葡萄糖酸钠对萘系减水剂在水泥表面吸附的影响

研究了葡萄糖酸钠对掺萘系减水剂的水泥净浆流动度和凝结时间的影响,葡萄糖酸钠的掺入增加了浆体的流动度和凝结时间.采用紫外-可见光分光光度计和Zeta电位仪,分别测试了水泥颗粒对萘系减水剂的吸附量及水泥颗粒的电位.结果表明,吸附量随着减水剂掺量的增加而增加.减水剂和葡萄糖酸钠在水泥表面存在竞争吸附,葡萄糖酸钠的掺入抑制了减水剂的吸附；但减水剂和葡萄糖酸钠同时吸附在水泥表面增加了水泥表面电位,延缓了水泥水化.

EFFECTS OF SODIUM GLUCONATE ON ADSORPTION FOR NAPHTHALENE-BASED SUPERPLASTICIZER ON CEMENT SURFACE

The effects of sodium gluconate(SG) on fluidity and setting time of pastes added naphthalene-based superplasticizer(NS) were studied and fluidity and setting time of the pastes increased as addition of sodium gluconate.The adsorption amounts,electrokinetic properties,intensity of hydration products were tested using ultraviolet spectrophotometer and Zeta potential meter.The results showed that adsorption amount increased with the addition of superplasticizer.There existed a competitive adsorption on the cement particles between NS and SG,adsorption of superplasticizer was inhabited by the addition of sodium gluconate;However,NS and SG adsorbing on the surface of cement particles led to a higher potential compared to the only NS mixed with cement at the same dosage,and the hydration of cement slowed down.