Experimental and numerical investigation on innovative masonry walls for industrial and residential buildings

Abstract

This study proposes efficient exterior concrete walls (consisting of blocks, mortars, and plasters) to reduce the heat transfer to or from buildings for minimizing energy consumption due to air conditioning or heating processes. Different blocks were treated by partially or totally replacing coarse and fine aggregates with insulation materials. Mortars and plasters were also treated by partially replacing sand with certain insulation materials. A control block (without treatment) was also produced with three-row rectangular cavities to reduce the effective thermal conductivity. Experimental tests were performed to determine the thermal conductivity of blocks, mortars, and plasters, and to validate a developed three-dimensional model (using ANSYS-Fluent program). The model results showed a substantial increase in model accuracy (about 15%) by involving the estimation of radiation heat transfer in the block cavities. The thermal and economic performance of treated masonry walls showed that the optimal performance was obtained from a wall having volcanic scoria-treated blocks (200-mm thick) and 15% vermiculite-treated mortar (10-mm thick). The thermal performance was enhanced by 15% and 318% (for thermal resistance increase) and 13% and 76% (for heat flux reduction) more than those of the control and market walls, respectively. Adding 15% vermiculite-treated plaster (2 × 15-mm thick) to the wall enhanced the thermal performance remarkably. The total cost of the improved wall (having the highest thermal resistance) was reduced by 1.39 and 3.67 times over the control and market walls (Dhahran, Saudi Arabia), respectively. This improved wall is a promising candidate for exterior walls in residential and industrial buildings.