Research on the Performance of Recycled-Straw Insulating Concrete and Optimization Design of Matching Ratio

Abstract

Construction solid waste and agricultural waste, as renewable resources, have gained increasing attention recently. This research aims to explore the mechanical and thermal properties of recycled-straw insulating concrete commonly made with construction waste and straw in northern Fujian, which can provide useful suggestions for the practical use of recycled-straw insulating concrete. The effects of recycled coarse aggregate, fly ash, and straw on the mechanical and thermal properties of recycled-straw insulating concrete were investigated by orthogonal tests. The results of the orthogonal tests were optimized by the total efficacy coefficient method to obtain the optimal mix ratio of recycled-straw insulating concrete. Combined with the finite element analysis software ANSYS Workbench, the heat transfer performance of the recycled-straw insulating concrete walls was analyzed to simulate the insulation performance of the walls. The compressive strength of the recycled-straw insulating concrete with the optimal ratio was found to be 30.93 MPa, and the thermal conductivity was 0.5051 W/(m·K). The steady-state thermal analysis of the recycled-straw insulating concrete wall and the plain concrete wall was carried out by finite element software, and the simulation results showed that the insulation performance of the recycled-straw insulating concrete walls was improved by 145% compared with the plain concrete wall. These results indicate that the recycled-straw insulating concrete wall has better thermal insulation performance and can be applied to building envelopes to save heating costs in winter and reduce carbon dioxide emissions, which has significant economic and environmental significance for areas with low outdoor temperatures in winter and long heating periods.