Exploratory Studies Of Early Strength Development In Portland Cement Pastes And Mortars With List Of References

Author : Harrison Frederick Gonnerman
Publisher :
ISBN 13 :
Total Pages : 64 pages
Book Rating : 4.3/5 (129 download)

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Download or read book Changes in Characteristics of Portland Cement as Exhibited by Laboratory Tests Over the Period 1904 to 1950 written by Harrison Frederick Gonnerman and published by . This book was released on 1952 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes the changes in composition, fineness, and strength-producing characteristics of Type I portland cement as exhibited by laboratory tests over the period 1904 to 1950. The principal changes have been an increase in the average computed C3S content and an increase in fineness, each of which has contributed to higher concrete strengths at all ages up to 10 yr, the latest age of test reported in the paper. Most of these changes occurred during the period 1926 to 1940. Under given conditions of test, current Type I cements attain a strength of 3000 psi in about 4 days and 6000 psi in about 40 days whereas it required about 28 days and 8 years respectively to attain these strengths in comparable concretes made with cements purchased during the period 1916 to 1920. It is particularly noteworthy that, although the changes in composition and fineness have greatly increased the strength at early ages, the gain in strength of moist-cured concrete from 28 days to 10 years has remained approximately the same, about 3000 psi. Included in the paper are data comparing composition, fineness, strength-producing characteristics, volume change, heat of hydration, and sulfate resistance of the five types of portland cement covered by ASTM Specification C 150-49.