建筑垃圾再生骨料吸水性能改善试验研究

Research on Modifying Water Absorption of Construction Waste Recycled Aggregate

建筑垃圾再生骨料较高的吸水率限制了其广泛应用。对再生骨料进行表面改性,使其吸水率与天然材料接近,是提高建筑垃圾资源化利用的一条技术途径。以球磨微损破碎再生骨料为研究对象,采用稀盐酸浸泡、化学浆液和水玻璃溶液浸泡三种表面改性处理方法,结果表明:盐酸浓度为2%,浸泡时间为60 min,再生骨料吸水率为2.97%,较未处理的降低了24.6%;采用硅酸盐水泥浆+10%硅粉,水胶比为0.8,浸泡时间为5 min,再生骨料的吸水率为2.42%,较未处理的降低了38.6%;水玻璃溶液浓度为5%,浸泡时间为5 h,再生骨料吸水率为2.11%,较未处理的降低了46.4%。三种方法均能有效改善再生骨料吸水性能,综合考虑处理效率,采用硅酸盐水泥浆+10%硅粉处理效果最好。

Construction waste recycled aggregates usually have high water absorption rate that limits its wide application. Surface modifying treatment on recycled aggregates to reduce its water absorption rate is a technological way to improve construction waste resource utilization. Dilute hydrochloric acid,grout and sodium silicate were adopted for surface modification of micro-damage broken recycled aggregates. The results show that water absorption rate of recycled aggregates was 2. 97%,2. 42%,2. 11%,and reduced by 24. 6%,38. 6% 46. 4% than that of the untreated one when surface modification was 2% hydrochloric acid with 60 min soak time,Portland cement + 10%silicon powder with water/cement ratio of 0. 8 and 5 min soaking time,and 5% sodium silicate solution with 5h soaking time,respectively. All three methods could improve the water absorption performance of recycled aggregate effectively and Portland cement + 10% silicon powder was best when considering comprehensive treatment efficiency.