再生粗骨料混凝土碳化分析的多场耦合模型及验证

Multi-field coupled model and its verification for carbonation analysis of recycled coarse aggregate concrete

再生粗骨料混凝土的碳化是一个复杂的物理扩散和化学反应过程,其分析和预测较为困难。鉴于此,基于再生粗骨料混凝土的碳化机理,结合再生粗骨料混凝土中CO_2的扩散定律和可碳化物质的质量守恒定律,综合考虑再生粗骨料混凝土中CO_2的有效扩散系数、碳化反应速率系数、可碳化物质的量、再生粗骨料的表面附着砂浆等重要参数的影响,建立了再生粗骨料混凝土碳化分析的多场耦合模型,并通过试验数据验证了模型的有效性和适用性。

Carbonation of recycled coarse aggregate （RCA） concrete was a complicated physical diffusion and chemical reaction process, which was difficult to analyze and predict. According to the carbonation mechanism of the RAC concrete, a multi-field coupled model for carbonation analysis of the RCA concrete was developed by combining the diffusion rule of CO2 within the RCA concrete with the conservation law of mass for the carbonatable substances. The proposed model adopted effective diffusion coefficient of CO2, coefficient of carbonation reaction rate, amount of carbonatable substances and adhesive mortar of the RCA as major control parameters. Efficiency and applicability of the proposed model were validated by comparing with experimental data.