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在ISO834标准升温条件下,开展了具有端部约束的7根碳纤维布加固混凝土梁和1根未加固混凝土梁的耐火性能试验,考察了梁端轴向和转动约束、防火涂料厚度、荷载比等参数对约束梁高温变形及内力的影响。试验结果表明:约束梁的轴向变形最大值随轴向约束刚度比和防火涂料厚度增大而减小,附加轴力最大值随轴向约束刚度比增加或防火涂料厚度减小而增大,梁端附加弯矩最大值随防火涂料厚度减小而增大,但防火涂料厚度在10~20mm范围内变化时影响幅度有限;降温后约束梁的附加轴力仅少量恢复,梁端附加弯矩却较大幅度回落;与非加固梁相比,加固梁的梁端附加弯矩最大值不仅数值更小,而且出现时刻明显偏晚。
Under the condition of ISO834 standard temperature, the fire resistance test of seven CFRP-reinforced concrete beams and one unconfined concrete beam with end restraint was carried out. The axial and rotational restraint of the beam ends, the thickness of fireproof coating, the load ratio and so on Influence of Parameters on High Temperature Deformation and Internal Force of Constrained Beam. The experimental results show that the maximum axial deformation of the restraint beam decreases with the axial restraint stiffness ratio and the thickness of the fire retardant coating, and the maximum value of the additional axial force increases with the axial restraint stiffness ratio or the thickness of the fire retardant coating decreases. The maximum additional bending moment of beam increases with the decrease of the thickness of the fire retardant coating, but the influence range is limited when the thickness of the fire retardant coating changes within the range of 10 ~ 20mm. After the cooling, the additional axial force of the restraining beam restores only a little, Compared with the non-reinforced beam, the maximum value of the additional bending moment at the beam end of the reinforced beam is not only smaller, but also appears significantly later.