冻融循环作用下半套筒灌浆连接节点试验研究

Experimental Research on Semi Grouting Sleeve Splice under Freeze-Thaw Cycle

通过对Φ14 mm与Φ20 mm两种规格的半灌浆连接接头试件进行冻融循环及单向拉伸试验,对比常温及冻融循环作用下接头试件力学性能,分析冻融循环条件、冻融循环次数及钢筋直径对半套筒灌浆接头力学性能的影响。结果表明:与常温下试件相比,经冻融循环作用后试件的极限承载力较常温下试件出现一定程度下降,且随冻融循环次数增加下降幅度增大;经冻融循环作用后试件的破坏位移较常温下试件出现一定程度增加,且位移增加幅度随冻融循环次数增加而增大,破坏位移越大,表明钢筋与灌浆料之间的锚固性能越差;尽管试验用接头试件经冻融循环作用后力学性能出现一定程度下降,但其仍满足规范所需强度要求,可用于寒冷地区冻融循环条件下装配式建筑的施工。

Through freeze-thaw cycling and unidirectional tension tests on specimens of semi-grouted splices with two specifications of Φ14 mm and Φ20 mm,the mechanical properties of splice specimens under normal temperature and freeze-thaw cycling were compared,and the effects of freeze-thaw cycling conditions,freeze-thaw cycles and reinforcing bar diameter on the mechanical properties of semi-sleeve grouted splices were analyzed.The results show that,the ultimate bearing capacity of specimens under freeze-thaw cycles decreases to a certain extent compared with that under normal temperature,and increases with the increase of freeze-thaw cycles.The damage displacement of specimens under freezethaw cycles increases to a certain extent compared with that under normal temperature,and the increase range of displacement increases with the increase of freeze-thaw cycles.The larger the failure displacement is,the worse the anchorage performance between steel bar and grouting material is.Although the mechanical properties of test joint specimens decrease to a certain extent after freeze-thaw cycling,it still meets the strength requirements of specifications and can be used in the construction of assembly buildings under freeze-thaw cycling conditions in cold regions.