三聚磷酸钠在水泥颗粒表面的吸附行为及缓凝剂机理  

Adsorption Behavior on Cement Particles and Retarder Mechanism of Sodium Tripolyphosphate

作　　者：杨平[1] 

机构地区：[1]湖南工程职业技术学院土木工程系,长沙410151

出　　处：《硅酸盐通报》2013年第6期1212-1216,共5页Bulletin of the Chinese Ceramic Society

基　　金：湖南省高等学校科学研究项目(10C0108)

摘　　要：本文通过测定不同三聚磷酸钠掺量下水泥颗粒的ζ电位,三聚磷酸钠的吸附量、钙离子浓度变化,分析了三聚磷酸钠在水泥颗粒表面的吸附特性,并结合水化热分析、水化产物的XRD、SEM分析,研究了三聚磷酸钠的缓凝机理。结果表明:三聚磷酸钠易与钙离子形成络合物,并吸附于水泥颗粒表面,当掺量为0.05%时,其吸附率可达到97%,当掺量为0.4%时,其吸附率可达到89%;形成的络合物[CaP3O10]3-存在于水泥颗粒表面,改变水泥颗粒表面电性能,同时抑制钙离子的溶出,降低液相中钙离子浓度,延迟水化放热,延缓水化产物形成,当掺量超过0.2%时,1 d水化产物中无明显的CH。In this paper,ζ-potential,adsorption amount of sodium tripolyphosphate（STPP）,calcium ion concentration with different dosage of STPP has been discussed to analyse adsorption properties of STPP on surface of cement particles.Retarding mechanism of STPP has been discussed by the heat of hydration analysis,XRD,SEM.The result shows that STPP and calcium ions can easily formed complexes,which adsorb on surface of cement particles;when the content is 0.05%,adsorption rate can reach 97%;when the content is 0.4%,adsorption rate up to 89%;the present of complexes [CaP3O10]^3-on surface of cement particles change the ζ-potential and inhibit the dissolution of calcium at the same time;it reduces the concentration of calcium ions in the liquid phase,and delay heat of hydration and formation of hydration products;when the dosage of STPP is more than 0.2%,there is little CH in hydration product of 1 d.

关 键 词：吸附量 吸附率 Ζ电位 水化热 钙离子浓度 

分 类 号：TU528[建筑科学—建筑技术科学]