BFRP筋与地聚物混凝土黏结性能试验研究

通过对51个玄武岩纤维复合材料（BFRP）筋-地聚物混凝土界面黏结试件进行中心拉拔试验，分析了BFRP筋与地聚物混凝土的界面黏结破坏机理，研究了BFRP筋表面形式（浅螺纹、喷砂和深螺纹）、直径d（12、16 mm和20 mm）、黏结长度（2.5d、5d和7.5d）、地聚物混凝土强度等级（C30、C40和C50）及混凝土保护层厚度（20、45 mm和69 mm）等因素对BFRP筋-地聚物混凝土界面性能的影响，并与9个BFRP筋-普通混凝土界面黏结试件中心拉拔试验结果进行比较。试验结果表明：BFRP筋-地聚物混凝土界面黏结强度与BFRP筋-普通混凝土界面黏结强度基本相同；BFRP筋表面形式对其黏结性能影响较大，直径为12 mm时，浅螺纹、喷砂和深螺纹BFRP筋与地聚物混凝土的黏结强度分别为15.33、20.49 MPa和22.66 MPa；随着FRP筋直径和黏结长度的增加，BFRP筋与地聚物混凝土黏结强度降低，而随着混凝土强度和和保护层厚度的增加，黏结强度提高。通过CMR和mBPE模型对试验所得黏结应力-滑移曲线进行拟合，发现CMR模型能够较为准确的描述BFRP筋与地聚物混凝土间的黏结应力-滑移关系。

Experimental investigation on bond behavior of basalt fiber reinforced polymer bars to geopolymer concrete

Pull-out tests were carried out on 51 basalt fiber reinforced polymer (BFRP) bar-geopolymer concrete bond specimens to analyze the bond failure mechanism. The influence of BFRP bar surface treatment (shallow ribbed, sand coated, and deep ribbed), BFRP diameter (12 mm, 16 mm, and 20 mm), the bond length of BFRP bars (2.5d, 5d, and 7.5d), geopolymer concrete strength grade (C30, C40, and C50) and cover thickness of geopolymer concrete (20 mm, 45 mm and 69 mm) on the interfacial bond performance between BFRP bars and geopolymer concrete were investigated, and the bond behaviors were compared with those between BFRP bars and ordinary concrete. The results show that the interfacial bond strengths between BFRP bars and geopolymer concrete are similar to those between BFRP bars and ordinary concrete. The surface treatment form of the BFRP bar has a great influence on its bond performance. The bond strength of shallow ribbed, sand coated, deep ribbed BFRP bars with a diameter of 12 mm to geopolymer concrete are 15.33 MPa, 20.49 MPa, and 22.66 MPa respectively. Meanwhile, the bond strength between BFRP reinforcement and geopolymer concrete decreases with the increase of FRP bar diameter and bond length, while increasing with the increase of concrete strength and cover thickness. Finally, the CMR and mBPE models were adopted to fit the tested bond-slip τ-s curves. The results show that the CMR model can accurately describe the bond-slip relationship between BFRP bars and geopolymer concrete.