大掺量粉煤灰制备水下不分散混凝土及性能研究

Preparation and performance of underwater non-dispersible concrete with large amount of fly ash

因为特殊的施工环境,需要动态平衡水下不分散混凝土的新拌流动性能和抗分散性能。研究了大掺量粉煤灰对混凝土工作性能、抗分散性和力学性能的影响。结果表明,粉煤灰掺量不大于50%时,可以实现大掺量粉煤灰水下不分散混凝土的制备。综合考虑材料性能和经济性能,粉煤灰掺量为50%时水下不分散混凝土性能较优,此时新拌混凝土坍落度、扩展度分别为250、545 mm;屈服应力、塑性黏度分别为47.4 Pa、4.4402 Pa·s;抗分散性能良好;7、28 d抗压强度及水陆强度均达到一等品要求。

Because of the special construction environment,there is a need to dynamically balance the fresh flow properties and anti-dispersion properties of underwater non-dispersible concrete.This paper studies the influence of large amount of fly ash on the working performance,dispersion resistance and mechanical properties of concrete.The results show that the preparation of underwater non-dispersible concrete with large amount of fly ash can be realized by adding less than 50%fly ash to concrete.In particular,with 50%fly ash admixture,the slump and extension of fresh concrete were 250 mm and 545 mm,respectively;the yield stress and plastic viscosity were 47.4 Pa and 4.4402 Pa·s,respectively;the anti-dispersion performance was good,and the 7 d and 28 d compressive strengths and surface strengths reached the standard of first-class products.