不同粒径石英粉对活性粉末混凝土强度影响及微观结构分析

Effect of Quartz Powder with Different Particle Size on the Strength and Microstructure of Reactive Powder Concrete

试验分析了不同养护条件下掺加不同目数石英粉对活性粉末混凝土(RPC)抗压、抗折强度影响,分析并计算不同目数石英粉对RPC强度贡献率;利用SEM、XRD分析不同目数石英粉经历热养后RPC微观结构变化和物项组成.结果表明:与未掺石英粉相比,掺入石英粉对RPC抗压、抗折强度均有提升,其抗压/抗折强度最高可提升18.9%/14.1%;不同养护条件下石英粉对于RPC强度贡献率均大于0,且对抗压强度贡献率更为显著.微观分析表明,石英粉作为一种惰性材料,虽在一定养护条件下无法通过发挥化学活性效应提升基体强度,但可间接影响其他掺合料的化学活性效应对基体强度产生影响.

The influence of quartz powder size on compressive strength and flexural strength of reactive powder concrete(RPC)under different curing conditions was analyzed through an experimental study.The microstructure change and material composition of RPC after heat curing of different mesh quartz powder were analyzed by SEM and XRD.The results show that:compared with no quartz powder,the compressive strength and flexural strength of RPC are improved by adding quartz powder,and the highest compressive/flexural strength can be increased by 18.9%/14.1%;under different curing conditions,the contribution rate of quartz powder to RPC strength is greater than 0,and the contribution rate to compressive strength is more significant.Micro analysis shows that quartz powder,as an inert material,can not improve the matrix strength by exerting the chemical activity effect under certain curing conditions,but it can indirectly affect the chemical activity effect of other admixtures and affect the matrix strength.