Effects of aggregate gradation and polymer modifiers on properties of cement-EPS/vitrified microsphere mortar

Cement-EPS/vitrified microsphere (VM) mortar (shortened as CEV mortar) was prepared by sulphoaluminate cement, EPS and VM aggregates. Moreover, the effects of polymer modifiers (i.e. air-entraining agent, emulsified asphalt and redispersible latex powder) on the mechanical properties, water absorption and drying shrinkage of CEV mortar were investigated. The experimental results showed that the optimal ratio of R-VM (VM to total insulation aggregates ratio) was 0.65. In addition, the compressive strength of CEV mortar was 1.65 MPa, dry density was reduced by 25% to 350 kg/m(3), and thermal conductivity was lowered by 30% to 0.065 W/(m k) when the dosage of air-entraining agent was 0.2%. Furthermore, compared with redispersible latex powder, emulsified asphalt could make CEV mortar with lower water absorption, lower pressure off ratio, lower drying shrinkage and more stable softening coefficient. But redispersible latex powder could increase the viscosity of the cement paste to improve mechanical properties. (C) 2014 Elsevier Ltd. All rights reserved.