On drying shrinkage in alkali-activated concrete: Improving dimensional stability by aging or heat-curing
On drying shrinkage in alkali-activated concrete: Improving dimensional stability by aging or heat-curing
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DOI：
10.1016/j.cemconres.2016.10.003
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发表时间：
2017-01-01
影响因子：
11.4
通讯作者：
Peethamparan, Sulapha
中科院分区：
文献类型：
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作者：
Thomas, R. J.;Lezama, Diego;Peethamparan, Sulapha
碱活性混凝土（AAC）的过度干燥收缩问题在文献中有很好的记载。干燥收缩的幅度通常是波特兰水泥混凝土的三倍或更多倍。本研究探讨胶凝材料种类、激发剂浓度、强度、龄期及养护方式对碱激发粉煤灰及矿渣水泥混凝土干缩表现之影响。在AAC中观察到超过1200 μ m（0.12%应变）的早期收缩应变。这归因于延迟水化、微观结构细化和强度发展。由此造成的损害远比波特兰水泥混凝土严重。收缩和由此产生的损害大大减少时，试样干燥后，在较晚的年龄和热固化。碱矿渣水泥混凝土比波特兰水泥和碱激发粉煤灰混凝土对水的损失更敏感。这是由于碱活化矿渣粘结剂中的细孔结构。(C)2016爱思唯尔有限公司版权所有。
The problem of excessive drying shrinkage in alkali-activated concrete (AAC) is well-documented in the literature. The magnitude of drying shrinkage is often three or more times that in portland cement concrete. This study investigates the effects of binder type, activator concentration, strength, age, and curing method on the manifestation of drying shrinkage in alkali-activated fly ash and slag cement concrete. Early-age shrinkage strains in excess of 1200 mu epsilon (0.12 percent strain) are observed in AAC. This is attributed to delayed hydration, microstructure refinement, and strength development. The resulting damage is far more significant than in portland cement concrete. Shrinkage and resulting damage are greatly reduced when specimens are dried at later age and after heat-curing. Alkali-activated slag cement concrete is more sensitive to water loss than portland cement or alkali-activated fly ash concrete. This results from a finer pore structure in alkali-activated slag binders. (C) 2016 Elsevier Ltd. All rights reserved.