Tensile creep behavior of Alkali-activated slag concrete incorporating lightweight aggregate
Tensile creep behavior of Alkali-activated slag concrete incorporating lightweight aggregate
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DOI：
10.1016/j.conbuildmat.2022.129318
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发表时间：
2022-11
影响因子：
7.4
通讯作者：
Xiaoyan Zheng;Hongye Lu;Shengjie You;Kejia Cheng;S. Easa;Zongyan Chen;Chun Ma;Dabao Fu;Tao Ji
中科院分区：
文献类型：
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作者：
Xiaoyan Zheng;Hongye Lu;Shengjie You;Kejia Cheng;S. Easa;Zongyan Chen;Chun Ma;Dabao Fu;Tao Ji
研究了预湿轻集料对碱矿渣混凝土（AASC）14 d拉伸徐变的影响。试验采用0、50%和100%三种不同的轻集料取代率，并以掺有轻集料的普通波特兰水泥混凝土（OPCC）为对照。结果表明，在相同的LWA含量下，AASCs的拉伸蠕变大于OPCCs的拉伸蠕变。预湿LWA的掺入显著降低了AASCs的自收缩和拉伸蠕变，且随着LWA含量的增加，自收缩和拉伸蠕变的降低幅度不断减小。1d的早期龄期占AASCs 14 d拉伸蠕变总量的70%以上。此外，预湿LWA对降低AASC体系的拉伸蠕变比OPCC体系有更大的影响。同时，预湿LWA的加入降低了AASCs的徐变/收缩比。此外，预湿轻骨料的加入对碱矿渣水泥的开裂龄期有一定的延缓作用，且随着预湿轻骨料含量的增加，这种延缓作用更加明显。
This study aims to investigate the effect of pre-wetting lightweight aggregate (LWA) on the tensile creep of alkali-activated slag concrete (AASC) for 14 d. Three replacement rates of natural coarse aggregate with LWA were used in this study, including 0, 50%, and 100%, and the Ordinary Portland cement concretes (OPCCs) mixed with LWAs were considered as control samples. The results showed that the tensile creep of the AASCs was higher than those of OPCCs with the same LWA content. The incorporation of pre-wetting LWA significantly reduced the modified autogenous shrinkage and tensile creep of the AASCs, and the magnitudes were continuously declined with the increase in LWA contents. The early age of 1 d dominated more than 70% of the total tensile creep of the AASCs for 14 d. Furthermore, pre-wetting LWAs had a greater effect on decreasing tensile creep for the AASC system than the OPCC system. Meanwhile, the creep/shrinkage ratio of the AASCs was declined by the addition of pre-wetting LWAs. In addition, the cracking age of the AASC was desirably delayed by adding pre-wetting LWA, and the effect was more noticeable with the increase in LWA contents.