wi nib6'tv

NATIONAL BUREAU OF STANDARDS REPORT

v. Information

Servvc

ire Resear- -

* staBdards

,

. i Uurcau Ok

BAdg. 22S, R^ c

M

20234

Washington,

38^5

EVA

QUARTERLY REPORT

ON

LUATION OP REFRACTORY QUALITIES OF CONCRETES

FOR JET AIRCRAFT WARM-UP, POWER CHECK,

AND MAINTENANCE APRONS

Vj. l. Pendergast, Edward C. Tuma, R. A. Cleverer

<J0>>

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 ih 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. • r

- •---

Electricity. Resistance and Reactance fyleasurements, Electrical Instruments. Magnetic

Measurements. Electrochemistry.. • v v

<

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

Technology. Length. Engineering Metrology.

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

and Lubrication. Engine Fuels. Cryogenic Engineering.

Atomic and Radiation Physics. Spectroscopy. Radiometry. Mass Spectrometry. Solid State Physics. Electron Physics. Atomic Physics. Neutron Measurements. Infrared Spectros- copy. Nuclear Physics. Radioactivity. X-Ray. Betatron. Nucleonic Instrumentation. Radiological Equipment. Atomic Energy Commission Radiation Instruments Branch.

Chemistry. Organic Coatings. Surface Chemistry. Organic Chemistry. Analytical Chemistry.

Inorganic Chemistry. Electrodeposition. Gas Chemistry. Physical Chemistry. Thermochemistry.

Spectrochemistry. Pure Substances. -v; Mechanics. Sound. Mechanical Instruments. Fluid Mechanics. Engineering Mechanics. Mass

and Scale. ^.Capacity, Density, arid Ehrid. Meters. Combustion Control.

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.

Electronics. Engineering Electronics. Electron Tubes. Electronic Computers. Electronic

Instrumentation. Process TechnologyRadio Propagation. Upper Atmosphere Research. Ionospheric Research. Regular Propagation

Services. Frequency Utilization Research. Tropospheric Propagation Research. High Frequency

Standards. Microwave Standards.

©Office of Basic Instrumentation ©Office of Weights and Measures.
NATIONAL BUREAU OF STANDARDS REPORT

NBS PROJECT NBS REPORT

0903-21-1^28 December 31, 1954 3855

QUARTERLY REPORT

ON

EVALUATION OP REFRACTORY QUALITIES OP CONCRETES

POR JET AIRCRAFT WARM-UP, POWER CHECK,

AND MAINTENANCE APRONS

by

W. L. Pendergast, Edward C. Tuma, R. A. Clevenger

Refractories Section

Mineral products Division

Sponsored by

Department of the Navy

Bureau of Yards and Docks

Washington, D. C.

Reference: NT4-59/NY 420 008-1

Project No. 61717

NBS Pile No. 9.3/1134-C

Approved

R. A. Heindl, Chief

Refractories Section

U. $. DEPARTMENT QF COMMERCE

NATIONAL BUREAU OF STANDARDS

The publication, re

unless permission Is

25, D, C. Such per

cal ly prepared If tl

Approved for public release by the

Director of the National Institute ot Standards and Technology (NIST)

on October 9, 2015.

In part, Is prohibited

andards, Washington

port has been spedfiiport for Its own use,

QUARTERLY REPORT

ON

EVALUATION OP REFRACTORY QUALITIES OP CONCRETES

FOR JET AIRCRAFT WARM-UP, POWER CHECK,

AND MAINTENANCE APRONS

TECHNICAL REQUIREMENTS

The technical requirements for the concretes designed

with dense aggregates are the same as those given in NBS

Report 3012, dated December 31 > 1953*

The technical requirement for the concretes designed

with lightweight aggregates are: (1) they must develop a

flexural strength of 650 psi after curing for 28 days in the

fog-room; (2) the maximum cement content shall not exceed

nine sacks per cubic yard.

1. INTRODUCTION

The objective of the investigation is the determination

of the physioal properties of concretes that will evaluate

their suitability for use in jet aircraft warm-up, power

check, and maintenance aprons.

2. MATERIA IS: PREPARATION AND TESTING

2*1 Cements

The thermal length changes from room temperature to

approximately 1200° C were measured on specimens of the three

types of cements. The neat cement specimens for that purpos

were cured for 28 days in the fog-room and oven dried at

105°C for 18 hours before testing.

2

2 0 2 Aggregates

A second shipment, totaling ten tons of sinter-ed slag

was crushed and screened to required sizes.

The following properties of both the sintered slag and

a coated expanded shale, "Rocklite", were determined: (1)

wear in the Los Angeles Abrasion Test; (2) the bulk specific

gravity; (3) the absorption; (4) the unit weight in pounds

per cubic foot.

The thermal length changes, of one of the dense aggregates

namely, crushed building brick, were observed from room

temperature to approximately 1200°C.

2.3 Concretes

During this reporting period 27 one-cubic foot trial

batches of concrete and one 15> cu 0 ft. final batch, were

designed, mixed, specimens fabricated, cured, and tested if

the curing period was completed.

Fifteen of the trial batches were designed with a lightweight aggregate ’’Kenlite” , which is an expanded shale,

crushed. Eleven of these contained the portland cement ns

the bond, two the portland pozzolan, and two the high-alumina

hydraulic cement.

Six trial batches were designed with the second lightweight aggregate, "Rocklite" . Five of these contained the

portland cement, and one the portland pozzolan.
u

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- 3 -

Six trial batches were designed with sintered slag

(second shipment) as the aggregate. Two of each of these

trial batches were designed with port land, portland pozzolan,

and high-alumina hydraulic cements respectively. Using the

information obtained from tests on the trial batches, one

final fifteen cubic feet, batch of concrete was designed

with the high-alumina hydraulic cement as the bond. This

concrete has been mixed and test specimens fabricated. One

set of specimens is being cured in fog-room for 28 days.

Pour sets ha\e completed the seven-day fog-room curing and

are stored in the laboratory at ordinary temperatures and

humidity. These specimens will be tested after two different

curing periods and three heat exposures.

3. RESULTS AND DISCUSSION

3.1 Cements

Preliminary observations of the thermal length changes

of the thi'ee neat cements were made up to that temperature

at which either softening or rapid shrinkage occurred.

When all tests are completed curves showing the length changes

The results of the tests of trial batches of concretes

using sintered slag and given in NBS Report 3705* Table 3 » indicated that a concrete could be designed that would meet

the specified technical requirements. However, because the

properties of the second shipment of slag differed

considerably from the first; additional trial batches of

concretes were prepared and tested.

- k -

during actual heating will be given in a future report and

discussed in detail. For the present it can be pointed out

that the portland cement had a total shrinkage of 7 . 66% up

to 1180°C, itfhich was more than double chat of either the

Portland pozzolan or the high alumina cements.

3.2 Aggregates

Some properties of two of the aggregates are given in

Table 1.

Table 1. Properti es of Lightweight Aggregates

Aggregate Size

Bulk

Specific, . Gravity—- —

S“SD

Water

Absorption

in percent,

by Weight—''

Wear in

Los Angeles

Abrasion Test

percent

Rocklite Coarse

Fine

1.21)

1

c'° 6 .1)5

1145

25.1

Sintered

Slag—'

Coarse 1 0 83 9.20 67.5

Fine 2.72 0.80

Sint ere/3

Slag^/

Coarse 2.16 3.86 1)5.3

Fine 2.1)9 3.18

£./ Saturated surface-dry basis.

b/ The gradation of the aggregate was the same as that used

in designing the concretes.

SJ First shipment of slag sintered at Armour Institute

Laboratories

j / ~ Second shipment of slag sintered on contract by Armour

Institute
. .. 7 i ' ! t
While the bulk specific gravity of the coarse aggregate

of Rocklite, (-1 l/2 n to *4) was 1*24, some of the larger

size particles are lighter than water. In mixing c^mcr-e-te

designed with this aggregate the slump must be kept between

two and three inches to prevent the segregation of the

larger particles. The 25 percent wear loss in the abrasion

test is not a true measure of the strength of this aggregate.

The volume of the charge due to ins lightweight reduces

the impact during the testing and very few of the pieces

actually fractured. The indicated loss was a result of

wear on the coating.

A comparison of the results of tests of the slags

received in the first and second shipments indicates that

if the slag was from the same source the method and/or

temperature of sintering must have differed.

The thermal length changes for specimens cut from

building brick, were characterized by a rapid expansion

approximating 5*0 percent caused by bloating, within the

range from 1000'°C to 1175°C. The total amount of expansion

from 25° to 1000 c c was 0„72 percent. Graphs showing in

detail the length changes are being prepared and will

appear in the next report*
2.0

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- 6 -

3.3 Conc retes

Table 2 gives the composition, some properties of the

fresh concretes, together with the flexural strengths, of

trial batches of mixes designed with the lightweight

aggregate ”Rocklite ,f . The few mixes designed and tested

have not developed the required flexural strength of 650 psi

even with a cement content of slightly more than the maximum

of nine sacks per cubic yard. This aggregate, when used

in concrete, fractures exposing numerous and sizeable air

voids. It is, however, probable that a systematic increase

in the ratio of coarse -to -fine aggregate may result in a concrete with the required strength. An examination of the

fractured beams fabricated from these concretes shows a

deficiency in the intermediate sizes of the coarse ("3/4 +3/8)

This deficiency may be overcome by the increase in the ratio

of coarse-to-f ine aggregate, otherwise a change in the

fineness modulus of the coarse aggregate will be necessary.

The spherical shape of the aggregate will permit the

increase in coarse fractions without materially effecting

the workability of the concrete.

Table 3 gives information similar to that given in

Table 2, but governs mixes designed with the lightweight

aggregate, !f Kenlite t!

. Of the 14 concretes tested only two,

namely, Z-K-C^ and P-K-S^ developed the required 6^0 psi.

In both of these the cement content, as calculated, was

over the nine-sack maximum permitted.

Remarks

Cured

Concrete

few

pull-outs

;

mostly

fractured

aggregate

few

pull-outs;

mostly

fractured

aggregate

few

pull

-out

8;

large

aggregate

fractures

few

pull-outs;

large

aggregate

fractures

Flexural Strength

•H u\ ua O

0

D, vOh rXTN <r\ UA

O'UA 11

Remarks

Fresh

Concrete

easily

placed

placed

well;

sticky

easily

placed

easily

placed

harsh

but

placeable

sticky

but

placeable

&1.9

-p a +> 0.38 0.37 0.37 0.35 0.34 0.40

3 0 £ § 3: Gh OO

g R 3 8 R 3

CD 'O OJ O' 1—1 O' O'

XI O O O' Q O' O'

rH i-H H

Slump inches 6.00 3.00 6.00 2.50 1.75 2.25

Air

Content

Gravimetric

percent 6.78 2.25 4.25 3.19 2.82 2.46

100

u

+>£

5

£S

OO H <*A CV CA <*A ° O' Q CO nO O'

C*A C»A -3- OA OA C<A OA £

a

to

1 1

Vinsol 1

Resin

by

Weight

of

Cement

percent 0.005 0.005 0.005 0.005 0.005

none

•p1

s0

1

§0 sacks/yd^

of

concrete

9.15 9.75 9.16 9.38 8.97 8.68

Pi0

port

ions

by

Weight:

Cement

to

Coarse

and

to

Fine

Aggregate

1

:

0.84

:

0.69

1

:

0.84

:

0.69

1

:

0.88

:

0.72

1

:

0.89

:

0.73

1

:

1.03

:

0.68

1

:

1.04

:

0.70

.9-p

a

p

s

•dM

H CM H CV H 0*J f f <P <P V V

« Cf « « v

<¥

CX. O- P-. (X cx. tsi

£i•H

tu

TABLE

3.

PROPERTIES

OF

FRESH

CONCRE'

Remarks

Cured

Concrete

all

large

aggregate

fractured;

air

voids

90%

fracture;

air

voids

practically

all

large

aggregate

fractured

practically

all

large

aggregate

fractured

few

large

air

voids;

all

large

aggregate

fractured

few

large

air

voids;

all

large

aggregate

fractured

all

large

aggregate

fractured;

few

large

air

voids

all

large

aggregate

fractured;

few

air

voids

2

or 3

pull-outs;

all

other

fractures

few

pull

-out 8

very

few

pull-outs

mostly

aggregate

fracture

few

pull-outs

numerous

air

voids

few

pull-outs

numerous

air

voids

mostly

aggregate

fracture

Flexural Strength pai 520 550 620 620 655 545 605 585 615 575 625 585 620 690

1

1k

Fresh

Concrete

bleeds;

aggregate

segregation

very

good;

slightly

plastic

slightly

harsh

good

slightly

harsh

and

dry

slightly

harsh

slightly

harsh;

bleeds

some

very

good

slightly

harsh

easily

placed

too

wet

very

good

placed

well

very

harsh

harsh

but

placeable

very

good

si-3

+» i -p £<3 5 -4-0 0 o Q -4 CO rH -4 O' C*- CM O' 0 O' UNoooC'N (T\ UN -3- -4 (A -4 ONCNCN PN CH C'N o o o o o odd dodo

Weight

Fresh

Concrete lWft 3

95.00 97.50

101.00 101.60 104.80 99.70 98.80100.60 100.30 98.40102.80 100.30 98.70

103.10 100.00

$

inches

too

thin

2.50 1.25 3.50 1.50 2.00 7.50 4.00 1.00 6.00 1.50 2.00 0.50 1.00 2.25

Air

Content

Gravimetric *OOOC- © Q UN CM Q COUN UNH

(V

C'N NO<55 S-O't-O S- CV UN-4QO O H -4 un g^C-C--4 iH O ON UN CM C'N -4 -4 tO O' C'N UN

Water

Contents |

C8

un no o O' to -4 cv r- o o r- O' o O' to 0-4-40 C- tv ON to CN UN O' O' ON Q tQ C'- -4 C'N C*\ -4 -4 -4 ON -4 ON ON ON ON cA ON ON

ON£

i

Vinsol

Resin

by

Weight

of

Cement

percent 0.010 0.010 0.005 0.005

none none 0.005

none 0.005 0.005 0.005 0.005 0.005 0.005 0.005

Cement

Content

©1

a

ooH R Sj 8 8 5 3 8 jf ass 3 8 3 3

ON C*- O' to O' to to O' O' to O' O' O' O' to I.o

3

-p1 3 1

•S'? tl

£ to

Coarse

and

to

Fine

Aggregate

1

!

0.88

:

l.K)

1

:

0.88

:

1.10

1

:

0.95

:

0.78

1

:

0.95

:

0.78

1

:

0.74

:

0.88

1

:

0.94

:

0.71

1

!

0.89

:

0.74

1

:

0.91

:

0.69

1

:

0.98

:

0.65

1

:

0.99

:

0.66

1

:

0.99

:

0.66

1

:

0.92

:

0.69

1

:

0.99

:

0.66

1

!

0.99

:

0.66

1

:

1.06

:

0.70

-P3

•HS

1a

H CM H tv H CV rH tv H tv Cvl CV H rH rH 7 7 7 7 7 7 7 7 777 7 7 7 7 Til & id bd bd bd M bd bd bd bd bd bd bd bd UJ

i L Li oucucu a. m si a, siL a«iTia. a. .hill* ih p*

-S £

O oj © -P C -3 $ S) 3 1} S

2

- 7 -

An increase in cement content , systematic changes in

the ratio of coerse-to-f me aggregate, and a reduction in

air and water content have failed to yield a concrete of

satisfactory strength. This aggregate is marketed in a top

size of +l/2 inch. The ratio of coarse-to-f ine aggregate

has been increased until the concrete is difficult to place

(too harsh). The manufacturer has been contacted for the

purpose of obtaining a larger top size aggregate. The

introduction of a larger size, but in the same amount, may

yield a concrete with good placeabllity and sufficient

flexural strength.

Table 4 gives information similar to that in Tables 2

and 3 but covering trial batches of mixes designed with

sintered slag from the second shipment. The results of

tests of these trial batches indicate that sufficient

strength will develop in concretes with a much lower cement

content than first indicated when the slag originally

furnished was used. Table 4 also gives the composition

and the properties of the fresh concrete of a final, 15 cubic

foot batch, of concrete designed with the high-alumina

hydraulic cement and using sintered slag from the second

shipment as the aggregate. Due to the limited capacity of

our mixer, namely five cubic foot, it was necessary to make

three separate batches (L-SS-1,2,3) identical in composition.
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TABLE

U.

PROPERTIES

OF

FRESH

CONC

- 8 -

amount of water added, method of charging mixer, and time

of mixing* The results indicate the variation that may

be expected in handling this type of concrete*

Table 5 gives the flexural strengths of seven concretes

after different curing periods. The results were obtained

on prisms 3 x l\ x 16 inches therefore cannot be compared

with the results for 6 x 6 x 20-inch beams fabricated

from the same concretes. All concretes were designed

with the lightweight aggregate ”Kenlite u but with varying

ratios of cement to eoarse-to-fine aggregate. Sane

producers of lightweight aggregate recommend ZS days

fog-room curing, others \\2 days and some recommend

additional curing or air drying. It is evident from these

results that the curing, and curing and drying periods,

s v r engt h drasticallyaffect the ultimate

Table 5» The Flexural Strength of Concretes, Containing a Lightweight Aggregate , as Related ~to Method of Curing*

Identification^/

Curing Period—''

c/ Flexural Strength—' Fog-room Dried at laboratory

Temperature

"l days days psi

P-K-Aj-1 7 76 wo

P-K-A -2 83 655

P-K-A?-l 7 77 265

P-K-A -2 84 795

P-K-B^-l 7 69 270

P-K-B-2 76 730

P-E-Bp-1 7 69 245

P-K-B-2 76 695

s-k-c3--i 7 53 215

Z-K-C-2 60 725

2-E-Cp-l 7 53 395

Z-K-C-2 60 655

P-K-C^-l 7 53 225

P-K-C-2 60 695

a/The first letters: p = Portland cement! Z * Portland pczzolan cement.

The second letter: K = Kenlite, the lightweight aggregate.

The third letter identifies the composition of the mix and the

superscript denotes the gradation of the aggregate.

The numeral identifies the specimen. Specimens 1 and 2 were fabricated from same batch. Comparison of" strength is intended betwee

specimens land 2 of a pair and not between pairs fabricated from

different concretes.

h/The length of the curing period is given as a matter of informatio

since it indicates the effect of extending the curing and drying

on the flexural strength of concrete specimens. It is not neces

sarily recommended as "a suggested curing period or method. Base

on the values of Young’s modulus of elasticity, determined

periodically by the dynamic method, the indication was that the

strength became reasonably constant preceding the final seven

days of curing and drying.

c/a 11 specimens had seven days fog-room curing. One set identified

by the numeral (1) was removed from fog-room after seven days

and stored in laboratory at prevailing temperatures and

humidities. The second set Identified by the numeral (2) was

stored in fog-room until tested. The average flexural strength

of the specimen of the seven concretes that were cured for

seven days in fog-room and dried In laboratory was 295 psi. The

average for those tested out of fog-room was ?05 psi.
rv>
C ONZERENCE

A conference was held at the Bureau of Yards and Docks,

December 1, 1954* The names of those attending follow:

Commander Stanley Rockefeller, Bureau of Yards and Docks

Mo P. Harrington, Bureau of Yards and Docks

P. Knoop, Bureau of Yards and Docks

L« A. palmer. Bureau of Yards and Docks

P. P. Brown, Bureau of Yards and Docks

S. E. Matullo, Bureau of Yards and Docks

J. A. Bishop, NAVCEREXAB

R. Ao Heindl, National Bureau of Standards

W. L° Pender gas t, National Bureau of Standards

As a result of the investigative work thus far

completed at the National Bureau of Standards the Department

of the Navy, Bureau of Yards and Docks, instructed their

laboratories at Port Hueneme , California, to place concrete

aprons for field tests. The nine concretes selected and

recommended for use in these field tests were those

containing refractory aggregates. The recommendation

was based on the evaluation of suitability tests of the

18 concretes investigated. The final nine concretes were

further classified with respect to occurrence and access!-'

bility of the aggregates and the cost of the cement.

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 consultation 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 Basic 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. Inquiries regarding the Bureau’s reports and

publications should be addressed to the Office of Scientific Publications, National Bureau of

Standards, Washington 25, D. C.
!!I