor map cracking, and scaling. Surrounding pavement had been milled.

___________________________________________________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

Scaling

Traffic

Map cracking

L

L

L

L

Figure 37. Graph. Distress maps for patches IL-1 and IL-2 in Illinois—1996. 
56 

Comments: Insulated. Some scaling, which appear to be construction related. Much cleaner finish than IL-2.

_Slight increase in map cracking (1997)________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

Section ID: IL-1

Inspection Date: 1/12/98

L L

L

Traffic

L

L

indentations

L

L

L

Section ID: IL-2

Inspection Date: 1/12/98 

Comments: Noninsulated. Shrinkage cracks, minor map cracking, and scaling. Surrounding pavement had been milled.

_Slight increase in map cracking (1997) ________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

Scaling

Traffic

Map cracking

L

L

L

L

Figure 38. Graph. Distress maps for patches IL-1 and IL-2 in Illinois—1997. 
57 

Comments: Insulated. Some scaling, which appear to be construction related. Much cleaner finish than IL-2.

_Slight increase in map cracking (1997)________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

Section ID: IL-1

Inspection Date: 1/12/98

L L

L

Traffic

L

L

indentations

L

L

L

Section ID: IL-2

Inspection Date: 1/12/98 

Comments: Noninsulated. Shrinkage cracks, minor map cracking, and scaling. Surrounding pavement had been milled.

_Slight increase in map cracking (1997) ________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

Scaling

Traffic

Map cracking

L

L

L

L

Figure 39. Graph. Distress maps for patches IL-1 and IL-2 in Illinois—1998. 
58 

Section ID: NE -1

Inspection Date: 10/11/94

Comments: Located ~ 700 ft west of Breslav Creek Bridge.

________________________________________________________________ ___________________________________________

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

0' 5' 15' 20' 25' 30' 35' 40' 45' 50'

Replaced with State's

standard patch mix.

M

Traffic

L

Section ID: NE-2

Inspection Date: 10/11/94

Comments: _________________________________________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 45'

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 35' 40' 45'

Traffic

M M

Figure 40. Graph. Distress maps for patches NE-1 and NE-2 in Nebraska—1994. 
59 

Section ID: NE -1

Inspection Date: 9/18/95

Comments: Located ~ 700 ft west of Breslav Creek Bridge.

_No significant change in condition (1995)._____________________ ______________________________________ _____

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

0' 5' 15' 20' 25' 30' 35' 40' 45' 50'

Replaced with State's

standard patch mix.

M

Traffic

L

Section ID: NE-2

Inspection Date: 9/18/95

Comments: _________________________________________________________________________________________________

___________________________________________________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 35' 40' 45'

Traffic

M M

Map cracking

Map cracking in the middle 1/3 of the slab

Figure 41. Graph. Distress maps for patches NE-1 and NE-2 in Nebraska—1995. 
60 

Section ID: NE -1

Inspection Date: 9/26/96

Comments: Located ~ 700 ft west of Breslav Creek Bridge.

_No significant change in condition (1995)._____________________ ______________________________________ _____

_No significant change in condition other than progress of surface cracks shown on the map (1996). _____________________

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

0' 5' 15' 20' 25' 30' 35' 40' 45' 50'

Replaced with State's

standard patch mix.

M

Traffic

L

Section ID: NE-2

Inspection Date: 9/26/96

Comments: _________________________________________________________________________________________________

___________________________________________________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 35' 40' 45'

Traffic

M M

Map cracking

Map cracking in the middle 1/3 of the slab

Figure 42. Graph. Distress maps for patches NE-1 and NE-2 in Nebraska—1996. 
61 

Section ID: NE-1

Inspection Date: 10/8/97

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

0' 5' 15' 20' 25' 30' 35' 40' 45' 50'

Replaced with State's

standard patch mix.

M

Traffic

L

Comments: Located ~700 ft west of Breslav Creek Bridge. 

No significant change in condition (1995). 

No significant change in condition other than progress of surface cracks shown on the map (1996). 

Increase in map cracking (1997). 

Section ID: NE-2

Inspection Date: 9/8/97

Comments: _________________________________________________________________________________________________

___________________________________________________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 35' 40' 45'

Traffic

M M

Map cracking

Map cracking in the middle 1/3 of the slab

Figure 43. Graph. Distress maps for patches NE-1 and NE-2 in Nebraska—1997. 
62 

Section ID: NE -1

Inspection Date: 10/13/98

Comments: Located ~ 700 ft west of Breslav Creek Bridge.

_No significant change in condition (1995)._____________________ ______________________________________ _____

_No significant change in condition other than progress of surface cracks shown on the map (1996). _____________________

Increase in map cracking (1997). _____________ __________________________________________________________

_Significant increase in map cracking (1998).___________________ ____________________________________________________

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

0' 5' 15' 20' 25' 30' 35' 40' 45' 50'

Replaced with State's

standard patch mix.

M

Traffic

L

Section ID: NE-2

Inspection Date: 10/13/98

Comments: _________________________________________________________________________________________________

___________________________________________________________________________________________________________

2'

4'

6'

8'

0'

12'

10'

2'

4'

6'

8'

0'

12'

10'

0' 5' 10' 15' 20' 25' 30' 35' 40' 35' 40' 45'

Traffic

M M

Map cracking

Map cracking in the middle 1/3 of the slab

Figure 44. Graph. Distress maps for patches NE-1 and NE-2 in Nebraska—1998. 
63 

REFERENCES 

1. Zia, P., S.A. Ahmad, M.L. Leming, J.J. Schemmel, and R.P. Elliot, Mechanical 

Behaviour of High Performance Concrete, Vol. 4: High Early Strength Concrete. 

Strategic Highway Research Program, Washington, DC, 1993. 

2. Mindess, S., and J.F. Young, Concrete. Prentice Hall, Englewood Cliffs, NJ, 

1981. 

3. Neter, J., W. Wasserman, and M.H. Kunter, Applied Linear Statistical Models. 

Richard D. Irwin, Inc., Homewood, IL, 1989. 

4. Pfeifer, D.W., D.B. McDonald, and P.D. Krauss, “The Rapid Chloride 

Permeability Test and Its Correlation to 90-Day Chloride Ponding Test,” Portland 

Cement Institute Journal. January–February, 1994.