Title:
Velocity-Strength Relationship of Concrete by
Impact-Echo Method
Author(s):
Hoi-Keun Lee, Hyunjune Yim, and Kwang-Myong Lee
Publication:
Materials Journal
Volume:
100
Issue:
1
Appears on pages(s):
49-54
Keywords:
curing; early ages; early strength; high-strength concrete; water-cementitious material ratio.
DOI:
10.14359/12462
Date:
1/1/2003
Abstract:
This paper describes using the impact-echo method to evaluate the early-age strength of normal- and high-strength concrete. Impact-echo and compression tests were carried out between 12 h and 28 days to measure the rod-wave velocity and compressive strength, respectively, of concrete specimens with various water-cementitious material ratios (w/ cms) between 0.58 and 0.27. Test results demonstrate that the velocity-strength relationship of normal-strength concrete with w/ cms ranging from 0.58 to 0.35 is noticeably different from that of high-strength concrete with w/ cms below 0.35. Also noted in this study is that the velocity-strength relationship of normal-strength concrete was influenced by the curing age of the specimen. The addition of fly ash (FA) had little influence on the velocity-strength relationship of either normal- or high-strength concrete specimens. Based on these observations, formulae to determine the relationship between the strength and wave velocity of concrete were proposed that incorporate the effects of the w/ cm and the curing age of the specimen.