A study on heat transfer performance of recycled aggregate thermal insulation concrete

Abstract Recycled aggregate thermal insulation concrete can achieve the recycling of resources, meanwhile enhancing energy saving effect for buildings. This functional concrete is a heterogeneous material that has complex internal components. Traditional thermal conductivity prediction models can hard characterize the heat transfer performance exhibited by recycled aggregate thermal insulation concrete. This paper proposes a new thermal resistance testing method to study the effects that the volume fraction of recycled coarse aggregates and glazed hollow beads have on the heat transfer performance of recycled aggregate thermal insulation concrete. Also, a thermal resistance prediction model suitable for recycled aggregate thermal insulation concrete through experimental and simulation analysis is established. Results show that recycled aggregate thermal insulation concrete thermal resistance increases with an increase in volume fraction of recycled coarse aggregate and glazed hollow beads. The deviation between the test results and the results of the random aggregate model is 0.96%. The thermal resistance model can be used to accurately predict recycled aggregate thermal insulation concrete thermal resistance. This research method has a certain theoretical value for research on the heat transfer performance of materials that have high porosity and multiple components inside them.