Performance of alkali-activated cementitious composite mortar used for insulating walls

Abstract There are large volumes of fly ash, slag and silica fume produced in the world. The waste disposal to the landfill is problematic and causes many environmental issues. The objective of this work is to demonstrate how fly ash, slag and silica fume can be used to produce alkali-activated cementitious composite mortar (AACCM) used for insulating walls. The combination of both polymers and alkali-activated cementitious material (AACM) made from fly ash, slag powder and silica fume enables a full composite action. The polymers include Methyl Cellulose Ether (MCE), Polyvinyl Alcohol (PA), and Calcium Formate (CF). The thermal insulating aggregates were cemented into insulating mortar under the composite action. The ratio of fly ash, slag powder and silica fume in the AACM is 5:5:1. The experimental results show that the compressive strength , dry density and thermal conductivity of cement-based thermal insulation mortar (TIM) decrease significantly with the increase of MCE content. MCE has an obvious air-entraining effect on cement-based mortar. When the percentages of MCE, PA, and CF are 1%, 1.6% and 1%, the compressive strength, dry density and thermal conductivity of the TIM are 0.50 MPa, 398.7 kg/m 3, and 0.0932 w/(m·k) respectively. MCE has a weak air-entraining effect on AACM. When the percentages of MCE, PA, and CF are 3%, 2% and 1%, the compressive strength, dry density and thermal conductivity of the TIM are 0.28 MPa, 328.7 kg/m3, and 0.0775 w/(m·k) respectively. The simulation results of heat transfer performance show AACCM can be used for insulating walls.