Sulfate and acid resistance of lithomarge-based geopolymer mortars
Sulfate and acid resistance of lithomarge-based geopolymer mortars
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DOI：
10.1016/j.conbuildmat.2018.01.129
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发表时间：
2018-03-30
影响因子：
7.4
通讯作者：
Cleland, David J.
中科院分区：
文献类型：
--
作者：
Kwasny, Jacek;Aiken, Timothy A.;Cleland, David J.
评价了室温固化的地质聚合物砂浆（GPM）对化学侵蚀（即硫酸钠和硫酸镁溶液以及硫酸和盐酸溶液）的耐受性。使用岩藻前体（低纯度高岭土）配制GPMs，以实现37.5和60 MPa的28天特征抗压强度。它们的性能进行了比较，相当于波特兰水泥砂浆（PCM）具有相同的膏体体积和强度等级。当与PCM相比时，具有两个强度等级的GPMs显示出抗硫酸盐侵蚀的上级性能。与严重劣化的PCM相比，在GPMs中未观察到视觉劣化，质量和长度变化相对较小，并且未检测到微观结构的变化。正如通过目视观察和较低的质量损失所证实的，GPMs比PCM对两种酸的侵蚀表现出更好的抗性。GPS提供了一个更好的质量（较低的渗透性）的酸降解层，降低了进一步恶化的程度。在这两种酸中的基体变质的GPMs的主要机制是脱铝的硬化粘结剂，与硫酸检测到的变化程度较高。(C)2018爱思唯尔有限公司版权所有。
The resistance of room temperature cured geopolymer mortars (GPM) against chemical attacks, i.e. sodium and magnesium sulfate solutions, and sulfuric and hydrochloric acid solutions, was evaluated. GPMs were formulated using a lithomarge precursor (low-purity kaolin) to achieve 28-day characteristic compressive strengths of 37.5 and 60 MPa. Their performance was compared with those of equivalent Portland cement mortars (PCMs) having the same paste volume and strength grade. GPMs with both strength grades showed superior performance against sulfate attack when compared to PCMs. No visual deterioration was observed in GPMs, the mass and length changes were relatively small, and no changes to the microstructure were detected - in contrast to severely deteriorated PCMs. As confirmed by visual observations and lower mass loss, GPMs showed better resistance to attack by both acids than PCMs. GPMs provided a better quality (lower permeability) of an acid-degraded layer, lowering the degree of further deterioration. The main mechanisms of the matrix deterioration of GPMs in both acids was dealumination of the hardened binder, with a higher degree of changes detected for sulfuric acid. (C) 2018 Elsevier Ltd. All rights reserved.