大掺量再生粗骨料混凝土耐久性研究

Research on Durability of High Volume Recycled Coarse Aggregate Concrete

研究了再生粗骨料掺量及胶凝材料类型对再生混凝土耐久性能的影响,测试了5种类型再生混凝土的动弹性模量、碳化深度与氯离子迁移系数指标,并进行了分析。研究结果表明,增大再生粗骨料掺量降低了再生混凝土的抗冻性能,但掺量不超过50%时,可基本满足其抗冻性能要求。同时,掺加矿物掺合料能增强大掺量再生粗骨料混凝土的抗氯离子渗透性能,但却降低了其抗碳化性能与抗冻性能,因此再生粗骨料掺量要根据使用环境进行综合考虑。

The impact of the content of recycled coarse aggregate and the type of cementitious material on the dura-bility of recycled concrete was investigated. The dynamic elastic modulus, carbonation depth and chloride ion migration coefficient of five types of recycled concrete were tested and analyzed. The results show that the frost resistance of recycled concrete reduces with the increase of recycled aggregates amount. When the amount does not exceed50%, it can basically meet the requirements of frost resistance. Meanwhile, adding mineral admixtures can enhance the resistance to chloride ion penetration,but reduce its resistance to carbonation and frost. Therefore, it should be considered comprehensively according to the application environment.