搅拌站废水回收利用对防水混凝土抗渗性的影响

Influences of Wastewater in Concrete Plant on Impermeability of Waterproofing Concrete

将经商品混凝土回收机分离出来的废水,等质量取代自来水配制混凝土,研究了掺入前后和不同掺量对混凝土的凝结时间、工作性能、力学性能和抗渗性能的影响。其结果表明:废水对水泥凝结时间影响较小;随着废水浓度的增大,混凝土的坍落度相对变差,且经时损失更大;废水有利于混凝土的强度发展,提升混凝土抗渗性能,高含量的氢氧化钙有利于矿物掺和料的二次水化,增强混凝土的密实度。

The effect of wastewater in concrete plant on performance of cement-based material, where the content of wastewater and tap water mixture is varied by weight, has been investigated. The setting time, workability, mechanical properties and impermeability are tested. The experimental results show that wastewater has minor effect on the setting time of cement, and the slump of concrete significantly decreases with the increase concentration of wastewater. Meanwhile, they have slump time losing a relatively changed for the worse. On the other hand, wastewater improves the strength and impermeability. The high content of Ca （OH）2 in wastewater is helpful to improve the secondary hydration of mineral admixtures, it can improve the compactness of concrete.