Effect of fire exposure on cracking, spalling and residual strength of fly ash geopolymer concrete
Effect of fire exposure on cracking, spalling and residual strength of fly ash geopolymer concrete
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DOI：
10.1016/j.matdes.2014.06.059
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发表时间：
2014-11-01
影响因子：
8.4
通讯作者：
Yao, Zhitong
中科院分区：
文献类型：
--
作者：
Sarker, Prabir Kumar;Kelly, Sean;Yao, Zhitong
粉煤灰基地质聚合物是一种新兴的替代水泥的粘结剂，用于制造混凝土。研究了地聚合物混凝土的开裂、剥落和剩余强度特性，以了解其耐火极限，这是其作为建筑材料的必要条件。将粉煤灰基地质聚合物和普通波特兰水泥（OPC）混凝土圆柱体样本暴露于高达1000摄氏度的不同温度下的火灾中，加热速率为国际标准化组织（ISO）834标准中给出的加热速率。混凝土的抗压强度在39-58 MPa的范围内变化。火灾暴露后，地质聚合物混凝土试样被发现遭受较少的损害，在开裂方面比OPC混凝土试样。OPC混凝土圆柱体在800和1000摄氏度的暴露条件下发生严重剥落，而地质聚合物混凝土样本中没有剥落。地质聚合物混凝土试样一般保持较高的强度比OPC混凝土试样。地质聚合物混凝土的扫描电子显微镜（SEM）图像显示，随着火灾温度的升高，微观结构的不断致密化。地聚合物混凝土试件的强度损失主要是由于地聚合物基体和骨料的热膨胀差异造成的。(C)2014爱思唯尔有限公司版权所有。
Fly ash based geopolymer is an emerging alternative binder to cement for making concrete. The cracking, spalling and residual strength behaviours of geopolymer concrete were studied in order to understand its fire endurance, which is essential for its use as a building material. Fly ash based geopolymer and ordinary portland cement (OPC) concrete cylinder specimens were exposed to fires at different temperatures up to 1000 degrees C, with a heating rate of that given in the International Standards Organization (ISO) 834 standard. Compressive strength of the concretes varied in the range of 39-58 MPa. After the fire exposures, the geopolymer concrete specimens were found to suffer less damage in terms of cracking than the OPC concrete specimens. The OPC concrete cylinders suffered severe spalling for 800 and 1000 degrees C exposures, while there was no spalling in the geopolymer concrete specimens. The geopolymer concrete specimens generally retained higher strength than the OPC concrete specimens. The Scanning Electron Microscope (SEM) images of geopolymer concrete showed continued densification of the microstructure with the increase of fire temperature. The strength loss in the geopolymer concrete specimens was mainly because of the difference between the thermal expansions of geopolymer matrix and the aggregates. (C) 2014 Elsevier Ltd. All rights reserved.