超缓释型聚羧酸减水剂在不同类型混凝土中的应用

Application of ultra retarded-releasing polycarboxylate superplasticizer in different concretes

采用异丁烯醇聚乙烯醚(HPEG)、丙烯酸、不饱和酯等,在双氧水-VC引发体系下,常温制备了一种超缓释型聚羧酸系减水剂(SR-1)。在低坍落度混凝土、机制砂混凝土及高流态混凝土中的应用结果表明,SR-1具有优异的缓释性能和良好的适应性,可改善低坍落度混凝土的保坍、减少高含泥/含粉量混凝土的坍损并实现高远程泵送混凝土的长时保坍。此外,SR-1对混凝土凝结时间和强度无不利影响。

In this paper, a novel ultra retarded-releasing polycarboxylate superplasticiser was prepared by the hydrosen peroxide-VC initiator system at room temperature using polyisobntylene alcohol（HPEG）,acrylic acid,acrylamide （AM） and unsaturated ester,named SR-1. The application results in low-slump concrete,machine-made sand concrete and high-fluid concrete show that SR-1 has excellent sustained-release properties and good adaptability,which can effectively solve the slump retention of the low- slump concrete,reduce the slump loss of high powder content of concrete and ensure long--distance pumping concrete long-term retention. In addition,SR-1 has no adverse effect on the setting time and strength of concrete.