摘要
在CO_(2)浓度为99%,压力为0.2 MPa条件下,对钢渣复合胶凝材料进行碳酸化-水化耦合养护,调节碳酸化-水化耦合机制和碳酸化时间,分析硬化浆体的抗压强度、固碳量、矿物组成、微观形貌以及Cr离子溶出规律。结果表明钢渣/水泥试块标准养护3 d后进行碳酸化养护,3 d和28 d强度均达到最高。水化养护3d后进行碳酸化养护1 h、2 h、6 h,可使3 d的抗压强度提升16.3%、26.5%、50.2%,后期水化强度持续增长,28 d强度分别提高17.6%、27.7%、22.8%且安定性良好。水化养护28 d后进行碳酸化的试块固碳量最高,这是因为水化养护3 d后进行碳化,参与碳化反应的主要是C2S、C3S等,水化养护28 d后进行碳化,参与碳酸化反应的主要是C-S-H凝胶、Ca(OH)2,及未反应的C2S、C3S等。C-S-H凝胶和Ca(OH)2碳化活性较高,固碳能力强,但碳化产物强度较低。不同的碳酸化-水化耦合机制对Cr离子的固化作用也有显著的影响,水化养护3 d后进行碳酸化处理的固化效果最好,碳酸化养护6 h的试块,Cr离子溶出降低58.2%。
It aimed to investigate the effect of carbonation-hydration coupling curing mechanism on the CO_(2)uptake,compressive strength,volume stability and Cr leaching of cement paste containing high content of stainless steel slag.Cement paste was exposed to CO_(2)(99.9%,0.2 MPa)for carbonation curing after hydration for 3 d,7 d and 28 d.The results indicated that carbonation-hydration procedure has a significant impact on the compressive strength of hardened paste.Hardened pasted carbonation curing for 1 h,2 h,and 6 h after hydration curing for 3 d can increase the compressive strength by 16.3%,26.5%,and 50.2%,and the hydration reaction will continue and impart the paste a continuously increasing compressive strength.The compressive strength of 28 d increased by 17.6%,27.7%,22.8%.The CO_(2)uptake and Cr leaching of the paste also depends on carbonation-hydration coupling curing mechanism.C2S,C3S and the hydration products(C-S-H gel and Ca(OH)2)can react with CO_(2)to form stable calcium carbonate.C-S-H gel and Ca(OH)2 show better carbonation activity than that of C2S,C3S,thereby samples exposed to CO_(2)after 28 d hydration curing absorb most CO_(2).Carbonation-hydration curing show excellent solidification effect on Cr from stainless steel slag,and the Cr leaching of samples carbonated for 6 h after hydration for 3 d decreased by 58.2%compared to the reference samples.
作者
房延凤
姚淑红
王庆贺
尚小朋
丁向群
佟钰
FANG Yanfeng;YAO Shuhong;WANG Qinghe;SHANG Xiaopeng;DING Xiangqun;TONG Yu(School of Materials Science and Engineering,Shenyang Jianzhu University,Shenyang 110168,China;School of Civil Engineering,Shenyang Jianzhu University,Shenyang 110168,China;Department of Architectural Engineering,Shandong Urban Construction Vocational College,Jinan 250103,China)
出处
《混凝土》
CAS
北大核心
2024年第2期137-141,共5页
Concrete
基金
国家自然科学基金(52378252)
辽宁省教育厅科学研究经费项目(lnjc202017)。
关键词
不锈钢渣
碳酸化
力学性能
碳化产物
CR
stainless steel slag
carbonation
mechanical property
carbonation products
Cr
