矿物掺合料透水混凝土微观结构及性能分析

Microstructure and Performance Analysis of Pervious Concrete with Mineral Admixtures

透水混凝土具有显著的孔隙特征,可有效缓解城市内涝,涵养地下水系。针对透水混凝土由孔隙大导致的抗压强度低等问题,采用矿物掺合料替代部分水泥作胶凝材料,能够实现降低生产成本并提高抗压强度的目的。本文以粉煤灰、矿渣、偏高岭土等固体废弃物为掺合料,通过抗压强度、透水性能测试分析矿物掺合料单掺、复掺、三掺对透水混凝土性能的影响,并探究其水化机理。结果表明:复掺以及三掺体系的透水混凝土力学性能明显优于单掺体系;当三掺体系粉煤灰、矿渣、偏高岭土掺量分别为15%(质量分数,下同)、15%、10%时,透水混凝土性能最佳,抗压强度达22.1 MPa,孔隙率和透水系数分别为14.3%、3.27 mm/s,满足行业标准。

Pervious concrete has significant pore characteristics,which can effectively solve urban waterlogging and conserve underground water systems.In view of the low compressive strength of pervious concrete caused by large pores,mineral admixtures were used to replace part of cement as cementitious materials in order to achieve the purpose of reducing production costs and improving compressive strength.In this paper,using fly ash,slag,metakaolin and other solid wastes as admixtures,compressive strength and water permeability tests were used to analyze the effects of single,double and triple-doped mineral admixtures on the properties of pervious concrete,and explore the hydration mechanism.The results show that the mechanical properties of pervious concrete with double-doped and triple-doped admixture system are significantly better than those of single-doped admixture system.When the content of fly ash,slag and metakaolin in triple-doped system is 15%(mass fraction,the same below),15%and 10%,respectively,the property of pervious concrete is the best,of which the compressive strength is 22.1 MPa,and the porosity and water permeability coefficient are 14.3%and 3.27 mm/s,respectively,meeting the industry standards.