CFRP筋/钢筋与新型混凝土黏结性能试验研究

Experimental study on bond behavior between CFRP/steel bar and new type concrete

通过对27个中心拉拔试样进行测试,研究了碳纤维增强复合材料(CFRP)筋和钢筋分别与地聚物混凝土和硫铝酸盐混凝土两种新型混凝土之间的黏结性能、破坏模式和黏结-滑移关系曲线,并以普通混凝土为参照进行了对比分析。试验结果表明,对于同种混凝土,深螺纹CFRP筋与带肋钢筋的黏结-滑移曲线形状相似,均包含上升和下降段。深螺纹CFRP筋比带肋钢筋的黏结强度更高,且其最大黏结应力所对应的滑移量较带肋钢筋也更高。相比普通混凝土,硫铝酸盐混凝土与CFRP筋和钢筋的黏结性能较高,而地聚物混凝土因强度较低其黏结性能偏低。数据拟合结果显示,CMR模型比mBPE模型能够更好地拟合CFRP筋与地聚物混凝土、硫铝酸盐混凝土和普通混凝土之间的黏结-滑移试验曲线。

Through the of 27 central pull-out specimens,the bond properties,failure modes and bond-slip curves between carbon fiber reinforced polymer(CFRP)bars and steel bars and geopolymer concrete and sulphoaluminate concrete were studied respectively,and ordinary concrete was taken as the control group for comparative analysis.The test results show that,for the same kind of concrete,the bond-slip curves of deep-ribbed CFRP bars and ribbed steel bars are similar in shape,including ascending and descending sections.The bond strength of deep-ribbed CFRP bars is higher than that of ribbed steel bars,and the slip value corresponding to the maximum bond stress is also higher than that of ribbed steel bars.Compared with ordinary Portland concrete,sulphoaluminate concrete has higher bonding performance with CFRP bars and steel bars,while geopolymer concrete has lower bonding performance due to its lower strength.The data fitting results show that the CMR model can better fit the bond-slip test curves between CFRP bars and geopolymer concrete,sulphoaluminate concrete and ordinary Portland concrete than the mBPE model.