Effects of Polyacrylamide and Water Reducer on Hydration of Cement
The effect of polyacrylamide(PAM)on cement hydration and performance limits the large-scale application of manufactured sand.In this paper,the effects of the interaction of three typical polyacrylamides(PAM)with polycarboxylate superplasticizer(PCE)and naphthalene superplasticizer(FDN)on the early performance of cement pastes were investigated.The study finds that the interaction of PAM with PCE and FDN significantly enhances the shear stress of cement paste,and negatively affects its fluidity.The bridging effect of PAM attenuates the electrostatic repulsive effect of PCE and FDN,and binds some of the reactive free water,which reduces the hydration release heat and hydration product generation of cement paste.With the increase of PAM doping,the PAM-PCE system mainly increases nanopores,but the effect on strength is small,while the increase in pores of the PAM-FDN system is concentrated in micrometer pores,and the strength decreases significantly.Among the three PAM,the interaction of cationic PAM(APAM)with PCE and FDN significantly inhibits the generation of cement hydration products.
万方数据
维普
