摘要
本文研究了在搅拌过程中分别掺入固态干冰及气态CO_(2)对水泥砂浆和净浆性能的影响规律,并利用热重和扫描电镜微观测试手段阐明其影响机制。结果表明:在水泥拌合过程中,固态干冰和气态CO_(2)的加入均会引起水泥基材料流动性的劣化,导致胶砂的抗折强度和抗压强度降低;当胶砂比从1∶3提升到1∶2.4时,CO_(2)的水化促进作用得以体现,加入适量的CO_(2)会对水泥胶砂的力学性能起到积极的作用,当CO_(2)加入量为0.3%~0.6%时,胶砂各龄期强度均有明显的提升;当增大CO_(2)加入量时,胶砂各龄期强度的增强效果逐渐降低;添加不同量的干冰与气态CO_(2)后,水泥净浆的固碳量均有不同程度的提升,当CO_(2)的加入量为0.5%时,水泥净浆的净固碳量最高,之后随着CO_(2)加入量的增大,其固碳量不再提升;CO_(2)的加入会与水泥中的C_(3)S、C_(2)S等矿物生成碳酸盐晶体,形成成核点位,加快水泥的水化进程,从而提升胶砂的强度。
This article investigates the effects of adding solid dry ice and gaseous CO_(2)during the mixing process on the properties of cement mortar and net slurry,and elucidates their influencing mechanisms using thermogravimetric and scanning electron microscopy microscopic testing methods.The results indicate that the addition of solid dry ice and gaseous CO_(2)during the cement mixing process can cause deterioration of the flowability of cement-based materials,leading to a decrease in the flexural and compressive strength of the mortar.When the cementation ratio is increased from l:3 to 1:2.4,the hydration promotion effect of CO_(2)can be reflected,and the appropriate amount of CO_(2)will have a positive effect on the mechanical properties of cement mortar.When the amount of CO_(2)is 0.3%~0.6%,the strength of cement sand at each age can be improved obviously.When the amount of CO_(2)added increases,the strengthening effect of the strength of the sand at different ages gradually decreases;after adding different amounts of dry ice and gaseous CO_(2),the carbon sequestration of cement slurry increased to varying degrees.When the amount of CO_(2)added is 0.5%,the net carbon sequestration of cement slurry is the highest.Later,as the amount of CO_(2)added increases,the carbon sequestration no longer did not increase.The addition of CO_(2)will form carbonate crystals with C_(3)S,C_(2)S and other minerals in cement,forming nucleation points,speeding up the hydration process,and thus improving the strength.
出处
《混凝土世界》
2024年第6期32-38,共7页
China Concrete
基金
北京市科技计划课题(Z221100007522002)。
作者简介
第一作者:赵少伟,1998年生,硕士,工程师,主要从事水泥基材料及工业固废在混凝土中的应用相关研究工作,E-mail:19800300791@163.com;通信作者:王卉,1987年生,博士,高级工程师,主要从事水泥基胶凝材料、低碳混凝土、固废及二氧化碳建材资源化利用相关研究工作,E-mail:wanghui@bbma.com.cn。
