Kim Sun-Woo, Park Wan-Shin, Jang Young-Il, Jang Seok-Joon, Yun Hyun-Do
Department of Construction Engineering Education, Chungnam National University, Daejeon 34134, Korea.
Department of Architectural Engineering, Chungnam National University, Daejeon 34134, Korea.
Materials (Basel). 2017 Sep 14;10(9):1082. doi: 10.3390/ma10091082.
In order to assess the bond behavior of deformed steel rebars in recycled-aggregate concrete (RAC) incorporating both fine and coarse recycled aggregate, pull-out tests were carried out in this study on 16-mm diameter deformed steel rebars embedded concentrically in RAC. The concrete was designed using equivalently mixed proportions of both recycled coarse aggregate and recycled fine aggregate. The tests employed five types of recycled aggregate replacement combinations and three types of rebar placement orientation (i.e., vertical bars and two-tiered and three-tiered horizontal bars). Based on the pull-out test results, the maximum bond strength tended to decrease and the slip at the maximum bond strength increased as the average water absorption of the aggregate increased, irrespective of the rebar orientation or placement location within the concrete member. The pull-out test results for the horizontal steel rebars embedded in RAC indicate that the casting position effect could be determined from the mid-depth of the concrete member, irrespective of the member's height. The normalized bond versus slip relationship between the deformed rebar and the RAC could be predicted using an empirical model based on regression analysis of the experimental data.
为了评估同时包含细再生骨料和粗再生骨料的再生骨料混凝土（RAC）中变形钢筋的粘结性能，本研究对同心埋置于RAC中的直径16mm的变形钢筋进行了拉拔试验。混凝土采用再生粗骨料和再生细骨料等效混合比例进行设计。试验采用了五种类型的再生骨料替代组合以及三种类型的钢筋放置方向（即垂直钢筋以及两层和三层水平钢筋）。基于拉拔试验结果，无论钢筋在混凝土构件中的方向或放置位置如何，随着骨料平均吸水率的增加，最大粘结强度趋于降低，且在最大粘结强度时的滑移增加。埋置于RAC中的水平钢筋的拉拔试验结果表明，无论构件高度如何，均可从混凝土构件的中深度确定浇筑位置效应。基于试验数据的回归分析，可使用经验模型预测变形钢筋与RAC之间的归一化粘结与滑移关系。
