掺花岗岩石粉对低强水工混凝土强度及微观结构的影响研究

Effect of granite powder on strength and microstructure of low strength hydraulic concrete

本文根据等量替换原则,采取宏观与微观试验相结合的方式,对不同掺量花岗岩石粉的混凝土强度和微观结构进行了研究分析。结果表明:当花岗岩石粉掺量小于10%时,对混凝土的强度具有提升作用,当掺量大于10%后,混凝土的强度逐渐降低;过渡孔以及凝胶孔随掺量的增加呈"升高—降低"两阶段变化特征。毛细孔随掺量呈逐渐减小趋势,大孔随掺量呈"降低—升高"两阶段变化特征。应用研究成果建立起强度、孔隙率、孔隙体积、分形维数之间的拟合关系,可对任意花岗岩石粉掺量下的混凝土强度进行较为准确的预测,具有一定普遍性。

The strength and microstructure of concrete with different amounts of granite powder are studied by means of macroscopic and microscopic tests based on the principle of equivalent substitution.The results show that when the content of granite powder is less than 10%,the strength of concrete is increased,and the strength of concrete is gradually decreased when the dosage is more than 10%.The increase of the transition pore and gel pore is characterized by two stages of"increase-decrease",the capillary pore is decreased with the amount of admixture,and the macropore shows two-stage change characteristic of‘decrease-increase’with the amount of admixture.The fitting relationship among strength,porosity,pore volume and fractal dimension is established through the research results,which can accurately predict the strength of concrete with arbitrary amount of granite powder,and it is universal.