Evaluation of strength at early ages of self-compacting concrete with high volume fly ash

Self-compacting concrete (SCC) demands large amount of powder content and fines for its cohesiveness and ability to flow with out bleeding and segregation. In the present investigation, part of this powder is replaced with high volume fly ash based on a rational mix design method developed by the authors. Because of high fly ash content, it is essential to study the development of strength at early ages of curing which may prove to be a significant factor for the removal of formwork. Rate of gain in strength at different periods of curing such as 12 h, 18 h, 1 day, 3 days, 7 days, 21 days and 28 days are studied for various grades of different SCC mixes and suitable relations have been established for the gain in strength at the early ages in comparison to the conventional concrete of same grades. Relations have also been formulated for compressive strength and split tensile strength for different grades of SCC mixes. (C) 2007 Elsevier Ltd. All rights reserved.