HPFL加固受火RC梁刚度及挠度研究

结合国内外对火灾后钢筋混凝土结构中混凝土和钢筋力学性能的研究，分别采用三台阶模型和二台阶模型对火灾后混凝土和钢筋的弹性模量进行简化计算.根据简化计算模型和等效弹性模量法，对受火后钢筋混凝土梁截面的弹性模量进行等效，得到受火后钢筋混凝土梁截面的弹性模量.根据有效惯性矩法，对高性能复合砂浆钢筋网加固受火RC梁开裂前和开裂后的截面进行等效换算，将受拉区钢筋和全截面的高性能复合砂浆钢筋网换算成弹性模量为混凝土弹性模量的换算截面.在考虑剪切变形影响的前提下，对高性能复合砂浆钢筋网加固受火RC梁的截面刚度和挠度进行理论推导，并结合实验数据验证理论公式的合理性.分析结果表明，推导所得的计算公式与试验数据基本吻合.
Combined with domestic and international research on the mechanical properties of concrete and steel after fire, a three-step model and a two-step model were used to calculate the elastic modulus of concrete and steel simply, respectively. According to the simplified calculation model and the equivalent elastic modulus method, an equivalent cross-section elastic modulus of reinforced concrete beams was obtained after fire. Based on the effective moment of inertia method, the cross section of the reinforced concrete beam was equivalently translated before and after the reinforced concrete beam cracked. Area of the whole cross-section mortar and the reinforced area of tension zone were translated to the effective area whose modulus of elasticity is the concrete modulus of elasticity. Through the experiment data, design formula of the stiffness and deflection of the reinforced concrete beam with high-performance ferrocement laminate after fire was deduced and verified. The calculation results are in good agreement with the experimental ones.