Mechanical properties of nano-SiO2 and fly ash composite modified SAP internal curing concrete

In practical applications, Super absorbent polymers (SAP) can have certain adverse effects on concrete. Incorporation of SAP could lead to changes in the pore structure, thereby affecting strength. At the same time, SAP could also present cost challenges. To address these issues, a specific modifier can be incorporated into the SAP internally curing concrete. In this paper, the mechanical properties of nano-SiO 2 and fly ash composite modified SAP internal curing concrete were investigated. The mechanical properties of the composite modified SAP were reflected through compressive strength and tensile strength tests as well as porosity mutual verification. The results indicate that nano-SiO 2 and fly ash increase the strength of the modified SAP internal curing concrete and reduce the porosity. When the maximum content of nano-SiO 2 reaches 3 %, the modification effect is more favourable. Under the combined effect of nano-SiO 2 and fly ash, both the strength and porosity of SAP internal curing concrete are improved.