Effects of pozzolanic reaction on carbonation degree and strength of steel slag compacts containing zeolite
Effects of pozzolanic reaction on carbonation degree and strength of steel slag compacts containing zeolite
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DOI：
10.1016/j.conbuildmat.2021.122334
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发表时间：
2021-01-23
影响因子：
7.4
通讯作者：
Zhang, Yang yang
中科院分区：
文献类型：
--
作者：
Chang, Jun;Zhang, Xiong;Zhang, Yang yang
本文提出了沸石部分替代钢渣的新方法，以进一步提高钢渣在CO2固化后的压实物的性能（抗压强度和碳化程度）。电感耦合等离子体（ICP）结果表明，经水化养护1 d后，以沸石质量分数为5 wt%（水固比为10）取代的钢渣基体中Ca、Fe离子浓度分别比纯钢渣提高了78.19 mg/L和4.09 mg/L，分别提高了19.3%和99.0%。C(4)AF晶粒尺寸减小，Fe离子浓度增加，说明具有沸石性质的沸石可以与CaO-FeOx基体组分（C(4)AF）反应生成比CaO-FeOx基体具有更高溶解度的C- s - h凝胶，从而提高Ca离子浓度。从抗压强度和碳化程度的结果来看，沸石替代率分别为5 wt%和15 wt%。经1 d水化和2 h碳化养护后，掺5%沸石（CSZ5）的钢渣压实体抗压强度比纯钢渣压实体（CSZ0）高14%。在碳化程度方面，用沸石（CSZ15）代替的钢渣比用沸石（CSZ0）代替的钢渣碳化程度高10.2%。(C) 2021 Elsevier Ltd版权所有。
In this paper, a novel method, zeolite partially replacing steel slag, was proposed to futher improve the properties (compressive strength and carbonation degree) of steel slag compacts futher after CO2 curing. Inductively coupled plasma (ICP) results illustrated that the Ca, and, Fe ion concentrations in the steel slag matrix substituted by 5 wt% zeolite (water-to-solid ratio of 10) were 78.19 mg/L and 4.09 mg/L, 19.3% and 99.0% higher than that of pure steel slag after 1 d of hydration curing respectively. The decreased crystallite size of C(4)AF and increase in Fe ion concentration illustrates that zeolite with pozzolanic properties could react with CaO-FeOx matrix components such as brownmillerite (C(4)AF), to produce C-S-H gel, which possesses higher solubility than the CaO-FeOx matrix, to improve the Ca ion concentration. In terms of the compressive strength and carbonation degree results, the optimum zeolite substitution ratios were 5 wt% and 15 wt%, respectively. After 1 d hydration and 2 h of carbonation curing, the compressive strength of the steel slag compacts with 5 wt% zeolite (CSZ5) was 14% higher than that of pure steel slag compacts (CSZ0). With respect to carbonation degree, the steel slag substituted with 15 wt% zeolite (CSZ15) had a 10.2% higher carbonation level than that of CSZ0. (C) 2021 Elsevier Ltd. All rights reserved.