HRBF500钢筋与混凝土粘结试验研究

首先通过HtCBF500级细晶高强钢筋的材性试验，表明HtKBF500钢筋均有明显的屈服台阶，其实测屈服强度都达到了500MPa级的要求，强屈比σb／σs=1．23～1．32，伸长率δ5均在20％以上，强度和延性均较好，弹性模量E5=2．0×10^5-2．1×10^5，与普通热轧钢筋基本相同；然后通过对42个HRBF500钢筋与混凝土粘结试件的拔出试验，观察其破坏现象可分为三种典型破坏：即混凝土劈裂、钢筋拔出、混凝土先压碎后钢筋拔出，描述了试验荷载-滑移（F—s）曲线和平均粘结应力-滑移（^-τ-s）曲线，并根据曲线的特征，研究了锚筋受力破坏各个阶段的特点。

Experimental Study on Bond Properties of HRBF500 Steel Bars in Concrete

Firstly, material property test on HRBF500 steel bar was made, it is demonstrated that obvious yield level existed in the HRBF500 steel bars,and the measured yield strength met 500MPa grade requirements , strength-yield ratio σb / σs, =1.23 -1.32, elongation δ5 are all above 20% ,strength and ductility are both very well, modulus of elasticity E5=2.0 × 10^5- 2.1 × 10^5MPa,which are similar with the normal hot-rolled steel bars. Afterwards, 42 HRBF500 steel bar specimens pull-out tests were made, it is observed that the failure phenomenon can be classified to three typical cases： concrete separation, rebar pulled out, concrete crashing then rebar pulled out. Besides, test force- slippage curve and average bond strees- slippage curve are described, and then the characteristics of anchorage rebar failure at various stages are studied accoring to the curve features.