Abstract: The shapes, attached mortar and the microhardness of interface transition zone of recycled coarse aggregate prepared by three different processes were analyzed. And the effects of aggregate shapes and defects on drying shrinkage and mechanical properties were studied. Combining with the drainage characteristics, microhardness and failure patterns of aggregate, the difference of defects caused by different processes on recycled aggregate and its influence mechanism on drying shrinkage and mechanical properties of recycled concrete were discussed. The results show that comparing with jaw crusher, the aggregate prepared by impact crusher has better shape, less needle shape, and the content of attached mortar is obviously reduced. And the disc reshaping technology can further improve the aggregate shape and reduce the content of attached mortar on the aggregate surface. The mortar contained in recycled aggregate leads to high water absorption, which has a certain internal curing effect and reduce its early shrinkage, but the evaporation of water in the later period would lead to the increase of dry shrinkage of recycled concrete. The interfacial microhardness of recycled aggregate RA-C1 prepared by impact crusher is higher than that of RA-E prepared by Jaw crusher, and the strength of concrete prepared by impact crusher is higher than that of RA-E, while RA-C2 prepared by impact crusher and reshaping has the best interfacial properties, its mechanical properties are relatively low due to the low strength of aggregate.
孙道胜, 李泽英, 刘开伟, 王爱国, 黄伟, 张高展. 再生粗骨料的形态及缺陷对再生混凝土干燥收缩和力学性能的影响[J]. 材料导报, 2021, 35(11): 11027-11033.
SUN Daosheng, LI Zeying, LIU Kaiwei, WANG Aiguo, HUANG Wei, ZHANG Gaozhan. Influence of Shapes and Defects in Recycled Aggregate on Drying Shrinkage and Mechanical Properties of Recycled Aggregate Concrete. Materials Reports, 2021, 35(11): 11027-11033.
Esin T, Cosgun N. Building and Environment,2007,42(4),1667.
2
Oikonomou N D. Cement and Concrete Composites,2005,27(2),315.
3
Roussat N, Dujet C, Méhu J. Waste Management,2009,29(1),12.
4
Rajput S P, Chouhan M S. Civil and Environmental Research,2013,3(9),36.
5
Bribián I Z, Capilla A V, Usón A A. Building & Environment,2011,46(5),1133.
6
Etxeberria M, Vázquez E, Marí A, et al. Cement and Concrete Research,2007,37(5),735.
7
Padmini A K, Ramamurthy K, Mathews M S. Construction and Building Materials,2009,23(2),829.
8
Gao D Y, Zhang L J, Lu J Y, et al. Journal of Architecture and Civil Engineering,2016,33(1),8(in Chinese).
高丹盈,张丽娟,芦静云,等.建筑科学与工程学报,2016,33(1),8.
9
Guo Y X, Li Q Y, Yue G B, et al. Journal of Building Structures,2018,39(4),153(in Chinese).
郭远新,李秋义,岳公冰,等.建筑结构学报,2018,39(4),153.
10
Shi C J, Cao Z J, Xie Z B. Materials Reports A:Review Papers,2016,30(12),96(in Chinese).
史才军,曹芷杰,谢昭彬.材料导报:综述篇,2016,30(12),96.
11
Li W G, Long C, Luo Z Y, et al. Journal of Building Materials,2017,20(5),685(in Chinese).
李文贵,龙初,罗智予,等.建筑材料学报,2017,20(5),685.
12
Ouyang K, Shi C, Chu H, et al. Journal of Cleaner Production,2020,263,121264.
13
Xu P Z, Chen F B, LI Q Q, et al. Materials Reports B:Research Papers,2020,34(3),6095(in Chinese).
徐培蓁,陈发滨,李泉荃,等.材料导报:研究篇,2020,34(3),6095.
14
Barbudo A, Agrela F, Ayuso J, et al. Construction and Building Mate?rials,2012,28(1),129.
15
Quan H Z, Ding J D, Zhu Y G, et al. In: Proceedings of the 1st Symposium on Research and Applicaton of Recycled Concrete in PR China. Beijing,2008,283(in Chinese).
全洪珠,丁杰东,朱亚光,等.首届全国再生混凝土研究与应用学术交流会.北京,2008,283.
16
Yue G B, Ma Z M, Liu M, et al. Construction and Building Materials,2020,245,118419.
17
Amorim P, Brito J D, Evangelists L. ACI Materials Journal,2012,109(2),195.
18
Cui Z L, Zhang H. Advanced Engineering Sciences,2020,52(6),143(in Chinese).
崔正龙,张含.工程科学与技术,2020,52(6),143.
19
Liu Q, Xiao J Z, Pan Z S, et al. Journal of Building Materials,2020,41(12),133(in Chinese).