纳米SiO2对不同孔隙率下透水混凝土性能的影响

采用体积法设计孔隙率分别为15%、20%、25%的透水混凝土,研究了纳米SiO2(NS)对透水混凝土抗压强度、透水系数的影响规律。总结了不同孔隙率下透水混凝土的破坏形式,并分析了破坏机理。结果表明:随着NS掺量的增加,三种孔隙率下透水混凝土的抗压强度均呈先增加后减少的趋势,在NS掺量为1.0%时,抗压强度都达到最大值;NS对透水混凝土7 d抗压强度的提升效果比28 d更显著;随着孔隙率逐渐增大,NS对透水混凝土抗压强度的改善效果逐渐增强,而对透水系数的提升效果逐渐减弱;从透水混凝土的破坏形式上来看,随着孔隙率逐渐增大,掺入适量NS的透水混凝土,其骨料处断裂的现象相较未掺NS时逐渐增多。

The Effect of Nano-SiO2 on Propereies of Pervious Concrete Under Different Porosities

The pervious concrete with porosity of 15%,20%and 25%was designed by using the volume method,and the effect of nano-SiO2(NS)on the compressive strength and hydrological permeability of pervious concrete under three porosities was studied.The failure modes and mechanism of pervious concrete under different porosities were summarized and analyzed.The research results show that with the increase of the NS content,the compressive strength of pervious concrete under the three porosities first increases and then decreases,and the compressive strength reaches the maximum when the NS content is 1.0%.The improvement effect of 7 d compressive strength of pervious concrete is more significant than that of 28 d.As the porosity gradually increases,the improvement effect of NS on compressive strength of pervious concrete gradually increases,but the effect of increasing the hydrological permeability gradually decreases.From the terms of the damage form,as the porosity gradually increases,the fracture phenomenon of the pervious concrete which mixed with an appropriate amount of NS will gradually increase than the case without NS.