地铁衬砌混凝土耐久性能试验研究

Experimental study on durability of subway lining concrete

由于地铁工程投资大、使用年限长,导致地铁衬砌混凝土的耐久性问题尤为重要.针对陆域地段和海域地段所使用的衬砌混凝土,在满足施工泵送性能和力学性能的前提下,重点研究了不同胶凝材料体系对地铁衬砌混凝土的抗氯离子渗透、收缩和碳化等耐久性能的影响.结果表明,在相同强度等级时,随着胶凝材料中矿物掺和料掺量的增加,地铁衬砌混凝土的氯离子迁移系数和碳化深度均逐渐增大,但收缩率显著降低;综合考虑地铁工程的社会效益和经济效益,陆域地段地铁衬砌混凝土的矿物掺和料掺量可选用50%,海域地段地铁衬砌混凝土的矿物掺和料掺量宜控制在40%以内.

It is known that the durability of subway lining concrete is very important in a large investment and long service life.Therefore,this paper focuses on the effect of different cementing material systems on the durability of lining concrete used in the land and sea areas,such as chloride penetration,shrinkage and carbonation under the premise of meeting the pump performance and mechanical properties.The results show that with the increase of mineral admixture in cement materials,the chloride migration coefficient and carbonation depth of subway lining concrete increased gradually,but the shrinkage rate decreased significantly at the same strength grade.To the social and economic benefits of the subway project,the mineral admixture content of the subway lining concrete can be in 50%in the land area,and in the sea area it will be controlled within 40%.