南水北调某标段全机制砂混凝土配合比试验

摘要

南水北调中线某标段位置较为偏僻,用于混凝土细骨料的天然河砂在当地不易得到,远距离运输既不经济又不环保.为解决混凝土用砂问题,在对机制粗骨料、机制砂级配、水泥、外加剂等各项指标检测合格的基础上,采用不同配合比制配不同强度等级、不同坍落度及抗冻、抗渗性能要求的全机制砂混凝土,对各项指标进行了测试,对灰水比与28 d强度、砂率和各龄期强度、强度随龄期增长等指标进行了探讨.研究结果表明:全机制砂混凝土能达到施工坍落度、可泵性及强度、抗冻、抗渗等各项性能的指标,砂率和胶水比对各龄期强度影响较为明显.用全机制砂混凝土具有经济和环保的双重效益.%One of the south-to-north water diversion project sections is on the remote location. In order to solve the problems of high price and environmental protection induced by natural river sand concrete, the performance of the coarse and fine aggregate, sand gradation, cement, additives and so on were tested. Different strength grade full machine-made concretes with different mix ratio, slump for frost resistance, impermeability and construction performance requirements were made. The relationships of cement-water ratio with 28 d strength, sand ratio with concrete strength in 7 d and 28 d age, strength growth with age were discussed. The results show that the full machine-made sand concrete is qualified in the performance of the construction slump,pump and strength ,frost resistance ,and impermeability.