碳化处理后再生混凝土抗盐侵蚀性能研究

RESEARCH ON SALT CORROSION RESISTANCE OF RECYCLED AGGREGATE CONCRETE AFTER CARBONATION TREATMENT

通过改变碳化温度、相对湿度和碳化时间以确定再生骨料最佳碳化工艺参数;选取天然骨料、未碳化再生骨料和三种碳化骨料制备混凝土,探究碳化再生骨料对再生混凝土氯盐和硫酸盐侵蚀性能的影响规律。结果表明:碳化后再生骨料表观密度、吸水率和压碎值显著提升,确定的最佳碳化工艺参数为温度20℃、相对湿度55%和碳化时间24 h;相比再生混凝土,碳化骨料混凝土的抗氯离子渗透性能提升了5.1%~22.1%,但低于普通混凝土;碳化再生骨料的抗硫酸盐侵蚀性能不仅优于再生混凝土,而且高于普通混凝土。

By changing the carbonation temperature,relative humidity and carbonation time,the best carbonation process parameters of recycled aggregate were determined;on this basis,natural aggregate,un-carbonized recycled aggregate and three kinds of carbonized aggregate were selected to prepare concrete.The influence of carbonation of recycled aggregate on the performance of recycled concrete in the corrosion of chloride and sulfuric acid was explored.The results showed that the apparent density,water absorption rate and crushing value of recycled aggregate increased significantly after carbonation.The optimal carbonation process parameters were as follows:temperature 20℃,relative humidity 55%and carbonation time 24 h.Compared with recycled concrete,the chloride ion penetration resistance of carbonated aggregate concrete was improved by 5.1%~22.1%,but lower than that of ordinary concrete.Unlike the chloride ion resistance,the sulphate attack resistance of carbonated recycled aggregate concrete was not only better than recycled concrete,but also higher than ordinary concrete.