纳米二氧化硅负载丙烯酰胺型SAP内养护性能研究OA北大核心CSTPCD

In this paper,nano silica(NS)loaded acrylamide-type superabsorbent polymer(SAP)was designed and prepared,and the influence of different NS loadings of SAP on the autogenous shrinkage,drying shrinkage,and mechanical properties of mortar were investigated.The results showed that acrylamide-type SAP could completely eliminated the autogenous shrinkage of mortar,and the inhibition effect of NS-loaded SAP on autogenous shrinkage decreased with the increase of NS loading,but still remained above 80％.The introduction of SAP and additional water increased the drying shrinkage of mortar,but with the increase of NS loading,NS-loaded SAP had a positive effect on mitigating the drying shrinkage.The introduction of SAP and additional water reduced the mechanical properties of the mortar,but with the increase of NS loading,the NS-loaded SAP significantly improved the mechanical properties of mortar.In particular,SAP loaded with 50％(relative to the mass fraction of acrylamide)NS had the least effect on the mechanical properties of the mortar,with only a 5.6％and 2.2％loss in compressive and flexural strength of the specimens at 28 d.TG and BSE results showed that the degree of hydration of the cured specimens within NS-loaded SAP increased significantly with the increase of NS loading,and the microstructure was significantly improved.