沸石减水保塑剂的特性与工程应用

以天然沸石超细粉吸附高效减水剂,制得沸石减水保塑剂。沸石减水保塑剂可用于普通混凝土、高性能混凝土及超高性能混凝土,使混凝土流动性增大,并能控制流动性的经时变化;这主要是由于在混凝土中它能缓慢被释出,从而维持水泥粒子对减水剂的吸附量,使水泥粒子表面具有较稳值的Zeta电位,使水泥浆常处于分散状态。在超高性能混凝土中,它还能降低新拌混凝土的粘度,便于泵送施工。沸石减水保塑剂掺入混凝土中还能改善硬化混凝土的结构,提高混凝土的强度。

Absorption and desorption of superplasticizer by natural zeolite powder were investigated,and a zeolite plastic-keeping water reducer with natural zeolite powder as a carrier was produced. The addition of zeolite superplasticizer in concrete, the HPC and UHPC can increase their fluidity and slump, while the loss of fluidity and slump are effectively controlled. The causes are mainly that, the superplasticizer can be released gradually in the concrete from absorpted surface of zeolite, that will maintain the concentration of superplaticizer at the surface of cement particles, so that can maintain the surface zeta potential of cement particles and can keep the dispersing state of cement paste. It can also decrease the viscosity of fresh concrete for easy concreting of UHPC by pumping.The zeolite plasticizer can also improve the structure and increase the strength of concrete.