Utilization of steel slag, iron tailings and fly ash as aggregates to prepare a polymer-modified waterproof mortar with a core-shell styrene-acrylic copolymer as the modifier

Using Poly(styrene-co-hydroxyethyl methacrylate) (P(St-co-HEMA)) microsphere with a core-shell structure as the modifier, a new polymer-modified waterproof mortar was developed with steel slag, iron tailings and fly ash as aggregates. Effects of cement-aggregate ratio, polymer-cement ratio and defoamer-cement ratio on performances of this mortar were investigated. The factor design was used to determine the optimal conditions: polymer-cement ratio, 12 wt.%; cement-aggregate ratio, 1:2.5; defoamer-cement ratio, 0.8 wt.%. The product conformed to Chinese norms. Furthermore, the mortar with P(St-co-HEMA) as the modifier gave better mechanical properties and water resistance compared to those with commercial ethylene-vinyl acetate copolymer (EVA) and styrene-acrylic copolymer (SAE) as modifiers. Microstructures of these polymer-modified mortars were compared and discussed.