基于随机多边形骨料再生混凝土抗氯离子侵蚀研究

Research on Chloride Resistance of Recycled Concrete Based on Random Polygonal Aggregate

基于氯离子扩散模型和骨料级配理论,采用PYTHON语言和COMSOL软件构建再生混凝土随机多边形骨料细观计算模型,并结合已有试验结果验证模型有效性,开展新老砂浆扩散系数、老砂浆厚度及再生骨料取代率等不同工况下再生混凝土抗氯离子侵蚀计算分析,研究氯离子在再生混凝土内部的扩散规律及各细观组分等关键因素对再生混凝土抗氯离子侵蚀的影响规律。结果表明,模拟结果与试验结果吻合较好,该方法能较好地模拟氯离子在再生混凝土内部的扩散过程;再生混凝土氯离子扩散浓度与深度的关系曲线呈现不连续性特征;随着新老砂浆扩散系数的增加,混凝土内氯离子浓度逐渐增大;再生混凝土抗氯离子侵蚀能力随老砂浆厚度、再生骨料取代率的增加而降低。

Based on the chloride ion diffusion model and aggregate gradation theory,the mesoscopic model of recycled concrete random polygonal aggregate was constructed using PYTHON and COMSOL.The validity of the model was verified by the existing experimental results.The calculation and analysis of the chloride ion erosion resistance of recycled concrete under different working conditions such as the diffusivity of new and old mortar,the thickness of old mortar and the replacement ratio of recycled aggregate was carried out.And then the diffusion law of chloride ion in recycled concrete and the influence law of critical factors on the chloride ion erosion resistance were studied.The results show that the simulation results are close to the experimental values,and the method can better simulate the diffusion of chloride ions in recycled concrete.The relationship curve between chloride concentration and depth shows discontinuous characteristics.With the increase of diffusion coefficient of new and old mortar,the chloride ion content increases gradually.The chloride ion erosion resistance of recycled concrete decreases with the increase of the thickness of old mortar and the replacement ratio of recycled aggregate.