为避免强度不同对高性能混凝土抗裂性评价结果带来的影响,介绍了高性能混凝土配合比的等强度设计方法. 以掺合料分别为40%粉煤灰、5%硅灰与35%粉煤灰复掺的两组50 MPa配制强度的高性能混凝土为例,进行了配合比的等强度设计,并在此基础上开展了等强度混凝土的抗裂性对比分析. 结果表明:采用胶凝材料影响系数来进行高性能混凝土配合比的等强度设计是可行的;掺5%硅灰的胶凝材料影响系数取值为1. 04是合适的;等强度条件下,不同混凝土的抗裂性存在明显差异,与40%粉煤灰混凝土相比,5%硅灰与35%粉煤灰复掺等强度高性能混凝土的干缩值增大,极限拉伸值降低,开裂敏感性增加.%In order to avoid influence of different concrete strength on crack resistance evaluation, the mixing ratio design of high performance concrete ( HPC) based on equivalent strength was introduced. Two 50MPa HPC examples, single doped by 40% fly ash of, compound doped by 5% silica powder and 35% fly ash, were employed to conduct the mixing ratio design based on equivalent strength and their crack resistances were compared. The results indicated that the design of equivalent strength HPC by using cementing material coefficient is feasible; the cementing material coefficient of 1. 04 for 5% silica powder example is suitable;under equivalent strength condition, the crack resistance of different concretes varied. Compared with the concrete of 40% fly ash single doped, the equivalent strength concrete of 5% silica powder and 35% fly ash compound doped has larger dr-ying shrinkage, lower ultimate tension and higher cracking sensitivity.
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