Experimental Study on Thermal Conductivity of Concrete for Building Reinforced Concrete Composite Wall

In order to determine the thermal conductivity of the concrete for building reinforced concrete composite wall, the fine-aggregate concrete for the thermal insulation layer and the composite concrete for the reinforced concrete wall were made from the ordinary concrete by in-situ wet-sieving techniques. The compositions of these three kinds of fresh concrete were determined, which expressed by the volume fraction of crushed stone and the volume ratio of crushed stone to mortar. The thermal conductivity of concrete was measured by the one-dimensional steady heat flow meter. Based on the tests, the changes of thermal conductivity of concrete affected by the volume fraction of crushed stone and the volume ratio of crushed stone to mortar were analyzed. The correlation analysis shows that the correlation of the thermal conductivity is better with the volume ratio of crushed stone to mortar. The formula for forecasting the thermal conductivity of concrete is proposed.