Effects of carbon-sequestering coral aggregate on pore structures and compressive strength of concrete  

作　　者：Renjie Mi Yifei Wang Tao Yu Wengui Li 

机构地区：[1]Department of Civil and Environmental Engineering,The Hong Kong Polytechnic University,Hong Kong,China [2]School of Civil and Environmental Engineering,University of Technology Sydney,Sydney,NSW 2007,Australia

出　　处：《Low-carbon Materials and Green Construction》2023年第1期263-272,共10页低碳材料与绿色建造（英文）

基　　金：support received from the Hong Kong Research Grants Council(Project No:T22-502/18-R);The Hong Kong Polytechnic University(Project ID:P0039974 and 1-W18N).

摘　　要：CO_(2)sequestration/storage shows considerable impacts on the pore structures and compressive strength of concrete.This paper presents a study in which coral aggregates were presoaked in Ca(OH)_(2) slurries with different solid-to-liquid ratios(i.e.0.2,0.4,and 0.6 g/mL)followed by accelerated carbonation.The effects of CO_(2)sequestration on the particle size distribution,cylinder compressive strength,water absorption,and apparent density of coral aggregate were investigated.The evolution of pore structures in coral aggregate concrete after CO_(2)sequestration was also studied.Additionally,the effect of CO_(2)sequestration on the development of compressive strength of coral aggregate concrete was explored.The results showed that CO_(2)sequestration affected the properties of coral aggregate.Moreover,the porosity of CaCO_(3) formed by CO_(2)sequestration was the highest in the concrete.With the increase of solidto-liquid ratio,the porosity of cement pastes and the CaCO_(3) increased,and more big pores existed in the cement pastes and CaCO_(3).Furthermore,the compressive strength of coral aggregate concrete when the solid-to-liquid ratio was 0.2 g/mL increased compared with that before CO_(2)sequestration,but the compressive strength reduced when the ratio increased to 0.6 g/mL.二氧化碳封存对混凝土的孔结构和抗压强度有较大影响。本文首先将珊瑚骨料分别浸泡在固液比为0.2、0.4和0.6 g/mL的氢氧化钙悬浮液中,然后将浸泡后的骨料加速碳化。其次,研究了二氧化碳封存对珊瑚骨料的粒径分布、筒压强度、吸水率和表观密度的影响。再次,研究了二氧化碳封存后珊瑚骨料混凝土的孔结构演变。最后,探讨了二氧化碳封存对珊瑚骨料混凝土抗压强度发展的影响。结果表明,二氧化碳封存影响了珊瑚骨料的性能。其次,在混凝土中,通过二氧化碳封存形成的碳酸钙的孔隙率最高。随着固液比的增大,水泥基体和该碳酸钙的孔隙率逐渐增大,且水泥基体和该碳酸钙中存在更多的大孔。最后,当固液比为0.2 g/mL时,珊瑚骨料混凝土的抗压强度较二氧化碳封存前有所提高,但当固液比增加到0.6 g/mL时,其抗压强度有所降低。

关 键 词：CO_(2)sequestration Coral aggregate concrete Compressive strength Pore structures 

分 类 号：TU528[建筑科学—建筑技术科学]