新型高强钢筋与混凝土粘结锚固性能试验

Experimental study of bond-anchorage properties of a new type high-strength rebar with concrete

通过对48个400 N/mm2级普通钢筋和630 N/mm2级高强钢筋与混凝土粘结锚固试件进行中心拔出试验,分别从试件破坏形态、粘结锚固强度、粘结滑移性能等方面进行对比分析,在统计回归的基础上给出了630 N/mm2级高强钢筋粘结强度的计算公式,提出锚固长度的设计建议。研究表明:普通钢筋与高强钢筋试件的破坏形态类似,粘结-滑移曲线变化规律相近;在相同条件下,高强钢筋粘结强度高于普通钢筋;与普通钢筋类似,高强钢筋与混凝土的粘结强度随混凝土强度的提高、锚固长度和钢筋直径的减小而增大;混凝土强度和钢筋锚固长度变化对高强钢筋的粘结强度影响比普通钢筋更为显著;《混凝土结构设计规范》(GB50010-2010)锚固长度计算公式适用于630 N/mm2高强钢筋.

In order to investigate the failure mode,bond-anchorage strength and bond-slip properties of specimens,48 specimens of 400 N/mm2 ordinary steel rebars and 630 N/mm2 high strength steel rebars bonded with concrete were studied by central pull-out test.On the basis of statistical regression,the formula for calculating the bond strength of 630 N/mm2 high strength steel rebars is given,and the design proposal of anchorage length is put forward.The results show that the failure modes of common steel rebar and highstrength steel rebar are similar.The bond-slip curves are similar.Under the same conditions,the bond strength of high-strength steel rebar is higher than that of common steel rebar.Similar to ordinary steel rebars,the bond strength between high-strength steel rebars and concrete increases with the increase of concrete strength,the decreases of anchorage length and the diameter of steel rebars.Compared with ordinary steel rebar,the change of concrete strength or anchorage length of steel rebar has more significant effect on the bond strength of highstrength steel rebar.The formula for calculating anchorage length in Code for Design of Concrete Structures(GB50010-2010)is applicable to 630 N/mm2 high strength steel rebars.