二氧化碳浓度对低钙固碳胶凝材料性能影响及机理研究

Effect of Carbon Dioxide Concentration on Performance of Low-Calcium Carbon Sequestration Cementitious Materials and Its Mechanism

为了实现建材行业的“碳达峰、碳中和”目标,使用工业钙质原料和硅质原料在1350℃制备了一种低钙固碳胶凝材料,研究了不同CO_(2)浓度养护对低钙固碳胶凝材料碳化程度和碳化后性能的影响,并通过X射线衍射(XRD)、傅里叶红外光谱分析(FT-IR)、热重分析(TG)、扫描电子显微镜(SEM)、电子探针(EPMA)等测试手段进行了低钙固碳胶凝材料碳化后的产物分析、微观分析和机理分析。结果表明,随着CO_(2)浓度的提高,低钙固碳胶凝材料的碳化程度和抗压强度显著提高,当CO_(2)浓度为99.99%(体积分数)时,低钙固碳胶凝材料碳化8 h后的抗压强度为132.2 MPa,与CO_(2)浓度为25%时相比,抗压强度提高了260%。

In order to achieve the national strategic goals of“peak carbon dioxide emission and carbon neutrality”in the building materials industry,a type of low-calcium carbon sequestration cementitious materials(LC-CSCM)was prepared by calcining industrial calcareous and siliceous raw materials at 1350℃.The influences of different concentrations of CO_(2) on the carbonation degree and the carbonation hardening performance of LC-CSCM were investigated.XRD,FT-IR,TG,SEM and EPMA were used for the evolution of product analysis,microanalysis and mechanism analysis of carbonated LC-CSCM.The results show that with the increase of CO_(2) concentration,the carbonation degree and the carbonation hardening performance of LC-CSCM increase significantly.When the CO_(2) concentration is 99.99%(volume fraction),the compressive strength reaches 132.2 MPa after 8 h of LC-CSCM carbonation curing;compared with the concentration CO_(2) of 25%,the compressive strength increases by 260%.