变形钢筋与活性粉末混凝土的粘结性能试验研究

通过不同直径和不同埋长的普通热轧变形钢筋活性粉末混凝土的钢筋拔出试验,研究变形钢筋与活性粉末混凝土的粘结性能及粘结—滑移的本构关系。研究表明:活性粉末混凝土与钢筋的极限粘结应力随着钢筋直径的增加而下降,钢筋直径相同时随着锚固长度的增加而降低。提出普通热轧变形钢筋与活性粉末混凝土的极限粘结强度与锚固长度的计算公式。运用该计算公式得出,直径为14和16 mm钢筋的锚固长度适宜取3倍钢筋直径,直径为18 mm钢筋的锚固长度适宜取4倍钢筋直径。根据试验数据回归出基于相对保护层厚度和相对有效粘结长度的极限粘结应力计算公式和粘结应力与滑移的本构关系式。

Experimental Research of Bond Capability between Deformed Bars and Reactive Powder Concrete

Based on a series of pulling tests of hot-rolled deformed bars with different diameter and embedding length from reactive powder concrete(RPC),the bond capability and the bonding-slipping constitutive relation between steel bars and RPC are studied in this paper.Results indicate that the ultimate bond stress between bars and RPC decreases with the increase of bar diameter or with anchorage length when bar diameter is the same.The formula is put forward for calculating the ultimate bond stress and the anchorage length of hot-rolled deformed bars and reactive powder concrete.By this formula,the adequate anchorage length for bars with the diameters of 14 and 16 mm is worked out to be 3 times of the bar diameters,and 4 times for bars with the diameter of 18 mm.According to experimental data,the ultimate bond stress and bonding-slipping constitutive relation are presented based on the thickness of protection layer and effective bond length.