Internal Curing Properties of Acrylamide Type SAP Loaded with Nano Silica
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.
nano silicasuperabsorbent polymermortarautogenous shrinkagedrying shrinkagemechanical propertydegree of hydrationmicrostructure