Impact of temperature on expansive behavior of concrete with a highly reactive andesite due to the alkali-silica reaction
Impact of temperature on expansive behavior of concrete with a highly reactive andesite due to the alkali-silica reaction
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DOI：
10.1016/j.cemconres.2019.105888
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发表时间：
2019-11-01
影响因子：
11.4
通讯作者：
Scrivener, Karen
中科院分区：
文献类型：
--
作者：
Kawabata, Yuichiro;Dunant, Cyrille;Scrivener, Karen
采用碱包混凝土棱柱试验（AW-CPT），研究了温度对碱-硅反应（ASR）引起的混凝土膨胀性能和微观结构损伤的影响。早期膨胀高度依赖于温度，比后期膨胀更依赖于温度。在膨胀的早期阶段，ASR凝胶受到很好的抑制，因此早期膨胀速率主要取决于反应动力学。在后期阶段，由于ASR凝胶的粘度在较高温度下较低，因此它通过小裂缝或孔隙流出混凝土棱柱体，从而减少膏体开裂，并在较高温度下在包装布中检测到二氧化硅含量增加。因此，发现后期膨胀率在较高温度下降低。因此，大大加速的测试条件可能导致AW-CPT期间混凝土棱柱体的膨胀减少。
The influence of temperature on the expansive behavior and microstructural damage of concrete due to the alkali-silica reaction (ASR) is studied experimentally by applying a new testing protocol, the Alkali-Wrapped Concrete Prism Test (AW-CPT). Early-stage expansion is highly dependent on temperature, more so than expansion in later stages. In the early stages of expansion, the ASR gel is well restrained so that the early-stage expansion rate mainly depends on reaction kinetics. In later stages, since the viscosity of the ASR gel is lower at higher temperatures, it flows out of the concrete prism through small cracks or pores, resulting in reduced paste cracking and an increased silica content detected in the wrapping cloth at higher temperatures. Consequently, the late-stage expansion rate is found to be reduced at higher temperatures. Therefore, greatly accelerated test conditions may lead to reduced expansion of the concrete prism during the AW-CPT.