不同性能再生骨料的CO_(2)强化及其对混凝土抗压强度的影响  

CO_(2) strengthening of recycled aggregate with different properties and its effect on compressive strength of concrete

作　　者：黄靓麟 黄君宙 田家硕 应敬伟[1] HUANG Lianglin;HUANG Junzhou;TIAN Jiashuo;YING Jingwei(College of Civil Engineering and Architecture,Guangxi University,Nanning 530004,China)

机构地区：[1]广西大学土木建筑工程学院,广西南宁530004

出　　处：《混凝土》2022年第6期94-97,102,共5页Concrete

基　　金：国家自然科学基金项目(51768005);广西自然科学基金项目(2018GXNSFAA281333)。

摘　　要：为研究碳化对不同性能再生粗骨料(RCA)的影响,将不同水灰比的母体混凝土破碎筛分后制得RCA,并使用高浓度CO_(2)强化RCA以得到碳化后的再生粗骨料(CRCA)。通过试验测试了碳化前后RCA的物理特性,使用RCA和CRCA分别浇筑了再生混凝土,并进行了抗压强度测试。结果表明:随着母体混凝土水灰比的增加,RCA和CRCA的吸水率与压碎指标均有所增加。碳化后,再生骨料的吸水率明显降低,级配无明显变化,总孔隙率降低且部分有害孔转为无害孔。与天然混凝土相比,使用RCA或CRCA浇筑的再生混凝土,抗压强度均有所降低。RCA来源的母体混凝土水灰比为0.4、0.5、0.6时,再生混凝土的抗压强度分别降低了11.0%、19.5%、40.3%。与使用RCA浇筑的再生混凝土相比,当母体混凝土水灰比为0.4、0.5、0.6时,使用CRCA浇筑再生混凝土的抗压强度分别提高了3.6%、4.7%、16.0%。In order to study the effect of carbonation on recycled coarse aggregate(RCA)with different properties,RCA was prepared by crushing and screening the parent concrete with different water cement ratio,and then carbonized recycled coarse aggregate(CRCA)was obtained by strengthening RCA with high concentration of CO_(2).The physical properties of RCA and CRCA were tested by experiments.Recycled concrete was poured with RCA and CRCA respectively,and the compressive strength was tested.The results show that the water absorption and crushing index of RCA and CRCA increase with higher water-cement ratio of parent concrete.After carbonization,the water absorption rate of RCA decreases obviously,the gradation has no obvious change,and the total porosity decreases,and some harmful pores turn into harmless ones.Compared with natural concrete,the compressive strength of recycled concrete poured with RCA or CRCA is reduced.When the water cement ratio of parent concrete from RCA is 0.4,0.5 and 0.6,the compressive strength of recycled concrete decreases by 11.0%,19.5%and 40.3%.Compared with the recycled concrete poured with RCA,when the water cement ratio of parent concrete is 0.4,0.5 and 0.6,the compressive strength of recycled concrete poured with CRCA is increased by 3.6%,4.7%and 16.0%.

关 键 词：再生粗骨料 CO_(2)强化 物理性能 微观孔隙 抗压强度 再生混凝土 

分 类 号：TU528.041[建筑科学—建筑技术科学]