Analysis of the Performance of Recycled Insulation Concrete and Optimal Mix Ratio Design Based on Orthogonal Testing

Construction and agricultural waste recycling have gained more and more attention recently as renewable resources. Straw and construction waste, both of which are widespread in northern Fujian, were investigated in this research. The orthogonal test was used to investigate the effects of recycled aggregate, straw, and glazed hollow beads on the mechanical and thermal properties of recycled insulation concrete. The influence of different factors on the macroscopic characteristics of recycled insulation concrete was examined using scanning electron microscopy (SEM). The optimal mix proportion for recycled insulation concrete that satisfies mechanical performance standards and provides superior insulation performance was then determined using the total efficacy coefficient method. According to the research findings, the heat conductivity of recycled insulation concrete decreases as its dried density decreases. A 100% recycled coarse aggregate replacement rate, 1% straw content, and 10% glazed hollow beads replacement rate are the optimal mix ratios for recycled insulation concrete. With a compressive strength of 20.98 MPa, a splitting tensile strength of 2.01 MPa, a thermal conductivity of 0.3776 W/(m·K), and a dry density of 1778.66 kg/m³, recycled insulation concrete has the optimal mix ratio. Recycled insulation concrete is a novel form of eco-friendly, energy-saving concrete that aims to achieve low-carbon energy savings and sustainable development by combining resource recycling with building energy savings to realize the recycling of solid waste resources, which has significant environmental, social, and economic benefits and broad market application potential.