Ca(OH)_(2)预浸泡浓度对碳化增强再生骨料混凝土性能的影响

Effect of calcium hydroxide pre-soaking on the properties of recycled aggregate concrete prepared by accelerated carbonation

将产量逐年递增的建筑固废进行加工,生产再生骨料替代天然骨料,可以消耗建筑固废,减少矿产资源开采。采用CO_(2)加速碳化再生粗骨料,可提高其吸水率和压碎指标,同时还能起到固碳作用,有利于助力碳中和。为了提高碳化效率,将再生粗骨料浸泡于Ca(OH)_(2)溶液进行预处理,并研究不同浸泡浓度对再生粗骨料及其所制备的再生骨料混凝土性能的影响。结果表明:Ca(OH)_(2)溶液浸泡浓度为4 mol/kg时,碳化效果最优,再生粗骨料的吸水率和压碎指标比未处理时,分别提高了10.4%和9.4%,所制备的再生骨料混凝土的28 d抗压强度和劈裂抗拉强度则分别提高了8.4%和18.6%。

The construction and demolition waste with increasing output year by year can be processed to produce recycled aggregate to replace natural aggregate,so as to consume waste and reduce the exploitation of mineral resources.Using CO_(2) accelerated carbonation to strengthen recycled coarse aggregate can not only improve its water absorption and crushing index,but also play a role in carbon fixation,which is conducive to carbon neutralization.In order to improve the carbonation efficiency,the recycled coarse aggregate was pre-soaked in Ca(OH)_(2) solution,and the effects of different soaking concentration on the properties of recycled coarse aggregate and the properties of recycled aggregate concrete were studied.The results showed that the carbonation efficiency was the best when the concentration of Ca(OH)_(2) solution was 4 mol/kg.The water absorption and crushing index of recycled coarse aggregate were increased by 10.4%and 9.4%respectively,then the 28 d compressive strength and splitting tensile strength of recycled aggregate concrete were increased by 8.4%and 18.6%respectively,compared with those without pre-soaking treatment.