高温后CFRP筋及其粘结式锚固系统的力学性能

为明确高温后碳纤维增强树脂复合材料(Carbon fiber reinforced polymer，CFRP)筋材及其粘结型锚固系统的力学性能，以筋材的处理温度为试验参数，完成了12个筋材试件的轴向拉伸试验；以粘结式锚具的处理温度和粘结长度为试验参数，完成了36个试件的锚固性能试验。结果表明:对于筋材轴向拉伸试件，处理温度为100℃时，筋材静力性能与常温试件相比未发生明显变化，筋材经历200℃和300℃温升作用后，其抗拉强度、弹性模量和极限拉应变较常温试件分别下降了6.4%、8.2%、3.8%和16.6%、18.3%、8.3%；对于锚固性能试验，试件的粘结强度随处理温度和粘结长度的增加而降低，粘结长度一定时，处理温度为200℃与300℃试件的粘结强度较常温试件分别下降了31.5%~36.3%和44.2%~47.4%。建立了适于分析高温后CFRP筋轴向拉伸性能、粘结型锚固系统粘结强度及临界锚固长度的实用计算公式，且具较高精度。 

Mechanical properties of CFRP bar and bond-type anchorage system after elevated temperature exposure

To investigate the mechanical properties of carbon fiber reinforced polymer (CFRP) bar and bond-type anchorage system after different elevated temperature exposures, the axial tensile tests and anchorage perfor-mance tests were conducted on 12 specimens and 36 specimens with different elevated temperatures and bond lengths, respectively. The results demonstrate that the static performance of CFRP bar exposed to elevated temperature of 100℃ degenerates slightly compared with the specimen at room temperature in the axial tensile tests. The tensile strength, elastic modulus and ultimate strain of specimens exposed to the elevated temperature of 200℃ and 300℃ decrease by 6.4%, 8.2%, 3.8% and 16.6%, 18.3%, 8.3%, respectively, compared with the specimen at room temperature. In the anchorage performance tests, the bond strength of the specimens decreases with the increase of elevated temperature and bond length. Compared with the specimen at room temperature, the bond strengths of the specimens exposed to the elevated temperature of 200℃ and 300℃ decrease by 31.5%-36.3% and 44.2%-47.4%, respectively, while the bonding length is fixed. The practical formulas with high accuracy for determining the axial tensile performance of CFRP bars, bond strength and critical anchorage length of the bond-type anchorage system after elevated temperature exposure were developed.