Mitigating alkali-silica reaction through metakaolin-based internal conditioning: New insights into property evolution and mitigation mechanism
Mitigating alkali-silica reaction through metakaolin-based internal conditioning: New insights into property evolution and mitigation mechanism
复制标题
DOI：
10.1016/j.cemconres.2022.106888
复制
发表时间：
2022-09
影响因子：
11.4
通讯作者：
Dayou Luo;A. Sinha;Madhab Adhikari;Jianqiang Wei
中科院分区：
文献类型：
--
作者：
Dayou Luo;A. Sinha;Madhab Adhikari;Jianqiang Wei
本研究通过监测含有活性骨料的砂浆的体积膨胀、开裂、渗透性、强度和微观结构，研究了偏高岭土基内部调节剂（MIC）在减轻碱-硅反应（ASR）中的作用。通过阐明不同组成的ASR凝胶的聚集体和性能评价的二氧化硅溶解，获得了对缓解机制的全面见解。ASR膨胀和开裂密度分别大幅降低至80.2%和73.5%，表明MIC在ASR抑制中的稳健作用优于偏高岭土或锂的单一使用。从共存的MIC和锂中观察到抑制ASR的多个先决条件的协同效应，这通过锂和铝之间在抑制二氧化硅溶解方面的互补效率、ASR凝胶的55.7%的低吸水率和87.3%的低溶胀势来解释，以及膨胀性ASR（Q3）凝胶向非膨胀性C-S-H（Q2）相的转化，使其成为设计耐久性混凝土的一种有前途的方法。
This study investigates the role of metakaolin-based internal conditioning (MIC) in mitigating alkali-silica reaction (ASR) by monitoring volume expansion, cracking, permeability, strength, and microstructure of mortar containing reactive aggregates. Comprehensive insights into the mitigation mechanisms were obtained by elucidating the silica dissolution of aggregate and property evaluations of ASR gels with varying compositions. Substantial decreases in ASR expansion and cracking density up to 80.2 % and 73.5 %, respectively, revealed the robust role of MIC in ASR suppression outperforming single uses of metakaolin or lithium. A synergistic effect in suppressing multiple prerequisites of ASR was observed from the co-existing MIC and lithium, which was explained by the complementary efficiency between lithium and aluminum in suppressing silica dissolution, 55.7 % lower water uptake and 87.3 % less swelling potential of ASR gel, as well as the conversion of expansive ASR (Q3) gel into non-expansive C-S-H (Q2) phase making it a promising approach in designing durable concrete.