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.
| Original language | English |
|---|---|
| Pages (from-to) | 49-54 |
| Number of pages | 6 |
| Journal | ACI Materials Journal |
| Volume | 100 |
| Issue number | 1 |
| State | Published - Jan 2003 |
Keywords
- Curing
- Early ages
- Early strength
- High-strength concrete
- Water-cementitious material ratio