无机预处理再生粗骨料的性能研究

Study on Property of Recycled Coarse Aggregate Pretreated with Inorganic Materials

目的利用无机预处理法处理村镇建筑垃圾,使处理后的建筑垃圾能作为再生粗骨料应用到混凝土中.方法用水泥净浆和水泥砂浆对再生粗骨料进行表面预处理,测试其压碎指标和吸水率,通过正交试验分析选出最优方案.结果预处理后再生粗骨料的压碎指标和吸水率比未经处理的小,当砂浆配比为1∶2∶2时,压碎指标为16.2%,吸水率为4.57%.通过扫描电镜观察再生粗骨料的界面过渡区,发现涂浆层不与骨料本身反应.结论通过正交试验分析,水泥砂浆预处理方法要优于水泥净浆预处理法,水泥净浆预处理的最佳组成为:水灰比0.45,涂浆量为35%,早强剂掺量为2%;水泥砂浆预处理的最佳组成为:砂浆配比1∶2∶2,涂浆量为35%,早强剂掺量为2%.

In this paper, we intend to illustrate that rural building wastes working as recycled aggregate are able to be applied to concrete after being pretreated with inorganic materials. Surface pretreatment is processed with cement paste and cement mortar, then its crushing value and water absorption are tested and optimum scheme is selected through analysis of orthogonal test. The result shows that crushing value and water absorption rate of recycled aggregate pretreated are lower than those without pretreatment. Crushing value and water absorption have respective lowest value of 16.2% and 4.57% when mortar mixing rate is designed as 1：2： 2. It was found that there was no reaction between coating layer and aggregate through SEM studies on interracial transition zone. It can be found through orthogonal test that in term of pretreatment method of cement paste and cement mortar, the former one is better. The optimum composition of cement paste pretreatment is： water cement ratio 0.45, coating capacity 35 % , mixing amount of early strength agent 2% ; The optimum composition of cement mortar pretreatment is： mortar mixing rate 1 ： 2： 2, coating capacity 35%, mixing amount of early strength agent 2%.