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Approved for public release by the

Director of the National Institute of

Standards and Technology (NIST) on October 9, 2015.

NATIONAL BUREAU OF STANDARDS REPORT

7578

QUARTERLY REPORT

ON

EVALUATION OF REFRACTORY QUALITIES OF

CONCRETES FOR JET AIRCRAFT WARM-UP, POWER CHECK,

MAINTENANCE APRONS, AND RUNWAYS

by

James V. Ryan, E. C. Tuma, D. K. Ward

<QJBS>

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS
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. Research projects are also performed for other government

agencies when the work relates to and supplements the basic program of the Bureau or when the Bureau's

unique competence is required. The scope of activities is suggested by the listing of divisions and sections on the inside of the back cover.

Publications

The results of the Bureau's research are published either in the Bureau’s own series of publications or

in the journals of professional and scientific societies. The Bureau itself publishes three periodicals avail- able from the Government Printing Office: The Journal of Research, published in four separate sections,

presents complete scientific and technical papers; the Technical News Bulletin presents summary and pre- liminary reports on work in progress; and Basic Radio Propagation Predictions provides data for determining

the best frequencies to use for radio communications throughout the world. There are also five series of nonperiodical publications: Monographs, Applied Mathematics Series, Handbooks, Miscellaneous Publications,

and Technical Notes. A complete listing of the Bureau's publications can be found in National Bureau of Standards Circular

460, Publications of the National Bureau of Standards, 1901 to June 1947 ($1.25), and the Supplement to National Bureau of Standards Circular 460, July 1947 to June 1957 ($1.50), and Miscellaneous Publication 240,

July 1957 to June 1960 (Includes Titles of Papers Published in Outside Journals 1950 to 1959) ($2.25); avail- able from the Superintendent of Documents,’ Government Printing Office, Washington 25, D. C.
NATIONAL BUfiEAlJ OF STANDARDS REPORT

ms pmmcr ms HEPORT

1002-12-10472 August 2, 1962 7578

QUARTERLY REPORT

ON

EVALUATION OF REFRACTORY QUALITIES OF

CONCRETES FOR JET AIRCRAFT WARM-UP , POWER CHECK,

MAINTENANCE APRONS, AND RUNWAYS

by

James V. Ryan, E. C. Tuma, D. K. Ward

Fire Research Section

Building Research Division

Sponsored by:

Department of the Navy

Bureau of Yards and Docks

Reference: Task Y-F015-15-102

NBS File No. 10.02/10472

IMPORTANT NOTICE

NATIONAL BUREAU OF STANDARDS REPORTS are usually preliminary or progress accounting documents

intended for use within the Government. Before material in the reports is formally published it is subjected

to additional evaluation and review. For this reason, the publication, reprinting, reproduction, or open-literature

listing of this Report, either in whole or in part, is not authorised unless permission is obtained in writing from

the Office of the Director, National Bureau of Standards, Washington 25, D. C. Such permission is not needed,

however, by the Government agency for which the Report has been specifically prepared if that agency wishes

to reproduce additional copies for its own use. <NBS>

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

QUARTERLY REPORT

ON

EVALUATION OF REFRACTORY QUALITIES OF

CONCRETES FOR JET AIRCRAFT WARM-UP, POWER CHECK,

MAINTENANCE APRONS, AND RUNWAYS

1. INTRODUCTION

The purpose of this project is the development of criteria

for the fabrication of jet exhaust resistant concre-tes. Concretes under development are evaluated by exposure to hot gases

from a combustion chamber. The combustion chamber delivers

these gases at velocities and temperatures approaching field

conditions

.

2. ACTIVITIES

Measurements and tests were made with ten concrete specimens during the quarter. Five were made with blast-furnace

slag concrete (P-BF-10) ; the other five were made with diabase

concrete (P-Di-18) . The concretes are described below.

Cement content, sacks/yd^

P-BF-10 P-Di-l8

7.6 10

Vinsol resin, % by wt of cement .01 .01

Water content, gal/yd^ of concrete 38.2 54.3

Air content, %, gravimetric 7.7 None

Slump, in. 3 4 1/2

Water/cement ratio by weight .45 .48

Each set of five specimens included two 6 in. high truncated

cones, as illustrated In NBS Report 7486 and three 2 1/2 by

4 1/2 by 9 in. bricks cast and vibrated in steel molds. One

of the latter had thermocouples at the top surface and at 1/8,

1/4, 3/8, and 1/2 in. therefrom.
- 2 -

2.1 Steam Pressure Applied to Concrete

The truncated cone specimens were subjected to s-team at

300 psi applied over the base. The pressure forced the specimens upward against a restrained rubber sleeve, thereby improving the seal and preventing leakage between the concrete

and the sleeve. The temperature distributions were essentially

the same in all four specimens but measurable internal / pressures

were observed in only one of each aggregate. Pressures as high

as 225 psi were observed. No moisture came through the concrete

of any specimen.

The fact that pressures were not observed during two of

the tests was believed due to pinching of the pressure probe

tubes as the conical specimens moved under the influence of the

applied steam pressure.

2.2 Air Permeabilities

Measurements of air permeability of each* of four brickshaped specimens were made before and after being subjected to

pressure differentials in the range 100, to 300 psi. The results indicate that the permeabilities of the particular diabase

and blast furnace slag aggregate concrete cast specimens were

appreciably lower after exposure to high pressures than before.

This is contradictory to the results obtained with sawed specimens. The measurements were made a few hours after the high

pressures were released. No attempt has been made to determine

if the reduced permeability effect is permanent or temporary.

The results also indicate that the permeability apparently

changes as the air flow at low pressure differential is continued for several hours. Although an ultimate steady-state

permeability may be reached, it is doubtful that it is directly

applicable to the short times and rapid changes associated with

jet-blast exposure.
-3-

2.3 Temperature Gradients

Two brick shaped specimens, one of diabase aggregate

and one of slag aggregate concrete, were subjected to jet

blast test. The temperature gradients were observed by

thermocouples at 1/8 in. depth increments over the first 1/2 in.

Following the jet-blast test and cooling, the blast furnace specimen was immersed in water for a period of 2 to 3 hays, the surfaces wiped to remove excess water, and resubjected to jet blast

test. The time-temperature curves (see fig. 1) from the test and

retest did not show the characteristic flattening near 100°C due

to changing of water to steam. This flattening had been observed

in jet blast tests of 6 by 18 by 18 in. specimens soaked and retested. The diabase aggregate brick spalled in the initial exposure and was not retested. Figure 2 shows the temperatures versus depth at 15 second intervals until after the time at which the

diabase specimen spalled.

2.4 Specimen Preparation

In view of the probability that movement and sealing of the

truncated cone specimens lead to pinching of the pressure probe

tubes, it was decided to modify the specimen design and the test

method. Specimens were 6 in. thick by 13 1/2 in. diameter. Instrumentation consisted of probe tubes and thermocouples similar

to those in the truncated cone specimens plus thermocouples at

1/8 -in. depth increments for gradient measurements in the first

1/2 in. The specimens will be exposed to hot gases, at temperatures equal to the jet blast but not moving at high velocities,

over the central 6 in. diameter area of one face. The greater

diameter of the specimen was chosen to eliminate the need for

sealing the periphery. The choice of hot gases rather than steam

permits closer approximation to the jet blast test and precludes

the introduction of extra moisture into the specimen.

It was believed that the surfaces of the permeability specimens, resulting from the use of steel molds, and the separation,

resulting from vibration, may have affected the results obtained.

Therefore, new specimens were prepared by casting oversize slabs

from which 9 by 4 1/2 by 2 1/2 in. specimens were sawed.

Specimens were also prepared for drying shrinkage, thermal

expansion, and shear strength tests. Specimens were prepared

with diabase aggregate concrete and with blast furnace slag aggregate concrete. All specimens of a given concrete were cast at

the same time from a single batch. Both slump (mix water) and

vibration were held to minimum values.
AThe concretes are described below.

Cement content, sacks/yd^

Vinsol resin, % by Wt of cement

Water content, gal/yd^ of concrete

Air content, %, gravimetric

Slump, in.

Water/cement ratio, by wt.

BF-1 Di-1

6.9 6.8

.01 .01

36.7 33.7

2.8 2.8

2 lA

.47 A5

2 o 5 Personnel

Mr. Wm. Pendergast, long time project leader retired

as of the end of the quarter and was succeeded by Mr. J.V. Ryan.

USCOMM-NBS-DC
TEMPERATURE

RISE,

1200 —P-BFiO

— — P-BF-IO, RETEST —- P-Di-18

TIME, MIN.

FIG TEMPERATURE- TIME DATA
DEPTH,

IN.

FIG

2.

TEMPERATURE

VERSUS

DEPTH

DURING

FIRST

MINUTE

OF

JET

BLAST.
U. S. DEPARTMENT OF COMMERCE

Luther H. Hodges, Secretary

NATIONAL BUREAU OF STANDARDS

A. V. Astin, Director THE NATIONAL BUREAU OF STANDARDS

The scope of activities of the National Bureau of Standards at its major laboratories in Washington, D.C., and

Boulder, Colorado, is suggested in the following listing of the divisions and sections engaged in technical work.

In general, each section carries out specialized research, development, and engineering in the field indicated by

its title. A brief description of the activities, and of the resultant publications, appears on the inside of the

front cover. WASHINGTON, D. C.

Electricity. Resistance and Reactance. Electrochemistry. Electrical Instruments. Magnetic Measurements,

Dielectrics. High Voltage.

Metrology. Photometry and Colorimetry. Refractometry. Photographic Research. Length. Engineering Metrology.

Mass and Scale. Volumetry and Densimetry.

Heat. Temperature Physics. Heat Measurements. Cryogenic Physics. Equation of State. Statistical Physics.

Radiation Physics. X-ray. Radioactivity. Radiation Theory. High Energy Radiation. Radiological Equipment.

Nucleonic Instrumentation. Neutron Physics.

Analytical and Inorganic Chemistry. Pure Substances. Spectrochemistry. Solution Chemistry. Standard Refer- ence Materials. Applied Analytical Research. Crystal Chemistry.

Mechanics. Sound. Pressure and Vacuum. Fluid Mechanics. Engineering Mechanics. Rheology. Combustion

Controls. Polymers. Macromolecules: Synthesis and Structure. Polymer Chemistry. Polymer Physics. Polymer Characterization. Polymer Evaluation and Testing. Applied Polymer Standards and Research; Dental Research.

Metallurgy. Engineering Metallurgy. Microscopy and Diffraction. Metal Reactions. Metal Physics. Electrolysis

and Metal Deposition.

Inorganic Solids. Engineering Ceramics. Glass. Solid State Chemistry. Crystal Growth. Physical Properties.

Crystallography.

Building Research. Structural Engineering. Fire Research. Mechanical Systems. Organic Building Materials. Codes and Safety Standards. Heat Transfer. Inorganic Building Materials. Metallic Building Materials. Applied Mathematics. Numerical Analysis, Computation. Statistical Engineering. Mathematical Physics. Operations Research. Data Processing Systems. Components and Techniques. Computer Technology. Measurements Automation.

Engineering Applications. Systems Analysis.

Atomic Physics. Spectroscopy. Infrared Spectroscopy. Solid State Physics. Electron Physics. Atomic Physics.

Instrumentation. Engineering Electronics. Electron Devices. Electronic Instrumentation. Mechanical Instru- ments. Basic Instrumentation. Physical Chemistry. Thermochemistry. Surface Chemistry. Organic Chemistry. Molecular Spectroscopy. Molecular Kinetics. Mass Spectrometry,

Office of Weights and Measures. BOULDER, COLO.

Cryogenic Engineering Laboratory. Cryogenic Equipment. Cryogenic Processes. Properties of Materials. Cryogenic Technical Services. CENTRAL RADIO PROPAGATION LABORATORY

Ionosphere Research and Propagation. Low Frequency and Very Low Frequency Research. Ionosphere Research. Prediction Services. Sun-Earth Relationships. Field Engineering. Radio Warning Services. Vertical Soundings Research.

Radio Propagation Engineering. Data Reduction Instrumentation. Radio Noise. Tropospheric Measurements.

Tropospheric Analysis. Propagation-Terrain Effects. Radio-Meteorology. Lower Atmosphere Physics.

Radio Systems. Applied Electromagnetic Theory. High Frequency and Very High Frequency Research. Modulalation Research. Antenna Research. Navigation Systems.

Upper Atmosphere and Space Physics. Upper Atmosphere and Plasma Physics. Ionosphere and Exosphere Scatter, Airglow and Aurora. Ionospheric Radio Astronomy.

RADIO STANDARDS LABORATORY

Radio Physics. Radio Broadcast Service. Radio and Microwave Materials. Atomic Frequency and Time-Interval

Standards. Millimeter-Wave Research.

Circuit Standards. High Frequency Electrical Standards. Microwave Circuit Standards. Electronic Calibration

Center.