Page images
PDF
EPUB
[blocks in formation]

Interrelations Between Cement and
Concrete Properties, Part 3

Compressive Strengths of Portland Cement
Test Mortars and Steam-Cured Mortars

Architecture

Library

TH

[merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small]

RELATED PUBLICATIONS

NBS Monograph 28-Causes of Variation in Chemical Analyses and Physical Tests of Portland Cement-25 cents*

NBS Monograph 43-Chemistry of Cement Proceedings of the Fourth International Symposium-Washington 1960. Presented in two volumes. Volume I-$6.50. Volume II-$6.25. The two volumes at $12.75 a set. (Originally issued September 1962, and reprinted February 1964.)

NBS Building Science Series 2 and 5-Interrelations between Cement and Concrete Properties. Part 1-35 cents. Section 1, Materials and Techniques. Section 2, Water Requirements of Portland Cement. Section 3, Occurrence of Minor and Trace Elements in Portland Cement. Part 2-35 cents. Section 4, Variables associated with expansion in the potential sulfate expansion test. Section 5, Heat of hydration of portland cement. Section 6, Variables associated with small autoclave expansion values of portland cements.

*Order publications from Superintendent of Documents, Government Printing Office, Washington, D.C. 20402. (For foreign mailing, add one-fourth of the price of the publication.)

Library of Congress Catalog Card Number: 64-60095

II

Section 7. Compressive Strength of Test Mortars

R. L. Blaine, H. T. Arni, and M. R. De Fore

The relationships between cement characteristics and compressive strength of 1:2.75
(cement to graded Ottawa sand) mortars of standard consistency at ages of 24 hours to 10
years, and made with 199 cements of different types, were studied by fitting multivariable
regression equations with the aid of a digital computer. The dominant variables associated
with the differences of compressive strength, strength gain, and strength ratios were different
at the various test ages, and after different curing conditions. The additional use of certain
trace elements with commonly determined independent variables resulted in a significantly
better fit between the equations and the observed data. Interactions between the fineness
values and other independent variables were noted. Certain parallelisms and differences
were noted with respect to variables associated with compressive strength differences at
various ages and the heat of hydration of the cements at these ages.

Key Words: Chemical composition, fineness, heat of hydration, strength gain of
portland cements, trace elements.

[blocks in formation]
[blocks in formation]
[blocks in formation]

These specification tests are usually made

early ages, for example, 1 and 3 days, 3 and 7da
or occasionally at 7 and 28 days. The val
obtained, together with knowledge of the chemi
composition of the cements, are used, to so
extent, to predict the potential strength, or
strength at later ages of mortars or concretes m
from these cements. Lack of complete informat
on the variables associated with gain in co

« PreviousContinue »