二氧化碳矿化养护加气混凝体砌块性能影响因素模型构建及分析研究OA

To achieve the resource utilization of coal-fired solid waste and carbon dioxide,aerated concrete blocks were prepared using coal power solid wastes as the main raw materials in this paper.A numerical model of the carbon sequestration rate and compressive strength of the aerated concrete in relation to curing temperature,curing time,and curing pressure was constructed based on a multi-objective optimization response surface method,and the reliability and applicability of the model were verified.The results show that calcium carbonate is the main product of CO2 mineralisation curing.Increasing curing pressure enlarges the particle size of calcium carbonate crystals and induces microcracks at product interfaces;as curing temperature rises,the inert mullite in concrete begins to participate in reactions,yielding calcium carbonate with higher crystallinity and denser product interfaces.Mineralized products can fill nanoscale pores inside aerated concrete,effectively improving its mechanical properties.When the curing pressure was 0.1 MPa,temperature was 65℃ and duration was 2 hours,the 7-day compressive strength reaches 3.53 MPa,rising by 35.8% compared with natural curing.The performance prediction model reveals that the aerated concrete achieves the optimal comprehensive performance with the maximum compressive strength and relatively high carbon sequestration rate at curing pressure of 0.53 MPa,temperature of 56.5℃ and curing time of 119 minutes,with corresponding theoretical values of 3.69 MPa and 8.4%.The actual measured values are 3.63 MPa and 8.22%,with relative errors of 1.6% and 2.1% respectively,proving the favorable reliability and adaptability of the established model.