Highway Concrete Pavement Technology

Development and Testing: Volume II—

Field Evaluation of Strategic Highway

Research Program (SHRP) C-203 Test 

Sites (Freeze-Thaw Resistance)

PUBLICATION NO. FHWA-RD-02-083 AUGUST 2006

Research, Development, and Technology

Turner-Fairbank Highway Research Center

6300 Georgetown Pike

McLean, VA 22101-2296
Foreword 

This report documents results from 2 field sites, which include a total of 18 test sections in 

Minnesota and Ohio. The sites were monitored for long-term performance to verify the 

effectiveness of freeze-thaw resistance technology. The performance monitoring included annual 

distress surveys and physical testing of cores taken from the concrete slabs at both sites. Wave 

velocity was measured at joints at the Ohio site to evaluate some treatments for D-cracking 

mitigation. 

The field test sites were installed in 1992 as a part of Strategic Highway Research Program 

(SHRP) Contract C-203, “Resistance of Concrete to Freezing and Thawing.” The purpose of 

both installations was to validate the current frost resistance technology for new concrete in a 

field environment. In addition, at the Ohio site an additional evaluation was conducted to 

examine the effectiveness of methods to treat existing D-cracked concrete pavements to mitigate 

the effect of future D-cracking. 

Results from the field and laboratory testing over a 6-year period after construction (1992 to 

1998) showed very little visual distress at the surface or physical distress of portland cement 

concrete (PCC) cores taken from the interior portions of the test sections. A description of the 

field sites and monitoring results are provided. Conclusions reached and recommendations for 

further study are then presented. 

Gary L. 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.
Technical Report Documentation Page 

 1. Report No. 

FHWA-RD-02-083

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

 5. Report Date 

August 2006

 6. Performing Organization Code 

 4. Title and Subtitle 

 STRATEGIC HIGHWAY RESEARCH PROGRAM 

Highway Concrete Pavement Technology Development and Testing: Volume II—Field 

Evaluation of Strategic Highway Research Program (SHRP) C-203 Test Sites (FreezeThaw Resistance) 

 7. Author(s) 

 Donald J. Janssen, University of Washington 

 8. Performing Organization Report No. 

 10. Work Unit No. (TRAIS) 

 11. Contract or Grant No. 

DTFH61-94-C-00009

 9. Performing Organization Name and Address 

ERES Division of Applied Research Associates, Inc. 

505 W. University Avenue 

Champaign, IL 61820-3915

 13. Type of Report and Period Covered 

Final Report 12. Sponsoring Agency Name and Address 

 Office of Engineering and Highway Operations R&D 

 Federal Highway Administration 

 6300 Georgetown Pike 

 McLean, VA 22101-2296

 14. Sponsoring Agency Code 

 15. Supplementary Notes 

FHWA Contracting Officer's Technical Representative: Monte Symons, P.E. This work was conducted by Professor Donald 

J. Janssen under subcontract at the University of Washington.

 16. Abstract 

Field test sections were constructed during 1992 as part of the Strategic Highway Research Program (SHRP) 

investigation of the frost resistance of concrete. The first freeze-thaw-related deterioration expected for 

pavement concrete exposed to de-icing salt would be salt scaling. Unfortunately, the test sections constructed in 

Ohio were diamond-ground between construction and the first visit of the monitoring team. The diamondground surface did not deteriorate over time. Internal deterioration of the Ohio test sections was either not 

detected or was believed to be caused by a mechanism other than freeze-thaw. Freeze-thaw deterioration was 

not noticed, either, in the Minnesota test sections (not exposed to deicing salts), though freeze-thaw tests 

conducted on specimens cut from the test sections 6 years after construction showed significantly different 

performance than specimens prepared and tested at the time of test section construction. For both the Ohio and 

Minnesota test sections, only 6 years of winter exposure would not be adequate to evaluate potential long-term 

performance thoroughly. Though the Ohio sections have been overlaid, making further monitoring impossible, 

the Minnesota sections are still exposed. Additional monitoring of these sections is recommended, along with 

providing salt exposure to the sections to determine their resistance to salt scaling. The D-cracking mitigation 

study indicated that in many cases the D-cracking returned after 6 years, independent of the mitigation technique 

tried. Additional testing would be required to make further evaluations.

 17. Key Words 

Concrete pavement, durability, compressive strength, 

rapid chloride permeability test, AC impedance test, lifecycle cost

18. Distribution Statement 

No restrictions. This document is available to the 

public through the National Technical Information 

Service, Springfield, VA 22161.

 19. Security Classif. (of this report) 

Unclassified

20. Security Classif. (of this page) 

Unclassified 

 21. No of Pages 

47

22. Price 

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

ii 
TABLE OF CONTENTS 

Chapter 1. Introduction................................................................................................................ 1

Chapter 2. Minnesota Freezing and Thawing Field Sections ................................................... 3

Minnesota Winter Weather Conditions...................................................................................... 3 

Description of Minnesota Sections ............................................................................................ 3 

Condition Surveys of Minnesota Sections, 1994 through 1998................................................. 5 

Testing of Cores from Minnesota Sections, 1994 to 1998......................................................... 9 

Followup Freeze-Thaw Testing of Specimens from Minnesota Sections ............................... 10 

Chapter 3. Ohio Test Sections.................................................................................................... 11

Ohio Winter Weather Conditions ............................................................................................ 11 

Description of the Ohio Early-Strength Freeze-Thaw and D-Cracking Mitigation 

Experimental Sections.............................................................................................................. 11 

Condition Survey of Ohio Sections, 1994 through 1998 ......................................................... 15 

Testing of Cores from Ohio Sections, 1994 to 1998................................................................ 18 

Ohio D-Cracking Mitigation Sections ..................................................................................... 18 

D-Cracking Mitigation Results ................................................................................................ 22

Chapter 4. Conclusions and Recommendations....................................................................... 23

Freeze-Thaw Results................................................................................................................ 23 

D-Cracking Mitigation............................................................................................................. 24 

Appendix A Condition Survey of Mn/ROAD PCC Test Pads 

(SHRP C-203 Pads) in 1994, 1998, and 2001 ....................................................................... 25

Appendix B. Information and Photos on Ohio Freeze-Thaw Full-depth Repairs................ 37

References.................................................................................................................................... 41

iii 
LIST OF FIGURES 

Figure 1. Test panels for mixture MN7 showing cores taken in 1994............................................ 5 

Figure 2. Photograph of Minnesota test section 1 (1998). Most of the surface texture 

(brooming) is still visible. Sand particles up to 2 mm are visible in a very lightly 

scaled surface. ......................................................................................................................... 8 

Figure 3. Photograph of Minnesota test section 5 (1998).............................................................. 9 

Figure 4. Surface cracking in patch, mixture I3 (parallel lines on surface are 

the result of surface diamond grinding soon after construction). ......................................... 17 

Figure 5. Deterioration in patch (left) in wheelpath, mixture I4 (surface has been diamond 

ground, and note longitudinal paint strip along pavement edge at bottom of photo). .......... 17 

Figure 6. Field NDT velocity measurements................................................................................ 22 

Figure A1. Section MN1—1994................................................................................................... 28 

Figure A2. Section MN1—May 2001. ......................................................................................... 28 

Figure A3. Section MN2—1994................................................................................................... 29 

Figure A4. Section MN2—May 2001. ......................................................................................... 29 

Figure A5. Section MN3—1994................................................................................................... 30 

Figure A6. Section MN3—May 2001. ......................................................................................... 30 

Figure A7. Section MN4—1994................................................................................................... 31 

Figure A8. Section MN4—May 2001. ......................................................................................... 31 

Figure A9. Section MN5—1994................................................................................................... 32 

Figure A10. Section MN5—May 2001. ....................................................................................... 32 

Figure A11. Section MN6—1994................................................................................................. 33

Figure A12. Section MN6—May 2001. ....................................................................................... 33 

Figure A13. Section MN7—1994................................................................................................. 34

Figure A14. Section MN7—May 2001. ....................................................................................... 34 

Figure A15. Section MN8—1994................................................................................................. 35

Figure A16. Section MN8—May 2001. ....................................................................................... 35 

Figure B1. Typical surface textures after diamond grinding, Ohio test sections.......................... 37 

Figure B2. Schematic diagram of SASW testing (from Malhorta and Carino, 

Handbook on Nondestructive Testing on Concrete, CRC Press, New York, 1991.)............ 37 

Figure B3. SASW testing at the Ohio test sections. ..................................................................... 38 

Figure B4. Typical R-wave velocity versus vibration frequency plot.......................................... 39 

iv 
LIST OF TABLES 

Table 1. Summary of winter weather conditions, Minnesota sections. .......................................... 4 

Table 2. Summary of Minnesota sections and PCC mixtures. ....................................................... 5 

Table 3. Summary of laboratory durability test results from the Minnesota site— 

air entrainment. ....................................................................................................................... 6 

Table 4. Summary of laboratory durability test results from the Minnesota site— 

freeze-thaw testing. ................................................................................................................. 7 

Table 5. Dynamic modulus of Minnesota cores. .......................................................................... 10 

Table 6. Results of followup freeze-thaw testing of Minnesota sections. .................................... 10 

Table 7. Summary of winter weather conditions, Ohio sections. ................................................. 12 

Table 8. Summary of laboratory durability test results on Ohio test sections— 

air entrainment. ..................................................................................................................... 13 

Table 9. Summary of laboratory durability test results on Ohio test sections— 

freeze-thaw testing. ............................................................................................................... 14 

Table 10. Distress summary of Ohio sections. ............................................................................. 15 

Table 11. Faulting summary of Ohio sections.............................................................................. 16 

Table 12. Ohio early-strength sections. ........................................................................................ 18 

Table 13. Ohio D-cracking mitigation sections. ........................................................................... 19 

Table 14. Summary of Ohio core dynamic modulus and field nondestructive 

testing (NDT). ....................................................................................................................... 21 

v 

CHAPTER 1. INTRODUCTION 

This report documents results from 2 field sites, which include a total of 18 test sections: 

• Maintenance area of the Minnesota Road Research Project (Mn/ROAD) test site, about 40 

miles northwest of Minneapolis, MN (8 test sections non-trafficked). 

• Route 2 in Erie and Lorain Counties near Vermilion, OH (10 test sections placed as fulldepth patches in an old D-cracked pavement). 

The sites were monitored for long-term performance to verify the effectiveness of freeze-thaw 

resistance technology. The performance monitoring included annual distress surveys and 

physical testing of cores taken from the concrete slabs at both sites. Wave velocity was measured 

at joints at the Ohio site to evaluate some treatments for D-cracking mitigation. 

The field test sites were installed in 1992 in Minnesota and Ohio as a part of Strategic Highway 

Research Program (SHRP) Contract C-203, “Resistance of Concrete to Freezing and Thawing.” 

The purpose of both installations was to validate the current frost resistance technology for new 

concrete in a field environment. In addition, at the Ohio site another evaluation was conducted to 

examine the effectiveness of methods to treat existing D-cracked concrete pavements to mitigate 

the effect of future D-cracking. 

Briefly, results from the field and laboratory testing over a 6-year period after construction (1992 

to 1998) showed very little visual distress at the surface or physical distress of portland cement 

concrete (PCC) cores taken from the interior portions of the test sections. Deterioration of some 

of the Ohio patches (especially in the wheel-path near transverse joints) was observed, but this is 

not believed to be due to a direct freeze-thaw mechanism. Some deterioration from D-cracking 

was observed at the joints of the original Ohio pavement. Further monitoring of the Minnesota 

site is recommended to obtain long-term distress and PCC deterioration information for use in 

validating the C-203 recommendations. 

A description of the Minnesota field sites and monitoring results are provided first, followed by a 

description of the Ohio field sites and monitoring results. Conclusions reached and 

recommendations for further study are then presented. 

1 

CHAPTER 2. MINNESOTA FREEZING AND THAWING FIELD SECTIONS 

The purpose of the test sections installed in Minnesota was to determine the influence of varying 

fly ash contents and air contents on the frost resistance of concrete. Fly ash contents of 15 and 30 

percent (by mass) cementitious material as well as zero-fly ash mixtures were placed at various 

air contents. These sections were placed in October of 1992 and were monitored from 1994 

through 1998. An additional survey was conducted in 2001 to obtain up-to-date performance 

information. 

Caution should be exercised in evaluating results because the sections were not on trafficked 

pavement and did not experience de-icing salt application. However, snow was removed from 

the sections on a regular basis, so this pavement was certainly subjected to normal freeze-andthaw cycles. 

MINNESOTA WINTER WEATHER CONDITIONS 

A summary of climatic exposure conditions for the Minnesota sections is given in table 1. These 

sections were subjected to severe winter freezing and thawing temperatures. The air freeze-thaw 

cycles range from 140 to 170 per year over this time period. 

DESCRIPTION OF MINNESOTA SECTIONS 

The Minnesota sections consist of 8 concrete pads of 4.6 meter (m) by 6.1 m at the Mn/ROAD 

test site maintenance yard. The sections were placed at the maintenance yard so that they would 

be subjected to environmental loads only. Each pad was quartered by making two saw cuts; 

hence, each section consists of 4 panels that are 2.3 m by 3.0 m. 

The eight pads comprise eight test sections constructed of eight different mixes. These 

installations were developed to look at pozzolan content and air-void parameters. These 

experimental variables included 1.5, 2.5, and 5.5 percent air entrainment, and 0 and 30 percent 

fly ash by weight of cementitious material. A section containing a proprietary admixture that 

produces high-carbon concrete was also included (section 8). A summary of the various mix 

types is provided in table 2. One of the sections was the same as the conventional paving mix 

used on many of the Mn/ROAD concrete pavement sections (section 1). 

3 
Table 1. Summary of winter weather conditions, Minnesota sections.* 

Month/Year Monthly Low 

Temperature, °C 

Days Below 

0 °C (Air) 

Days Below 

–18 °C (Air) 

October 1992 -6 11 – 

November 1992 -9 25 – 

December 1992 -24 29 6 

January 1993 -27 30 12 

February 1993 -24 28 9 

March 1993 -19 30 7 

April 1993 -8 9 – 

October 1993 -3 11 – 

November 1993 -16 25 – 

December 1993 -26 30 7 

January 1994 -33 31 17 

February 1994 -27 28 12 

March 1994 -12 27 – 

April 1994 -8 13 – 

October 1994 -2 4 – 

November 1994 -13 20 – 

December 1994 -19 31 1 

January 1995 -24 30 5 

February 1995 -24 28 9 

March 1995 -20 18 4 

April 1995 -15 9 – 

October 1995 -4 3 – 

November 1995 -17 29 – 

December 1995 -23 31 5 

January 1996 -31 31 18 

February 1996 -36 28 8 

March 1996 -23 28 8 

April 1996 -6 20 – 

October 1996 -9 9 – 

November 1996 -24 27 4 

December 1996 -33 31 9 

January 1997 -28 31 16 

February 1997 -21 28 3 

March 1997 -20 28 1 

April 1997 -13 16 – 

October 1997 -11 8 – 

November 1997 -20 26 2 

December 1997 -21 30 1 

January 1998 -31 31 8 

February 1998 -14 18 – 

March 1998 -17 24 – 

April 1998 -2 3 – 

*From Climatological Data. Minneapolis, MN, National Oceanic and Atmospheric 

Administration, www.noaa.gov.

4 
5 

Table 2. Summary of Minnesota sections and PCC mixtures. 

Mixture 

Number 

Fly Ash 

Content, % 

Fresh Air 

Content, % 

Hardened Air 

Content, % 

(Entrained)* 

28-day Comp. 

Strength, 

megapascals 

(MPa) 

Dynamic 

E, MPa 

MN1** 15 3.9 2.9 30.5 39,000 

MN2 15 2.7 0.9 26.5 39,000 

MN3 15 2.0 0.7 38.5 42,000 

MN4 0 2.5 1.4 36.5 39,000 

MN5 0 1.5 1.7 40.5 42,000 

MN6 30 3.8 1.4 29.0 38,000 

MN7 30 1.4 1.5 26.5 44,000 

MN8*** HCC 5.6 4.4 23.0 27,000 

The Minnesota sections were constructed in October 1992 and first surveyed in October 1994. 

After 2 years of exposure, the test sections appeared just like new. Even the section with low air 

content and no fly ash (MN4 and MN5) showed no signs of freeze-thaw distress (no D-cracking, 

scaling, or popouts). The only minor distress present was some loss of fines from surface (not 

extensive enough to be called scaling) and a marred surface on sections MN6 and MN7, which 

appeared to be construction related as shown in figure 1. Most of the sections also had occasional 

minor joint spalling, which again appears to be construction related (i.e., sawing damage). Photos 

of each section in 1994 are provided in appendix A. 

CONDITION SURVEYS OF MINNESOTA SECTIONS, 1994 THROUGH 1998 

Additional data on the mixtures are given in tables 3 and 4. 

***Proprietary high-carbon concrete admixture. 

*From Resistance of Concrete to Freezing and Thawing, SHRP-C-391, Transportation 

Research Board. 

**Minnesota Department of Transportation (MnDOT) Standard, except for air content. 

Figure 1. Test panels for mixture MN7 showing cores taken in 1994. 
Table 3. Summary of laboratory durability test results from the Minnesota site—air entrain

Air Void/Water Pore System Characteristics

Mixture Description 

Fresh 

Air 

(FA) 

(%) 

Hardened

Air 

(%) 

Hardened

Air 

(ent, %) 

Spacing 

Factor 

(mm)* 

Spacing 

Factor 

(ent, 

mm) 

Specific 

Surface 

(mm-1) 

Specific 

Surface 

(ent, mm1) 

Voids/

mm 

Voids/

mm 

(ent) 

Avg. Ch.

Length 

(mm) 

Avg

Le

(ent

MN1 MnDOT standard 3.9 3.5 2.9 0.249 0.228 24.5 29.0 0.216 0.213 0.163 0.MN2 

MN1 w/marginal air 

2.7 1.2 0.9 0.353 0.306 28.0 36.2 0.080 0.079 0.143 0.

MN3 MN1 w/low air 2.0 1.0 0.7 0.907 0.780 11.3 15.3 0.029 0.027 0.353 0.MN4 

MN1 w/marginal air, no FA 

2.5 1.7 1.4 0.377 0.344 21.8 26.1 0.094 0.092 0.183 0.

MN5 MN1 w/low air, no FA 1.5 2.2 1.7 0.378 0.336 19.4 24.7 0.109 0.105 0.206 0.

6 

MN6 

MN1 w/marginal air, 30% FA 

3.8 1.6 1.4 0.277 0.261 31.2 35.0 0.128 0.126 0.128 0.

MN7 MN1 w/low air, 30% FA 1.4 2.7 1.5 0.390 0.304 17.6 28.9 0.116 0.108 0.228 0.MN8 

MnDOT experimental mixture 

5.6 7.3 4.4 0.215 0.166 20.7 33.9 0.379 0.370 0.190 0.

*mm—millimeters Note 1: All specimens cured 28 days (including 27 days in lime water). Note 2: All air void measurements performed at Michigan State University.
Table 4. Summary of laboratory durability test results from the Minnesota site—freeze-thaw 

Cycles to Cycles to % Mass Loss @ 

Durability 

Factor 60% RDM* 0.1% Dilation 60% RDM or 300 Cycle 

Mixture Description 

Mean Std. Dev. Mean Std. Dev. Mean Std. Dev. Mean Std. Dev. 

MN1 MnDOT standard 98.9 0.4 300+ – 300+ – 0.1001 0.0066 MN2 MN1 w/marginal air 98.4 0.6 300+ – 300+ – 0.1028 0.0206 MN3 MN1 w/low air 97.6 1.1 300+ – 300+ – 0.1185 0.0083 MN4 MN1 w/marginal air, no FA 97.9 0.3 300+ – 300+ – 0.0989 0.0205 MN5 MN1 w/low air, no FA 92.5 3.2 300+ – 300+ – 0.0460 0.0084 MN6 MN1 w/marg. air, 30% FA 99.2 0.5 300+ – 300+ – 0.1054 0.0123 MN7 MN1 w/low air 30% FA 91.4 6.5 300+ – 300+ – 0.0731 0.0154 MN8 MnDOT experimental mixture 98.4 0.3 300+ – 300+ – 0.0467 0.0506 

Note 1: All specimens cured 28 days (27 days in lime water). Note 2: All frost-resistance testing conducted in accordance with the American Association of State Highway Transportation Officials (AASHTO) T161 (American Society for Testing and Materials (ASTM) C 666) Procedure B, modified (use of cloth wrapRDM = Minnesota Road Design Manual 

7 
These sections were visually surveyed again in September 1995. There were virtually no 

observable changes in condition from 1994 other than the appearance of two popouts, one in 

MN3 and one in MN4. Both these sections have low air content, but the popouts are very minor. 

No signs of scaling or other deterioration were observed. One other change of note is the dense 

encroachment of vegetation all around the test pads. 

Subsequent visual surveys of all test sections were conducted in 1996, 1997, and 1998. Very 

little deterioration occurred over this time period. The results of the final survey in 1998 are 

summarized as follows: 

Section 1—15 percent fly ash, 3.9 percent air content—Very light surface scaling (visible 

sand particles are about 0.2 mm diameter) over the whole surface. See figure 2 for 1998 

photograph of section 1. 

Figure 2. Photograph of Minnesota test section 1 (1998). Most of 

the surface texture (brooming) is still visible. Sand particles up to 

2 mm are visible in a very lightly scaled surface. 

Section 2—15 percent fly ash, 2.7 percent air content—Same visual condition as section 1. 

Section 3—15 percent fly ash, 2.0 percent air content—Similar very light surface scaling as 

sections 1 and 2, with a band about 400-500 mm wide in the direction of brooming having 

visibly less scaling. 

Section 4—No fly ash, 2.5 percent air content—Similar very light scaling, with a band about 

600 mm wide having less scaling. 

Section 5—No fly ash, 1.5 percent air content—Light scaling, with enough scaling in a few 

places to obscure the brooming marks. See figure 3 for photograph of section 5 in 1998. 

8 
Figure 3. Photograph of Minnesota test section 5 (1998). 

Scaling is slightly heavier than figure 2, and in some areas 

the surface texture (brooming) is obscured. 

Section 6—30 percent fly ash, 3.8 percent air content—Scaling is generally very light, but 

about 5-10 percent of the total section area is scaled enough to obscure the brooming marks. The 

visible sand particles in these areas are in the 0.5-2 mm size range. 

Section 7—30 percent fly ash, 1.4 percent air content—Light scaling over entire area. Streaks 

of scaling heavy enough to obscure broom marks are present throughout the section to a total of 

about 20 percent of the section area; these are generally adjacent to areas showing excessive 

paste (possibly an artifact of plastic placed on the concrete for curing before the concrete was 

initially set). 

Section 8—High-carbon concrete (MnDOT experimental), 5.6 percent air content—Very 

light scaling throughout the section, with a few small streaks of unscaled concrete and also a few 

streaks of slightly heavier scaling. 

It is important to note that none of these sections received any traffic loadings or de-icing salts 

over the 6-year period. The lack of de-icing salts may be of particular impact, as nearly all 

highways in freeze areas received large amounts, and this has been shown to have a very large 

effect on freeze-thaw scaling. (Okamoto et al., 1993) 

TESTING OF CORES FROM MINNESOTA SECTIONS, 1994 TO 1998 

Since the initial monitoring in 1994, two cores have been taken every year from each test section 

for the purpose of measuring their dynamic modulus. These cores were generally taken away 

from the joints and are not representative of concrete near the joints. The cores were dried at 

approximately 50 percent relative humidity and 22 °C to constant mass and were tested in 

accordance with ASTM C 215 to determine the dynamic modulus of elasticity. The results are 

summarized in table 5. There does not appear to be any significant change in the condition of the 

9 
interior concrete as measured by changes in core stiffness. This would suggest that there has not 

been any internal deterioration in the concrete from construction to 1998 despite the harsh winter 

conditions at this Minnesota site. It is not known what damage existed near the joints where 

more water could saturate the concrete. 

Table 5. Dynamic modulus of Minnesota cores. 

SHRP Core Dynamic Modulus, MPa 

C-203 1994 1995 1996 1997 Designation 1998 

MN1 38,829 36,274 38,125 38,601 38,453 

MN2 39,248 39,229 40,411 39,630 38,317 

MN3 42,286 40,652 41,676 41,740 41,902 

MN4 38,710 39,201 38,088 40,689 38,741 

MN5 41,745 40,513 41,289 40,127 41,410 

MN6 38,363 40,473 40,602 40,027 40,941 

MN7 44,231 44,038 44,879 44,283 47,191 

MN8 27,519 27,376 28,435 29,068 28,553 

The Minnesota sections are exposed to environmental effects only, and they do not show any 

significant degradation in condition. Minor scaling was visible on most of the slabs, consisting 

mostly of loss of fines from the surface. The level of scaling was similar in most sections, but at 

least two sections seemed to exhibit somewhat noticeable differences in condition. Section 8, 

which is the MnDOT experimental mix that had the highest fresh air content (5.6 percent), did 

not show any signs of scaling. Section 5 appeared to have slightly more scaling than other 

sections. Section 5 contains only 1.5 percent air and no fly ash. The field observations were 

generally consistent with what may be expected based on mix design, but section 7, which had 

the lowest fresh air content (1.4 percent), had very little scaling. Section 7, however, did contain 

twice the amount of fly ash provided in the control mix (30 percent). 

FOLLOWUP FREEZE-THAW TESTING OF SPECIMENS FROM MINNESOTA 

SECTIONS 

Cores were taken from Minnesota test panels MN1, MN2, and MN3. The cores were allowed to 

air dry for 8 months and were then cut into freeze-thaw test specimens. The specimens were 

soaked in calcium-saturated water for 7 days and then tested in rapid freezing and thawing 

(AASHTO T161, Procedure C). Results of the freeze-thaw tests are presented in table 6, along 

with the original freeze-thaw results (from specimens prepared during test section construction) 

and the air-void parameters measured at the time of construction. 

Table 6. Results of followup freeze-thaw testing of Minnesota sections.

Mixture Plastic 

Air % 

Hardened 

Air % 

Specific 

Surface 

mm2/mm3

Spacing 

Factor 

mm 

Original 

Durability 

Factor 

Followup 

Durability 

Factor 

MN1 3.9 3.5 24.5 0.249 99 100

MN2 2.7 1.2 28.0 0.353 98 39

MN3 2.0 1.0 11.3 0.907 98 16

10 
CHAPTER 3. OHIO TEST SECTIONS 

OHIO WINTER WEATHER CONDITIONS 

A summary of climatic exposure conditions for the Ohio sections is given in table 7. These 

sections were subjected to severe winter freezing and thawing temperatures. The number of air 

freeze-thaw cycles is about 110 per year (less than Minnesota, with about 160 per year). 

DESCRIPTION OF THE OHIO EARLY-STRENGTH FREEZE-THAW AND DCRACKING MITIGATION EXPERIMENTAL SECTIONS 

The purpose of this experiment was to investigate the effect of the entrained air-void system on 

resistance to freezing and thawing. The Ohio sections consist of 10 lane-width 1.8-m full-depth 

repairs placed on State Route 2 in an old D-cracked jointed concrete pavement. Six different 

early-strength mixtures (designated PC, RSC, HES, VES, FT, and ODOT) were placed to 

determine whether these mixtures had different resistance to freezing and thawing than 

conventional mixtures. One of the mixtures was placed in six replicates (standard mixture, with 

replicates I1 through I5 having different air contents than the standard ODOT mixture) with 

varying air contents to examine the effects of air-void parameters on frost resistance. 

These sections were placed during the summer of 1992 and were first monitored for evidence of 

deterioration from freezing and thawing in November of 1994. The sections were part of the 

trafficked pavement, and de-icing salt was applied when necessary. Snow was removed from the 

sections as a part of normal highway maintenance. However, the test section in Ohio was 

diamond-ground between construction in 1992 and the first monitoring visit in 1994. This 

removed the original surface texture, making the quantification of scaling almost impossible. 

Laboratory data from these sections are given in tables 8 and 9. 

The experiment at the Ohio site also included the evaluation of the effectiveness of various types 

of sealers in mitigating D-cracking in the old adjacent concrete slabs. The saw-cut face of the 

original pavement exposed by the removal of the concrete in the repair area was cleaned and 

treated with four different types of sealers prior to the placement of the repair concrete for this 

experiment. The sealers and control joints included the following: 

• A penetrating oil sealer (LS). 

• A water-based silane sealer (WS). 

• A solvent-based silane sealer (SS). 

• A two-part urethane sealer (2P). 

• Control joints with no sealer treatment (N). 

Twenty joint repairs were made at the Ohio site, providing 40 joint faces in the original concrete 

and as indicated, control joints were left with no sealer treatment. 

11 
12 

Table 7. Summary of winter weather conditions, Ohio sections. 

Month/Year Monthly Low 

Temperature, °C 

Days Below 

0 °C 

Days Below 

–18 °C 

October 1992 -3 6 –

November 1992 -7 10 –

December 1992 -9 22 –

January 1993 -13 26 –

February 1993 -21 28 4 

March 1993 -16 18 –

October 1993 -1 2 –

November 1993 -6 12 –

December 1993 -18 21 1 

January 1994 -28 30 8 

February 1994 -20 25 1 

March 1994 -10 22 –

October 1994 1 – –

November 1994 -7 9 –

December 1994 -10 20 –

January 1995 -16 25 –

February 1995 -18 25 1 

March 1995 -13 17 –

October 1995 1 – –

November 1995 -6 19 –

December 1995 -16 29 –

January 1996 -18 28 1 

February 1996 -23 20 4 

March 1996 -14 29 –

October 1996 0 1 –

November 1996 -10 20 –

December 1996 -13 20 –

January 1997 -20 27 3 

February 1997 -13 22 –

March 1997 -8 22 –

October 1997 0 1 –

November 1997 -8 14 –

December 1997 -11 24 –

January 1998 -11 23 –

February 1998 -7 15 –

March 1998 -8 20 –

*From Climatological Data. Cleveland, OH, National Oceanic and Atmospheric 

Administration, www.noaa.gov.
Table 8. Summary of laboratory durability test results on Ohio test sections—air entrainm

Air Void/Water Pore System Characteristics

Mixture Description 

Fresh 

Air 

(%) 

Hardened 

Air 

(%) 

Hardened 

Air 

(ent, %) 

Spacing 

Factor 

(mm) 

Spacing 

Factor 

(ent, 

mm) 

Specific 

Surface 

(mm-1) 

Specific 

Surface 

(ent, mm-1) 

Voids/

mm 

Voids/ 

mm (ent) 

L

H1 ODOT Class FS (morning) 3.8 4.9 2.6 0.246 0.179 24.2 44.2 0.298 0.286 H1 

ODOT Class FS (morning, 14-day) 

4.5 3.4 2.4 0.222 0.187 30.8 42.4 0.260 0.250 

H2 ODOT Class FS (afternoon) 6.5 4.7 2.6 0.350 0.360 25.2 43.5 0.296 0.287 I1 H1 w/0.8*A/E dosage 7.0 4.1 2.8 0.157 0.128 42.1 61.0 0.431 0.425 I2 H1 w/0.6*A/E dosage 5.6 4.4 3.0 0.176 0.147 36.1 50.6 0.393 0.386 

13

I3 H1 w/0.4*A/E dosage 6.2 4.1 2.6 0.470 0.387 14.0 20.7 0.143 0.135 I4 H1 w/0.2*A/E dosage 5.8 5.2 4.5 0.213 0.200 27.7 31.3 0.359 0.355 I5 H1 w/0.05*A/E dosage 3.1 2.7 1.8 0.382 0.318 20.2 28.8 0.138 0.132 Note 1: All specimens cured 28 days (including 27 days in lime water) unless noted otherwise. Note 2: All air void measurements for 14-day cures performed at the University of Washington. Note 3: All air void measurements for 28-day cures performed at Michigan State University. Note 4: Compression tests not performed on day 14. Note 5: RSC2 data obtained from contractor’s report; separate traverse not conducted for this project. Note 6: 28-day Pyrament® #1 linear traverse data not available. 
Table 9. Summary of laboratory durability test results on Ohio test sections—freeze-thaw t

Durability Test Results

Durability 

Factor 

Cycles to 

60% RDM 

Cycles to 

0.1% Dilation

% Mass Loss @

60% RDM or 

300 Cycles 

Mix Description 

Mean Std. Dev. Mean Std. Dev. Mean Std. Dev. Mean Std. Dev. 

H1 ODOT Class FS (morning) 17.2 1.7 87 6.2 72 2.1 -0.72 0.01 H1 ODOT Class FS (morning, 14-day) 13.0 0.6 65 2.9 62 8.1 -0.86 0.11 H2 ODOT Class FS (afternoon) 18.5 0.5 92 2.5 73 3.0 -0.51 0.01 I1 H1 w/0.8*A/E dosage 18.8 1.0 95 5.3 82 8.2 -0.32 0.07 I2 H1 w/0.6*A/E dosage 14.0 0.8 71 3.3 66 4.1 -0.83 0.05 I3 H1 w/0.4*A/E dosage 17.6 2.4 89 10.4 75 6.1 -0.87 0.05 I4 H1 w/0.2*A/E dosage 12.8 0.4 64 0.7 56 1.0 -0.90 0.04 I5 H1 w/0.05*A/E dosage 7.75 0.4 41 2.3 33 0.9 -0.69 0.03 Note 1: All specimens cured 28 days unless noted otherwise. Note 2: All frost resistance testing was accomplished in accordance with AASHTO T161 (ASTM C 666) Profor use of cloth wraps and cure periods noted. Note 3: All frost-resistance testing for 14-day cures performed at the University of Washington. Note 4: All frost-resistance testing for 28-day cures performed at Michigan State University.

14 
CONDITION SURVEY OF OHIO SECTIONS, 1994 THROUGH 1998 

The Ohio sections were constructed in September 1992 and first surveyed in November 1994. As 

previously stated, all of these test sections were diamond-ground between 1992 and 1994, which 

made it impossible to observe scaling in the original surface. However, it was possible to observe 

the ground surface for deterioration. No evidence of surface scaling or other deterioration has 

been seen on the diamond-ground surface over the monitoring period. 

All patches in the Ohio section developed a longitudinal crack shortly after construction (within 

2 months). High temperature gradients that developed in the repairs during curing are thought to 

be responsible for the longitudinal cracking. One repair in the FS section also developed a 

transverse crack. 

However, other than these cracks, in 1994 the Ohio sections were distress free. No signs of 

scaling or D-cracking were present on either the repair concrete or the surrounding concrete. 

Faulting and cracking were very low. Results from the 1994 survey are given in tables 10 and 11. 

Table 10. Distress summary of Ohio sections. 

ERES Repair Longitudinal Transverse 

ID Type Station SHRP 1994 1995 1996 1997 1998 SHRP 1994 1995 1996 1997 1998

FS—3 to 8 hr 

H-2 FS 152+53 L L L LLL L LLL H

H-3 FS 151+11 L L L LLL

H-4 FS 149+48 L L L LLL

H-5 FS 148+66 L L L LLL

H-6 FS 147+57 L L L LLL

H-7 FS 147+03 L L L LLL

H-8 FS 146+68 L L L LLL

H-9 FS 145+04 L L L LLL

H-10 FS 144+25 L L L LLL L

Percent Slabs Cracked 100 100 100 100 100 100 0 11 11 11 11 22

FS—Freeze-Thaw 

I-1 I-3 152+14 L L L LLL L LLL L

I-2 I-4 150+76 L L L LLL

I-3 I-5 150+28 L L L LLL

I-4 I-1 149+97 L L L LLL

I-5 I-5 149+14 L L L LLL

I-6 I-2 147+82 L L L LLL

I-7 I-3 147+43 L L L LLL

I-8 I-4 147+17 L L L LLL

I-9 I-2 145+04 L L L LLL

I-10 I-1 144+64 L L L LLL

Percent Slabs Cracked 100 100 100 100 100 100 0 10 10 10 10 10

15 
Table 11. Faulting summary of Ohio sections. 

Faulting

ERES 

ID

Repair 

Type

Approach Joint Leave 

Station 1994 1995 1996 1997 1998 1994 1995 1996 1997 1998

FS—3 to 8 hr 

H-2 FS 152+53 0.01 0.00 0.01 0.02 n/a 0.06 0.02 0.05 0.06 n/a

H-3 FS 151+11 0.05 0.03 0.02 0.03 0.01 0.11 0.07 0.10 0.05 0.07

H-4 FS 149+48 0.04 0.02 0.04 0.01 n/a 0.06 0.04 0.03 0.04 0.00

H-5 FS 148+66 0.04 0.02 0.01 0.01 n/a 0.00 0.00 0.01 -0.01 0.00

H-6 FS 147+57 0.02 0.00 0.00 0.00 0.03 0.05 0.00 0.01 0.02 0.04

H-7 FS 147+03 0.02 0.00 0.00 -0.01 -0.01 0.00 -0.01 -0.01 0.00 -0.01

H-8 FS 146+68 0.01 0.00 0.02 -0.02 0.10 0.04 0.03 0.08 0.07 0.07

H-9 FS 145+04 0.00 0.02 -0.01 -0.02 0.01 0.04 0.00 -0.01 0.02 0.00

H-10 FS 144+25 0.05 0.04 0.03 n/a n/a 0.04 0.03 0.01 0.02 n/a

Average 0.03 0.01 0.01 0.00 0.03 0.04 0.02 0.03 0.03 0.02

FS—Freeze-Thaw 

I-1 I-3 152+14 0.03 -0.01 0.00 0.03 0.01 0.01 0.01 0.03 0.03 -0.01

I-2 I-4 150+76 0.03 0.03 0.03 0.01 0.02 0.02 -0.02 -0.01 -0.02 -0.04

I-3 I-5 150+28 -0.02 0.00 0.00 0.00 -0.01 0.05 0.05 0.04 0.04 0.05

I-4 I-1 149+97 0.02 0.01 0.03 -0.01 -0.02 0.02 -0.03 -0.03 0.00 0.02

I-5 I-5 149+14 0.00 0.00 0.01 0.0 0.0 0.0 -0.01 0.01 -0.01 0.00

I-6 I-2 147+82 0.04 0.03 0.03 0.0 0.0 0.0 0.0 0.05 0.03 0.03

I-7 I-3 147+43 0.00 -0.01 -0.02 -0.02 0.0 -0.01 -0.02 -0.01 -0.03 n/a

I-8 I-4 147+17 0.02 0.00 0.03 0.0 0.0 0.0 -0.02 0.00 -0.03 -0.03

I-9 I-2 145+04 0.03 -0.02 -0.01 0.0 0.0 0.0 -0.01 -0.01 0.00 -0.01

I-10 I-1 144+64 0.01 0.02 -0.02 n/a n/a -0.01 -0.02 -0.02 -0.06 -0.06

Average 0.02 0.01 0.01 0.00 0.01 0.01 -0.01 0.0 -0.01 -0.01

The Ohio sections were surveyed again in November 1995. There were no significant changes in 

condition from 1994. No new distresses developed, and faulting remained about the same level. 

Some faulting values actually decreased. The decreased faulting is most likely due to 

measurement variability, but moisture and temperature conditions can also affect faulting 

measurements. Again, no signs of scaling or D-cracking were observed. 

The patches were examined annually from 1994 through 1998. No additional surface defects 

were noted in any of the patches from 1994 through 1996. In 1997, surface map-pattern cracking 

was noted in varying degrees (see figure 4). The cracking was generally worse in the wheelpath 

near the transverse joints between the patches and the original pavement (figure 5). By 1998, the 

severity of the cracking had increased; some patches had been repaired with asphalt concrete 

where the deterioration had produced potholes. 

Samples were taken from portions of the patches, and microscopic examination of the samples 

indicated that both cracks and air voids in the concrete were filled with ettringite. 

The entrained air-void system appears to have had no effect on the deterioration of the repairs 

with the diamond ground surface (Stark et al., 1998, and Heinz et al., 1989). 

16 
Figure 4. Surface cracking in patch, mixture I3 

(parallel lines on surface are the result of 

surface diamond grinding soon after construction). 

Figure 5. Deterioration in patch (left) in wheelpath, mixture 

I4 (surface has been diamond ground, and note longitudinal 

paint strip along pavement edge at bottom of photo). 

17 
TESTING OF CORES FROM OHIO SECTIONS, 1994 TO 1998 

Cores were taken from the Ohio test sections between 1994 and 1998 for dynamic modulus 

testing. The cores were dried at approximately 50-percent relative humidity and 22 °C to 

constant mass and were tested in accordance with ASTM C 215 to determine the dynamic 

modulus of elasticity. The results are summarized in table 12, along with strengths and stiffness 

determined as parts of the SHRP C-203 and C-206 projects. 

Table 12. Ohio early-strength sections.

SHRP Core Dynamic Modulus, MPa 

C-203 

Designation 

Strength 

28-day 

lab, MPa 

SHRP 

2-month 

Strength

C-206 

Cores, MPa

Stiffness 1994 1995 1996 1997 1998 

PC1 58.9 43.9 26,546 – 27,125 – – 27,608

PC2 50.5 55.4 24,822 29,631 26,876 26,699 – 25,340

RSC1 – 41.4 21,030 – 30,968 – – – 

RSC2 – 38.7 20,685 29,482 30,834 33,218 – 24,657

HES 43.3 42.0 19,306 – 22,899 – – 23,600

VES 37.3 38.6 26,546 16,937 18,826 17,832 – 20,131

FT1 – 39.4 19,996 – 25,249 – – 28,281

ODOT 50.6 51.9 21,719 – – 18,433 – 21,748

I1 44.6 – – – 20,601 – – – 

I3 48.3 – – – 18,217 21,139 – 27,773

I4 50.2 – – – 20,164 22,160 – 24,907

I2 50.7 – – – 22,281 – – – 

I5 57.7 – – – 22,661 27,647 – 28,925

With the exception of the VES and RSC2 mixtures, the core stiffnesses do not suggest any 

significant evidence of internal deterioration. The change in dynamic modulus of the VES 

section between the SHRP C-206 2-month followup coring and the 1994-98 coring indicates that 

this mixture may have suffered some internal deterioration, but the relatively constant stiffness 

from 1994-98 suggests that the deterioration is not continuing. The drop in stiffness in 1998 for 

the RSC2 core may not be significant, as there was no other evidence of deterioration in this 

section. Additional coring would be required to verify whether this drop is significant or just 

sampling variability. 

OHIO D-CRACKING MITIGATION SECTIONS 

The original Ohio pavement on which the test sections were installed was constructed with 

D-cracking susceptible aggregate. In an effort to determine whether the existing D-cracking 

could be mitigated, the D-cracked concrete near each of the joints was removed and replaced 

with a full-depth patch. Prior to placing the patches, the sawn faces of the existing concrete were 

treated with one of four sealers (or none for control) in an attempt to prevent the lateral 

movement of water from the transverse joint into the pavement. It was believed that this might 

prevent or at least delay the continuation of the D-cracking. The treatments consisted of either: 

(1) a penetrating oil sealer (LS), (2) a water-based silane sealer (WS), (3) a solvent-based silane 

sealer (SS), or 4) a two-part urethane sealer (2P). Control sections were also left with no sealer 

18 
treatment (N). Table 13 summarizes the sealer treatments along with the subbase type (asphalttreated base (ATB) or granular) and the maximum aggregate size in the existing pavement. 

Table 13. Ohio D-cracking mitigation sections. 

Station 

No. 

Aggregate

Size 

Base 

Type

Patch 

No.

Edge 

Treatment

152+94 25 mm ATB None 

152+94 25 mm ATB H-1 SS 

152+53 25 mm ATB WS 

152+53 25 mm ATB H-2 LS 

152+14 25 mm ATB I-1 2P 

152+14 25 mm ATB (I3) None 

151+11 25 mm ATB None 

151+11 25 mm ATB H-3 WS 

150+76 25 mm ATB I-2 SS 

150+76 25 mm ATB (I4) 2P 

150+28 19 mm crushed I-3 LS 

150+28 19 mm stone (I5) None 

149+97 19 mm crushed I-4 SS 

149+97 19 mm stone (I1) WS 

149+48 19 mm crushed LS 

149+48 19 mm stone H-4 2P 

149+14 19 mm crushed I-5 None 

149+14 19 mm stone (I5) LS 

148+66 19 mm crushed 2P 

148+66 19 mm stone H-5 None 

147+82 19 mm crushed I-6 WS 

147+82 12 mm stone (I2) SS 

147+57 12 mm crushed None 

147+57 12 mm stone H-6 LS 

147+43 12 mm crushed I-7 LS 

147+43 12 mm stone (I3) WS 

147+17 12 mm crushed I-8 None 

147+17 12 mm stone (I4) None 

147+03 12 mm crushed WS 

147+03 12 mm stone H-7 SS 

146+68 12 mm crushed SS 

146+68 12 mm stone H-8 2P 

145+97 12 mm crushed I-9 2P 

145+97 12 mm stone (I2) None 

145+04 25 mm crushed WS 

145+04 25 mm stone H-9 2P 

144+64 25 mm crushed I-10 2P 

144+64 25 mm stone (I1) None 

144+25 25 mm crushed None 

144+25 25 mm stone H-10 WS 

19 
Cores have been taken periodically from selected sections of the D-cracking mitigation test 

section. The cores were identified by the station of the original joint (prior to full- depth 

patching) along with an indication of whether the core was from the approach side of the patch 

or the leave side. The cores were dried at approximately 50-percent relative humidity and 22 °C 

to constant mass and were tested in accordance with ASTM C 215 to determine the dynamic 

modulus of elasticity. 

Nondestructive testing of the existing concrete was conducted adjacent to the treated (or 

untreated) joints using Spectral Analysis of Surface Wave (SASW) methods. This testing was 

used to determine the average velocity of shear wave propagation in the concrete (Vokes et al., 

1997). Because the equipment used to make these measurements in 1994 had an inadequate 

sampling rate to permit reliable separation of the measured vibrations from background noise, 

equipment with a higher sampling rate was used for the 1995 through 1998 measurements. These 

results, along with the dynamic modulus values determined from the cores, are shown in table 

14. 

As of 1998, the core dynamic modulus values do not show any conclusive trends. D-cracking 

would be expected to appear first at the intersection of the transverse and lane-shoulder joints. 

Equipment limitations with the core rig used prevented the cores from being taken exactly at the 

lane-shoulder joints, and because the cores could not be taken close to the lane-shoulder joints, 

this area may not show D-cracking-related deterioration for a number of years. 

However, an examination of the concrete velocity measurements indicates that many sections 

have some degree of deterioration. Direct comparisons of the velocity values from year to year 

cannot be made, probably because temperature effects could not be taken into account (pavement 

temperature measurements at either the surface or at depth were not part of the scope of work). 

By normalizing the data to the approximate maximum value recorded each year (assuming the 

maximum values represent non-deteriorated concrete), the values can be compared. Figure 6 

shows the concrete velocities for each test joint for all 4 years of testing. Visual examination 

during 1997 and 1998 indicated cracking near the transverse joints, which appeared to be Dcracking. These joints are marked with a "D" in figure 6. Also, in 1998 tests could not be 

conducted at some of the transverse joint locations because the concrete near the joints was 

missing right adjacent to the joint or had been patched. These are marked with a "P" in figure 6. 

Tests were conducted (and test values are plotted in figure 6) for these locations, but the actual 

testing location was a few inches (depending upon the extent of the patching or damaged 

concrete) further back from the original joint location. Since D-cracking severity decreases with 

increasing distance from the joint, these test results labeled “P” can be expected to be higher than 

they would have been if the test could have been conducted right at the joint. 

20 
Table 14. Summary of Ohio core dynamic modulus 

and field nondestructive testing (NDT). 

Core Dynamic Modulus, MPa NDT Velocity, m/s Station No. 1994 1995 1996 1997 1998 1995 1996 1997 1998 

152+94 33,700 33,914 2,310 1,950 1,950 2,500

152+94 33,000 30,662 1,810 1,915 1,550 2,050

152+53 34,188 2,280 1,895 1,900 2,500

152+53 2,625 2,200 1,600 2,050

152+14 2,375 1,895 1,850 1,850

152+14 2,750 2,470 2,400 2,500

151+11 2,125 1,940 2,000 2,500

151+11 36,000 2,670 1,930 2,300 2,450

150+76 34,143 2,655 2,440 2,500 2,100

150+76 36,600 2,655 2,470 2,450 2,450

150+28 33,697 34,128 2,690 1,890 1,950 2,550

150+28 34,709 34,637 2,470 2,000 1,950 2,450

149+97 29,500 35,919 2,310 1,940 2,450 2,550

149+97 29,600 2,780 2,470 2,550 2,600

149+48 32,500 2,625 1,870 2,400 2,600

149+48 33,200 36,900 2,655 2,440 2,450 2,550

149+14 32,900 35,100 2,375 2,375 2,400 2,450

149+14 32,972 2,440 2,410 2,350 2,500

148+66 2,430 2,375 2,600 2,050

148+66 2,500 2,440 2,550 2,700

147+82 32,322 2,375 2,500 2,300 2,550

147+82 25,700 30,243 2,470 2,470 2,400 2,000

147+57 32,028 2,440 1,875 2,300 2,050

147+57 30,635 2,280 1,920 1,950 1,300

147+43 25,851 2,340 2,345 2,350 2,450

147+43 30,857 2,250 2,440 2,450 2,550

147+17 28,912 30,913 2,375 2,390 2,300 2,500

147+17 29,800 34,000 2,405 2,440 2,350 2,000

147+03 2,060 2,345 2,300 2,450

147+03 31,879 2,470 1,690 1,950 2,500

146+68 31,600 30,600 2,250 1,970 2,450 2,450

146+68 28,500 34,600 2,400 1,970 2,350 2,550

145+97 33,740 2,390 1,970 2,400 2,500

145+97 2,340 2,030 2,250 2,550

145+04 2,390 2,000 2,200 2,450

145+04 35,283 2,090 1,875 2,300 2,100

144+64 35,415 2,375 2,280 1,800 2,050

144+64 2,375 1,940 1,900 2,200

144+25 2,200 2,000 2,000 2,550

144+25 22,532 2,410 1,940 2,400 2,600

21 
Figure 6. Field NDT velocity measurements. 

D-CRACKING MITIGATION RESULTS 

D-cracking has reappeared adjacent to some of the patches and can be identified both visually 

and with the NDT velocities (Vokes et al., 1997). Areas with visual D-cracking are identified 

with a “D” in figure 6. D-cracking has reappeared in all of the sections made with aggregate 

having a 25-mm top size, except for three of the sections listed as being on ATB, which may 

reduce the moisture availability from the subbase. This suggests that none of the edge treatments 

was successful in significantly delaying the return of D-cracking. D-cracking has returned to 

some of the sections made with 19-mm aggregate, and the 19-mm sections with no evidence of 

D-cracking include both treated sections and control sections with no treatment. A few of the 12-

mm sections also have D-cracking but, as expected, the smaller aggregate size has reduced the 

D-cracking potential. 

22 
CHAPTER 4. CONCLUSIONS AND RECOMMENDATIONS 

Field test sections were constructed during 1992 as part of the SHRP program investigating the 

frost resistance of concrete. The test sections had three general purposes: 

• Determine whether high-performance concrete (high-performance due to rapid strength gain) 

meeting conventional entrained-air requirements would be frost resistant. 

• Determine whether conventional entrained-air requirements were appropriate for pavement 

concrete. 

• Evaluate a potential method for mitigating existing D-cracking. This report documents the 

results of a 5-year monitoring program conducted for the purpose of evaluating the 

performance of the test sections. 

FREEZE-THAW RESULTS 

The Minnesota sections contained concrete slabs having fresh air contents ranging from 1.4 to 

5.6 percent (hardened entrained air ranged from 0.7 to 4.4 percent). Other than minor surface 

scaling, none of the Minnesota freeze-thaw sections shows any evidence of significant 

deterioration after six Minnesota winters. This is contrary to expectations based on the lack of 

“adequate” entrained air in most of the sections (Snyder and Janssen, 1994). However, these 

results must be tempered with the fact that no de-icing salts were used on these sections since 

they were not trafficked. Also, the monitoring only covered a period of six winter exposures. 

Additional exposure may be necessary to produce measurable damage. A recent survey 

conducted in May 2001 showed some additional scaling and popouts on the sections with a 

lower entrained air content (< 2.5 percent), but the other sections did not show significant further 

deterioration. With de-icing salts, the deterioration is expected to be much greater for the lower 

air content concrete (Janssen and Snyder, 1994). 

Concrete specimens prepared from cores taken from the Minnesota sections after six winters did 

deteriorate in laboratory freeze-thaw testing. These results are in contrast to the results of tests 

conducted when the sections were placed. Table 6 shows that section MN1, with close to the 

recommended maximum spacing factor of 0.20 mm, performed well in the more recent tests, 

while sections MN2 and MN3 performed much more poorly. The spacing factors for MN2 and 

MN3 were much worse than the recommended 0.20 mm; however, all three sections performed 

well in freeze-thaw tests conducted on concrete that had not received any “real” winter exposure. 

This difference in test results may be due to shortcomings in the AASHTO T161 test procedure 

(El-Korchi et al., 1995). 

No significant evidence of frost-related deterioration was identified in the diamond-ground Ohio 

early-strength sections, and these were regularly subjected to de-icing salts. The fresh mix air 

contents ranged from 1.8 to 4.5 percent, and hardened from 1.8 to 3.3. Some of these sections are 

cracking, but the cause does not appear to be frost-related. 

Surface scaling is the most likely form of freeze-thaw deterioration in a concrete pavement. The 

diamond grinding of the Ohio sections prevented the detection of scaling in those early-strength 

23 
patches. Light scaling was seen in the Minnesota sections, but the severity was too low to 

describe it as significant deterioration. 

Because the Minnesota sections did not receive any de-icing salt, it is recommended that portions 

of these sections receive de-icing salt for the next 5 years to determine whether the de-icing salt 

causes significant deterioration. 

D-CRACKING MITIGATION 

The D-cracking mitigation study indicated that in many cases the D-cracking returned after 6 

years, independent of the mitigation technique tried. Whether this is because the edge treatments 

were not effective in preventing the ingress of moisture through the vertical faces is not known. 

Cores should be taken at the treated edges and investigated to determine the effectiveness of the 

aged sealers. 

Additional testing would be required with other materials and existing D-cracked concrete to 

further evaluate the specific mitigation approaches. 

24 
APPENDIX A 

CONDITION SURVEY OF MN/ROAD PCC TEST PADS 

(SHRP C-203 PADS) IN 1994, 1998, AND 2001 

This appendix describes the condition surveys performed in 1998 and 2001 and includes the 

photos that were taken in 1994 and 2001. The condition surveys in 1994 showed no deterioration 

whatsoever. These sections were constructed in 1992, so the 2001 survey represents 9 years of 

service. Note that no de-icing salts were applied to these concrete pads. 

MN1 Section 1—15 percent fly ash, 3.9 percent air content 

1998: Very light surface scaling (visible sand particles are about 0.2 mm diameter) over the 

whole surface. 

2001: Very light loss of surface mortar observed throughout the pad—probably consistent with 

expectations for 9-year-old PCC. There are several skid loader surface scratches present on this 

pad. Three or four small popouts (< 25.4 mm diameter, < 12.7 mm deep) are present, but there is 

no significant scaling or spalling. The surface condition is relatively uniform and the pad is 

generally in excellent condition with respect to durability. 

MN2 Section 2—15 percent fly ash, 2.7 percent air content 

1998: Very light surface scaling (visible sand particles are about 0.2 mm diameter) over the 

whole surface. 

2001: Five or more popouts are visible, mostly small ones, but one is medium-sized (~31.75 mm 

in diameter, 12.7 to 19.05 mm deep). There is one large spall adjacent to a core hole from 

previous test specimen retrieval. There is generally more loss of surface mortar than was 

observed for MN1, and there is a whitish, crystalline-looking deposit in the surface texture of 

some of the areas with mortar loss. Some skid loader damage (surface scratches/gouges) runs in 

the east-west direction. The surface is generally in good condition with respect to durability. 

MN3 Section 3—15 percent fly ash, 2.0 percent air content 

1998: Similar very light surface scaling as sections 1 and 2, with a band about 

400-500 mm wide in the direction of brooming having visibly less scaling. 

2001: A few larger popouts are visible on this pad (~38.1 mm in diameter, 

12.7 to 19.05 mm deep). More loss of surface mortar is observed throughout the pad, especially 

at the east end. The surface color and texture of the pad is less uniform, and the original broomed 

surface texture is difficult to see in some areas of mortar loss. Overall, the surface is in fair to 

good condition. 

MN4 Section 4—No fly ash, 2.5 percent air content 

1998: Similar very light scaling, with a band about 600 mm wide having less scaling. 

25 
2001: There is one large popout (50.8+ mm in diameter, 19 mm deep) near the west end of the 

pad. There is a large spall adjacent to a 101.6-mm core hole at the west end of the slab. There is 

some loss of surface mortar (and evidence of the same whitish crystalline deposits observed in 

MN2), but texture is generally good and uniform throughout. No significant spalling or scaling is 

present. Overall condition is good to very good. 

MN5 Section 5—No fly ash, 1.5 percent air content 

1998: Light scaling, with enough scaling in a few places to obscure the brooming marks. 

2001: There is heavier loss of surface mortar throughout, resulting in localized elimination of the 

broomed surface texture. There is no significant scaling or spalling/fraying of joints. The 

heaviest loss of mortar and texture is along a .3 m to .6 m band along the south edge of the pad, 

which is characterized by a darker color. The whitish crystalline deposits are visible in other 

areas of the pad. There are some skid loader marks oriented in a north-south direction in the 

southwest quarter of the pad. The overall general condition of the pad is considered good. 

MN6 Section 6—30 percent fly ash, 3.8 percent air content 

1998: Scaling is generally very light, but about 5 to 10 percent of the total section area is scaled 

enough to obscure the brooming marks. The visible sand particles in these areas are in the 0.5 

mm to 2 mm size range. 

2001: There is localized heavy loss of mortar and surface discoloration along various lines that 

suggest localized water problems under plastic curing sheets. There is a large spall at the 

southeast corner of the pad. A few small popouts are present throughout the pad. No significant 

spalling or scaling was observed. The pad is in generally good condition with respect to 

durability except for the presence of the locally heavy mortar loss probably associated with the 

plastic curing cover. 

MN7 Section 7—30 percent fly ash, 1.4 percent air content 

1998: Light scaling over entire area. Streaks of scaling heavy enough to obscure broom marks 

are present throughout the section to a total of about 20 percent of the section area; these are 

generally adjacent to areas showing excessive paste (possibly an artifact of plastic placed on the 

concrete for curing before the concrete was initially set). 

2001: There is again heavy mortar loss along various “plastic covering” lines in the east half of 

the pad. The loss is fairly deep (3.18 to 6.35 mm, locally) and the broomed texture is gone in 

these areas. There are also areas of what appear to be coring slurry or grey epoxy on the pad 

surface. A few small popouts are present throughout the slab. There is light fraying (25.4 to 50.8 

mm long, < 12.7 mm wide) at two joint locations. There is a large spall in the southeast corner of 

the pad. Slab texture at the west end of the pad is generally good and uniform (no evidence of 

plastic sheeting problems). 

26 
MN8 Section 8—“High-Carbon Concrete (MnDOT Experimental),” 5.6 percent air content 

1998: Very light scaling throughout the section, with a few small streaks of unscaled concrete 

and also a few streaks of slightly heavier scaling. 

2001: There are skid loader marks/gouges present, many in the northeast and southeast corners 

and one along the south edge of the pad. There are also areas of slurry or gray epoxy on the 

surface in the east third of the pad. There is moderate mortar loss throughout the pad, especially 

in the southwest corner of the pad. There is light fraying along the north-south joint between the 

two panels on the south side of the pad, and one frayed area extends 12.7 to 19 mm from both 

sides of the joint for a distance of about 76.2 mm. A few small popouts are scattered throughout 

the pad. The pad surface is generally in good condition with respect to apparent freeze-thaw 

durability problems. 

Summary 

From 1998 to 2001 there was heavier loss of surface mortar throughout those sections with the 

lowest air content (section 3 with 2 percent; section 5 with 1.5 percent; and section 7 with 1.4 

percent) resulting in localized elimination of the broomed surface texture. More loss of surface 

mortar was observed throughout these pads. However, there was no significant scaling or 

spalling/fraying of joints. 

The MnDOT standard mix (except for lower air), section 1 (3.9 percent air), had only a very light 

loss of surface mortar throughout the pad—probably consistent with expectations for 9-year-old 

PCC. 

Had these sections been subjected to substantial de-icing salts over the past 9 years, it is expected 

that those with the lowest air voids would have shown much greater surface deterioration. 

Note that some of the photos taken in May 2001 could not be taken of the center joint because 

MnDOT maintenance was storing materials on the pads. 

27 
Figure A1. Section MN1—1994. 

Figure A2. Section MN1—May 2001. 

28 
Figure A3. Section MN2—1994. 

Figure A4. Section MN2—May 2001. 

29 
Figure A5. Section MN3—1994. 

Figure A6. Section MN3—May 2001. 

30 
Figure A7. Section MN4—1994. 

Figure A8. Section MN4—May 2001. 

31 
Figure A9. Section MN5—1994. 

Figure A10. Section MN5—May 2001. 

32 
Figure A11. Section MN6—1994. 

Figure A12. Section MN6—May 2001. 

33 
Figure A13. Section MN7—1994. 

Figure A14. Section MN7—May 2001. 

34 
Figure A15. Section MN8—1994. 

Figure A16. Section MN8—May 2001. 

35 

APPENDIX B 

INFORMATION AND PHOTOS ON 

OHIO FREEZE-THAW FULL-DEPTH REPAIRS 

The test sections in Ohio were diamond ground between construction and the first monitoring 

visit (figure B1), so no evidence of surface scaling was visible. However, the diamond-ground 

surface did not experience any deterioration. 

Figure B1. Typical surface textures after 

diamond grinding, Ohio test sections. 

Nondestructive testing of the existing D-cracking susceptible concrete was conducted adjacent to 

the treated (or untreated) joints using Spectral Analysis of Surface Wave (SASW) methods. A 

schematic of the SASW test method is shown in figure B2. Actual testing at the Ohio test 

sections is shown in figure B3. 

Figure B2. Schematic diagram of SASW testing (from Malhorta and Carino, 

Handbook on Nondestructive Testing on Concrete, CRC Press, New York, 1991.) 

37 
Figure B3. SASW testing at the Ohio test sections. 

The method involved impacting the surface of concrete in such a way as to maximize the 

production of surface waves (R-waves) while minimizing the compression waves (P-waves). 

Two accelerometers mounted in line about 75 mm from the joint were used to measure the Rwave vibrations. Analysis of the phase shift of the vibrations between the two accelerometers 

was used to determine the R-wave velocity for various vibration frequencies. High-frequency 

vibrations are representative of shallow depths, while lower frequencies are more influenced by 

materials at greater depths in the pavement. 

Figure B4 shows a typical R-wave velocity versus vibration frequency plot. The concrete 

pavement and subbase (base) portion are easily identified. The central section of the graph is 

dominated by noise resulting from waves reflected by the vertical edge of the pavement. This 

phenomenon is present in most of the R-wave velocity versus vibration frequency plots from the 

Ohio testing. Extensive analysis was conducted to filter out this reflection noise from the digital 

data obtained in Ohio. 

38 
Figure B4. Typical R-wave velocity versus vibration frequency plot. 

39 

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Annual Book of ASTM Standards, Vol. 04.02, Concretes and Aggregates, American Society for 

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El-Korchi, T, M. Simon, and S. Forster, “Assessing freezing and thawing resistance of concrete 

using the modified AASHTO T161 (ASTM C 666) procedure,” Concrete Under Severe 

Conditions: Environment and Loading, Vol. 1, edited by K. Sakai, N. Banthia, and O.E. Gjørv, 

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Heinz, D, U. Ludwig and I. Rüdiger, “Delayed ettringite formation in heat treated mortars and 

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Janssen, D.J. and M.B. Snyder, Resistance of Concrete to Freezing and Thawing. SHRP-C-391, 

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Testing Results, Report FHWA-RD-91-044, FHWA, Nov. 1993. 

Snyder, M.B. and D.J. Janssen, Resistance of Concrete to Freezing and Thawing, SHRP-C-391, 

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oder unbeteiligter dritter?” ZKG International, 51. Jahrgang, Nr. 5, 1998, pp. 280-292 (in 

English and German). 

Vokes, E.A., S.L. Clarke, and D.J. Janssen, “Damping measurements for non-destructive 

evaluation of concrete beams,” Frost Resistance of Concrete, edited by M.J. Setzer and R. 

Auberg, London: E&FN Spon, 1997, pp. 288-297. 

Whiting, D., M. Nagi, P. Okamoto, H. T. Yu, D. Peshkin, K. D. Smith, M. I. Darter, J. Clifton, 

and L. Kaetzel, Optimization of Highway Concrete Technology. SHRP-C-373, Strategic 

Highway Research Program, National Research Council, Washington, DC, 1994. 

41 
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