NATIONAL BUREAU OF STANDARDS REPORT

5123

QUARTERLY REPORT

ON

EVALUATION OF REFRACTORY QUALITIES OF

CONCRETES FOR JET AIRCRAFT WARM-UP, POWER CHECK,

MAINTENANCE APRONS, AND RUNWAYS

r*" A '3

U-ZziiiS&t

>?, -i?

by

W. L. Pendergast, E. C. Tuma and L. E. Mong

and R. A. Clevenger

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS
U. S. DEPARTMENT OF COMMERCE

Sinclair Weeks, Secretary

NATIONAL BUREAU OF STANDARDS

A. V. Astin, Director

THE NATIONAL BUREAU OF STANDARDS

The scope of activities of the National Bureau of Standards is suggested in the following listing

of the divisions and sections engaged in technical work. In general, each section is engaged in specialized research, development, and engineering in the field indicated by its title. A brief

description of the activities, and of the resultant reports and publications, appears on the inside

of the back cover of this report.

Electricity and Electronics. Resistance and Reactance. Electron Tubes. Electrical Instru- ments. Magnetic Measurements. Process Technology. Engineering Electronics. Electronic

Instrumentation. Electrochemistry.,

Optics and Metrplogy. Photometry and Colorimetry. Optical Instruments. Photographic

Technology. Length. Engineering Metrology.

Heat and Power. Temperature Measurements. Thermodynamics. Cryogenic Physics.

Engines and Lubrication. Engine Fuels.

Atomic and Radiation Physics. Spectroscopy. Radiometry. Mass Spectrometry. Solid

State Physics. Electron Physics. Atomic Physics. Nuclear Physics. Radioactivity. X-rays. Betatron. Nucleonic Instrumentation. Radiological Equipment. AEC Radiation Instruments. Chemistry. Organic Coatings. Surface Chemistry. Organic Chemistry* Analytical Chemistry.

Inorganic Chemistry. Electrodeposition. Gas Chemistry. Physical Chemistry. Thermochemistry. Spectrochemistry. Pure Substances.

Mechanics. Sound. Mechanical Instruments. Fluid Mechanics. Engineering Mechanics.

Mass and Scale. Capacity, Density, and Fluid Meters. Combustion Controls.

Organic and Fibrous Materials. Rubber. Textiles. Paper. Leather. Testing and Specifications. Polymer Structure. Organic Plastics. Dental Research.

Metallurgy. Thermal Metallurgy. Chemical Metallurgy. Mechanical Metallurgy. Corrosion.

Mineral Products. Porcelain and Pottery. Glass. Refractories. Enameled Metals. Concreting Materials. Constitution and Microstructure.

Building Technology. Structural Engineering. Fire Protection. Heating and Air Conditioning. Floor, Roof, and Wall Coverings. Codes and Specifications.

Applied Mathematics. Numerical Analysis. Computation. Statistical Engineering. Mathematical Physics.

Data Processing Systems. Components and Techniques. Digital Circuitry. Digital Systems.

Analogue Systems.

Cryogenic Engineering. Cryogenic Equipment. Cryogenic Processes. Properties of Materials.

Gas Liquefaction.

Radio Propagation Physics. Upper Atmosphere Research. Ionospheric Research. Regular

Propagation Services.

Radio Propagation Engineering. Frequency Utilization Research. Tropospheric Propagation

Research.

Radio Standards. High Frequency Standards. Microwave Standards. • Office of Basic Instrumentation • Office of Weights and Measures
NATIONAL BUREAU OF STANDARDS REPORT

QUARTERLY REPORT

ON

EVALUATION OF REFRACTORY QUALITIES OF

CONCRETES FOR JET AIRCRAFT WARM-UP, POWER CHECK,

MAINTENANCE APRONS, AND RUNWAYS

by

W. L. Pendergast , E. C. Tuitia , L. E. Mong

and R. A. Clevenger

Refractories Section

Mineral Products Division

Sponsored by

Department of the Navy

Bureau of Yards and Docks

Reference: NT4-59/NY 420 008-1

NB3 File No. 9.3/1134-C

NBS PROJECT NBS REPORT

0903-20-4428 J anua ry 2 2, 1957 512 3

Approved

Dr. Samuel Zerfoss

NATIONAL BUREAU OF ST

intended for use within the

to additional evaluation and

listing of this Report, either

the Office of the Director, N: however, by the Government

to reproduce additional copi

Approved for public release by the mai| y published it is subjected

I

on October 9, 2015. prepared if that agency wishes

irogress accounting documents

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS
, . . >
QUARTERLY RfePORT

ON

EVALUATION OF REFRACTORY QUALITIES OF

CONCRETES FOR JET AIRCRAFT WARM-UP, POWER CHECK,

MAINTENANCE APRONS, AND RUNWAYS

i. INTRODUCTION

This phase of the project includes the determination of

the cause or causes of failure that occur in concrete aprons

and runways exposed to jet exhaust gases. A combustion

chamber that delivers hot gases at velocities and temperatures

approximating those of field conditions is being used. The

approach includes instrumentation of the concrete test panels

to determine the heat gradients and stresses set up during

flame impingement at several locations on the test area and

at varying depths below the surface.

2. ACTIVITIES

2.1 Concrete with Diabase Aggregate

As previously reported—^ a concrete was designed with

diabase aggregate. A batch was mixed, specimens were fabricated.

Results of preliminary tests on the diabase aggregate,

the design of the concrete mix using the aggregate, and the

properties of the fresh concrete follow:

n 2 / Coarse— Fine-'

Absorption 0 .

1 .54

Bulk Specific Gravity (SS Dry) 2.96 2 .87

Percent loss in Los Angeles

Abrasion Test - ----- - - 25.9

Ratio of coarse-t o-f ine

aggregate -------- 65 to 35 —^ NBS Report 4869, October 5, 1956.

2 / — The properties of the aggregate were determine on the same

sizings as used in concrete.
' l

-

-

->

i

.
- 2 -

Gradat ion

Coarse

U» S. Standard

Sieve Percent

Fine

U . S . Standard

Sieve Percent

1 22

3/4 30

1/2 18

3/8 15

. 4 15

No 8 16

16 20

30 29

50 25

100 9

Thru 100 1

Properties of Fresh Concrete

Proportions, by weight: Cement ) to coarse and to fine aggregate )

3 / Cement content—

Vinsol resin

Water content : Air content

Slump

Weight of fresh concrete

Water cement ratio

Remarks

3 7.31 sacks/yd of concrete

0.0 17« by weight of cement

3

37~» 7 gals /yd of concrete

2.2% gravimetric method

2.25 inche s 161.44 lbs / ft 3

0.40

Easily placed but harsh

The flexural strength of the concrete after curing for

28 days in fog-room was 845 psi. Heating to 500°C for five

hours (complete immersion) reduced the strength to 305 psi.

Heating to 750°C resulted in a further loss of strength to

100 psi. The cured specimens failed by aggregate fracture

and the heated specimens by bond failure. Two test panels

fabricated from this concrete were subjected to the jet blast.

Both had been cured for 28 days in the fog-room, one had

3 / Designed as a seven-sack mix, calculated to 7.3.
S'

J • . . i . * . . v

V . * I
-3-

been stored at 73°F and 50 percent relative humidity for 28

days; the second had been stored for 49 days at the same

temperature and humidity. This concrete appears to have the

best resistance to the jet blast of any thus far tested.

2.2 Absorption and Evaporation of Water

During Curing and Drying of Concrete

The drying of tile shape specimens, three by three inches,

having different thicknesses, and fabricated with concrete

designed with different aggregates has been continued. These

specimens were vapor proofed on all but one three by three

inch face. The results appear in Table 1.

The results indicate that the dimension of the specimen

is a factor in:

1) The amount of water absorbed during fog-room curing;

2) The amount of water evaporated during storing;

3) The amount of non-e vaporable water in concrete after

storage and drying.

The concrete designed with crushed brick aggregate while

containing less cement than that designed with crushed olivine

aggregate had more combined water after curing and drying.

4 I R. C. Valore found in his work on Cellular Concretes— that

brick dust acts as a pozzolan cement.

The concrete tile fabricated with the crushed building

brick aggregate and those fabricated with the White Marsh

aggregate were stored for nine months after curing. The onehalf inch tiles were the only ones that reached water

4 /

I r, . - *— Cellular Concretes by R. C. Valore, Journal of American

Concrete Institute, May and June 1954.
i

? V yV. S;i

' : ...

. ;

;

<{<' -

j HOC ,V :

' • 7

T o h

i’ ^

' if

'

:< fj> ! . A

t. <5,

*

, > © 1

f

.

i :

3 .'.ri.g. «• •

.

*
4 -
.
-5-

equilibrium undet the conditions of storage l.e. stored at

73°F, 5C percent relative humidity, and vapor proofed on all

but one three-inch face. The one-half inch tile fabricated

with concrete designed using White Marsh aggregate reached

constant weight at seven months storage, the one-half inch

tile fabricated with concrete designed using crushed building

brick reached constant weight at eight months storage. Those

made with concrete using olivine aggregate have not as yet

reached constant weights.

2.3 Humidity in Concrete Specimens

A two-month delay in shipment of the miniature hygrometers,

that are to be used in correlating humidity, at increasing

depths, from the exposed surface, with water loss has deferred

this work.— ^ January 24, is the date now scheduled for

de 1 ivery

2.4 High-Alumina Hydraulic Cement

During the period covered by this report a concrete was

designed with crushed building brick and a high-alumina

hydraulic cement (A1C0A - XCA-25), low in impurities. Specimens

fabricated from a trial batch of this concrete developed

their maximum strength more rapidly than those fabricated

with concrete designed with Portland cement. Specimens

(16 x 4 x 3 inches) fabricated from this concrete developed

a flexural strength of 720 psi during 14 days in the fog-room.

The method was described in detail in NBS Report 4869,

October 5 , 1956
i
- 6 -

Additional specimens after the same curing period were heated

at 500 and 750°C for 5 hours and tested. The flexural

Q strength of those heated at 500 C was 645 ps i and those

heated at 750°C was 585 psi. Concretes designed with Portland,

Portland pozzolan, or Lumnite cement, and tested after such

heat treatments show a loss in flexural strength of from 50

to 60 percent. X*-ray diffraction patterns were made on

o samples of this concrete, after curing, 500 C heat, and

750°C heat. Careful inspection failed to identify any cement

component or a shift in the patterns due to heating. A

study of the effect of heating on neat high-alumina cements

is included in a current project at this Bureau. The data

when available will be included in a future report.

2.5 Pressure Developed in Concrete

During Rapid Rate of Keating

In the study of the pressure developed in concrete, as

the temperature is raised at a rapid rate, a bomb was

constructed. This bomb was equipped with thermocouples

located in different positions in the concrete charge and a

pressure gauge to measure the vapor pressure surrounding the

concrete specimen. The bomb was first checked for performance

using water only and the data from the steam tables was

reproduced. The bomb was then charged with a concrete mix and

cured in the fog-room, and the only water in the system was

that contained in the concrete. During heating at 200 C

per hour the pressures and temperatures in the concrete
.wL />

, 4 c

f F

:i "5

'

• I
-7 ~

charge were recorded. However, the total amount of water

present in the system was so small that the volume of the

colder connecting tubes served as a condenser for the water

vapcr driven from the concrete and only small net pressures

were observed. These net pressures did not develop till the

temperature of the concrete was above 230°C.

Since the pressure gauge must operate at room temperature

it will be necessary to fill the voids of the system with a liquid having a very low vapor pressure for the temperature

of the test. Samples of such liquids have been obtained

including Dow Corning silicone fluid 550, and Esstic Oil 42.

It is noteworthy that only about 23 percent of the water,

originally present, was lost from the concrete in the heat

treatment which included heating to 310°C and cooling to room

temperature in the closed system. Concretes heated in air to

such temperatures loose nearly all of their water.

2.6 Mineralogic Examination of Aggregates

A mineralogic examination was made on aggregates submitted

by NAVCERELABo Six aggregates were examined before and after

four heat shock treatments (1250, 1500, 1800, and 2000°F).

Five sampler representing the predominating material occurring

in San Gabriel gravel and nine samples not marked for an

identification were also examined. ' The results of the

'

I . examination occur in Tables 2, 3, and 4.
JC


TABLE 2. EFFECTS OF THERMAL SHOCK TREATMENT

Aggregate

NBS No. Field Condition before Exposure to Thermal Shock! Thermal Shock

1

Milky quartz, fairly well rounded, trace of muscovite mica and

biotite highly fractured structure,

dense

1250°

3-min.

667-668

Not altered muah , will

hand fracture, will

fracture more readily on outside portion.-

1500°

3^min.

726-727

Open fractures, fractured

readily throughout.!

1800°

3-min.

740-741

O / More open fracture-^

2000°

3-min.

779-780

Same a s 1800° f!

2

Schistose, considerable amount of

micaceous material, high percentage of quartz. Mica, feldspar,

decomposed biotite. Medium dense

fairly friable, badly weathered.!-

661-662

Very little change in structure

722-723

Micaceous material shows

expansion cracking in

weathered specimen,

especially, largo specimen

fractured in various

directions along fresh

surface

752-753

Mica not as fresh appearing as in lower fired

specimens , medium

fracture throughout.

781-732

Badly fractured, quite

friable, alteration of micas.

3

One specimen was a two-feldsrar

biotite granite, quite fresh. One specimen contained mostly quartz

with some feldspar and amphibolo,

garnet also present, rock is

compact and quite fresh.!-'

673-674

Alteration of micas and friability depends on

the extent of weathering

that the specimen undervrent. The more the

weathering th3 more destructive the thermal

exposure

720-721

Micaceous material altered,

expanding especially on

surface , fractured

throughout

744-745

Quite friable ; fractured

throughout, alteration

of micas

787-788 Less micaceous material

than occurred in field

specimens, cruite friable,

failure throujhout .

4

Pegmatite sample shown much

valuation piece to piece.

Principal impurity limonite, iron

stains penetrating the cracks,

recemented quarts grains , occasional manganese staiM,

leached structure, dense.!'

665-666

Fresh fracture on surface

finger breaks readily.

Where iron oxide is isolated iron turning

brownish in color losing

its H2O, highly fractured, new fractures.

No sample

750-751

Same as 1250° F sample

except iron more altered

and more highly fractured.

663-664

Thoroughly fractured

5

Igneous rock, fresh not badly

altered, amphibole gneiss, shows

altering to chlorite, more feldspar than quartz, altered

biotite, enidote.!

669-670

Quite friable, not badly

cracked, some minerals

show alteration on

surface, different samples

show different degrees

of friability.

724-725

Highly fractured, more

friable, alteration of

minerals increasing.

754-755

Increasing in finability

and alteration of

minerals.

783-784

No strength

6

Very dense schist, containing

mica, feldsnar porphyrobla sts, some pebbles are coated with

calcium carbonate. 1

675-676

Schist structure very

notic sable, not much

alteration of minerals.

730-731

Micaceous materials

altering, still only

slight fracture.

742-743

Slight fracture, still

micas oxidizing.

777-776

Highly fractured across feldsrar grain, ground mass and feldspar showing

alteration.

3/

2/

The numbers of the photographs of shock-treated specimens of this aggregate all appeared on this sample.

Inversion temperature cracks.

-9-

TABLE 3

Five samples of the predominating materials that occur

in San Gabriel gravel.

Sample No. 1

Rock, in form of rounded pebbles, containing quarts,

feldspar, biotite, materials quite fresh.

Sample No . 2

Contains a two-feldspar biotite granite and a gneisscid

granite with altered biotite.

Sample No. 3

A two-feldspar red granite (biotite), fairly fresh. A

gray granite (biotite) weathered. A gray granite badly

weathered. A two-feldspar granite (biotite) badly weathered.

Sample highly variable piece by piece.

Sample No* 4

A schistose metamorphic rock, varying considerable in

composition, many of the particles coated with calcium

carbonate

Sample No. 5

A schistose me tamorphi c rock, more uniform than sample

No, 4, and finer grained with darker minerals. Considerable

biotite mica present which has been altered to chlorite in

some specimens.
• >V 1

•

;• v

\ 1 1 ’

; i .

'

.
- 10 -

TABLE 4

The following samples were not marked for our identification. They were, however, examined and may be identified

by the number of the photographs

Picture No. 716-717

Temperature 150C°F/3 min.

A sandstone, high in iron oxide, firm in body, some

fracture s

Picture No. 748-749

Temperature 1800°F/3 min.

Hornblende schist, some fractures recemented with epidote

new fractures* little alteration of minerals, considerable

feldspar, secondary mineral ©pidote, different samples vary

in composition. Smaller samples show greater weathering and

as a result asr@ more friable.

Picture No. 663-664

Temperature 1250°F/3 min.

Feldspar and quartz, not appreciably effected by heat

shock

Picture No. 671-672

Temperature 1250°F/3 min.

Quite similar to materials shown in picture 748-749 but

effected less by lower heat shock.

- 1

-

TABLE 4 (continued)

Picture No. 728-729

Temperature 1500°F/3 min.

A mixture of gneiss and schist, fine of grain, few

fractures, fairly firm.

Picture No. 718-719

Temperature 1500°F/3 min.

Gneiss, thoroughly altered and disintegrated.

Picture No. 746=747

Temperature lS00°F/3 min.

This sample appeared to be similar to sample No. 4 of

the San Gabriel gravel. Minerals altered, especially the

micas, badly weakened.

Picture Ho. 785-786

Temperature 2000°F/3 min.

Appeared to be similar to sample No. 4 San Gabriel gravel,

badly fractured, separated on bedding.

Picture No. 789-790

Temperature 2000°F/3 min.

Schist structure highly fractured, alterations of

micaceous minerals pronounced resembles sample No. 5 of

San Gabriel gravel

- 12 -

No attempt was made to make a detailed petrographic

examination of the materials since it was evident that there

was a wide degree of variability item to item in each sample.

Only the gross effects relating the failure to structure,

mineralogy, and temperature were tabulated. It was noted

that the major failures occurred above 1250°F. The three main

types of failure were: (1) through quartz inversion, especially

when the quartz grains were large; (2) failure through mica

exfoliation, especially pronounced where ih@ mica was in the

advanced weathered condition, and (3) failure through exfoliation of Shistose structure (through expansion and breakdown

of mica, chlorite, quartz, etc) a Though preliminary, one

may point to these three items as quite important to any

aggregate specification for use above 1500°F

3, PLANS FOR NEXT QUARTER

Due to the behavior in our tests of the concrete (Section

2.1) designed with diabase aggregate and its frequency of

occurrence additional tests are planned on concretes using

this aggregate. It is suggested that it be included with

other aggregates now being studied at NACERELAB.

It has been found—' that carbonization occurs during

curing treatment resulting in a greater weight increase for

the smaller specimen. (In proportion to weight-area ratio.)

To determine the extent of this weight increase due to

carbonization (Section 2*2) it is planned to analyze a series

of the concrete specimens for carbon dioxide *

E» T. Carlson and C. M« Hunt, N.B.S* Project 0906-11-0923,

Chemical Properties of Cementing Materials.
" '•

y 1 fft. : 0 " - '
-13-

Further work is planned on the design, fabrication, and

testing of concretes containing A1C0A - XCA-25 cement

(Section 2.4) since this cement is unusual in the concretes

made with it had an exceptionally small percent reduction

in strength resulting in heat treatments.. This type of

cement is now marketed by several manufacturers.

Additional data will be taken to determine the pressures

developed in concrete during heating (Section 2.5).

4. LITERATURE

A review of the following articles was made during the

month

1. La capillarity de s batons manufacturer par L-- Marill

Revue des Materiaux de Construction et de Travaux Public

Edition C, Feburary 1956, No. 485.

Summary

¥

The proper -g ratio is the primary condition necessary

to obtain a low absorption concrete. When the water does

not completely fill the normal voids between the grains of

cement the voids persist after hydration and create a path

for water penetration and at best forming a less dense

concrete

The fineness modulus of the aggregate should be the

one that would develop a compact concrete.

In a very porous concrete the water penetrates thru the

large pores for a distance of several centimeters but can

travel thru large thicknesses by following the small cracks

to the interior of the large pores.
** -

.

... c : ' v v..- : fi

.

t .

. .

1V,,.. ' # 1 ^ (( , ’ s • :•
-14-

A concrete can carry an excess of material that Is similar

in fineness to the cement. However, if a small portion of

this material is of the size of 5 microns, clay or other

materials smaller than 1 micron should not be used. The

addition of clay was not included in this work since its

inclusion is generally known to be harmful.

The cement content is not the predominating factor.

Concretes may be designed that will develop capillaries when

3 the cement content is as low as 160 Kg/m , nevertheless, a low porosity was obtained by going below the 10 percent cement

content using the Joisel method of concrete design.

The method of curing has a marked influence on the

water penetration of concrete. The curing in water has a favorable action in reducing the ares of the capillary network.

The use of an additive to a concrete that already has

good density reduces its porosity.

The use of wax, rubber etc and the techniques of impregnation is another method of obtaining impermeable concrete.

In addition to the interest of building construction

where water tight walls are desirous, the study of the porosity

of concrete can furnish indications as to th® speed of drying

or wetting and consequently the effect on expansion and

contraction observed in construction.

2. Concrete Pavements on the German Autobahnen, F. H.

Jackson and Harold Allen, Journal of the American Concrete

Institute, Vol. 19, Ho, 10, June 1946.
m'ottii L A i-'
- 15 -

This publication is merely an Engineers' report on the

durability of concrete pavements where particular care was

taken in placing and curing concrete. No data is given on

design or mix except accuracy in grading aggregate. Since

this publication is readily available a more detailed summary

is not considered necessary.
; \ ri 6 .v.i

. ;

.

.

-

f

1 '

...

i i
THE NATIONAL BUREAU OF STANDARDS

Functions and Activities

The functions of the National Bureau of Standards are set forth in the Act of Congress, March

3, 1901, as amended by Congress in Public Law 619, 1950. These include the development and

maintenance of the national standards of measurement and the provision of means and methods

for making measurements consistent with these standards; the determination of physical constants and properties of materials; the development of methods and instruments for testing materials,

devices, and structures; advisory services to Government Agencies on scientific and technical

problems; invention and development of devices to serve special needs of the Government; and the

development of standard practices, codes, and specifications. The work includes basic and applied

research, development, engineering, instrumentation, testing, evaluation, calibration services, and

various considtation and information services. A major portion of the Bureau’s work is performed

for other Government Agencies, particularly the Department of Defense and the Atomic Energy

Commission. The scope of activities is suggested by the listing of divisions and sections on the

inside of the front cover.

Reports and Publications

The results of the Bureau’s work take the form of either actual equipment and devices or published papers and reports. Reports are issued to the sponsoring agency of a particular project

or program. Published papers appear either in the Bureau’s own series of publications or in the

journals of professional and scientific societies. The Bureau itself publishes three monthly periodicals, available from the Government Printing Office: The Journal of Research, which presents

complete papers reporting technical investigations; the Technical News Bulletin, which presents

summary and preliminary reports on work in progress; and Basie Radio Propagation Predictions,

which provides data for determining the best frequencies to use for radio communications throughout

the world. There are also five series of nonperiodical publications: The Applied Mathematics

Series, Circulars, Handbooks, Building Materials and Structures Reports, and Miscellaneous

Publications.

Information on the Bureau’s publications can be found in NBS Circular 460, Publications of

the National Bureau of Standards ($1.25) and its Supplement ($0.75), available from the Superintendent of Documents, Government Printing Office, Washington 25, D. C.

Inquiries regarding the Bureau’s reports should be addressed to the Office of Technical Information, National Bureau of Standards, Washington 25, D. C.