冻融后钢筋再生混凝土粘结性能研究

为了进一步了解冻融环境下再生混凝土的抗拉性能及钢筋与再生混凝土的粘结性能,以100％再生粗骨科取代天然碎石制作了再生混凝土劈裂抗拉试件以及以钢筋直径12mm、16mm和20mm为变动因素的钢筋再生混凝土中心拔出试件.采用快冻法将劈裂抗拉试件和中心拔出试件进行冻融循环后分别进行劈裂和拉拔试验,研究冻融循环下再生混凝土劈裂抗拉性能及钢筋与再生混凝土间粘结性能的变化规律.在总结试验结果的基础上,提出了遭受冻融后再生混凝土劈裂抗拉强度及钢筋与再生混凝土间粘结强度的计算表达式,可为我国冻融环境下再生混凝土结构的耐久性设计提供有益的参考.

Study of Bond Performance between Steel Bar and Recycled Aggregate Concrete Subjected to Freeze-Thaw Cycling

In order to further understand the tensile performance of recycled concrete and the bond performance between steel bar and recycled aggregate concrete subjected to freeze-thaw cycling, splitting tensile samples of recycled concrete were prepared by using 100% recycled coarse aggregate instead of natural macadam, and pull-out samples of steel bar with diameter (d) of 12mm, 16mm, 20mm respectively and recycled aggregate concrete were prepared. Tensile test of splitting tensile specimen and pull-out test of pull-out specimen were carried out respectively based on fast freezing method freezing-thaw cycling. According to test results, the expression for evaluating the tensile properties of recycled concrete and the bond characteristics between steel bar and recycled aggregate concrete subjected to freezing-thaw cycling were proposed, which may provide a useful reference for durability design of structure composed of recycled aggregate concrete in freeze-thaw environment.