【作者】 梁金福；

【导师】 燕柳斌；

【作者基本信息】 广西大学 ， 结构工程， 2014， 博士

【摘要】 CFRP板嵌入式加固法是一种新形式的加固方法。CFRP板嵌入式加固法是指预先在需要加固的构件表面开槽,其次向槽中注入粘结材料,然后将CFRP板放入槽中来改善构件受力性能的加固方法。与表面外贴法相比,CFRP板嵌入式加固法具有材料用量少、耐腐蚀、适用于表面不平的构件,与构件传力更有效,遭受意外荷载不易损伤等特点。本文制作了17根钢筋根混凝土梁,试验梁设计时考虑了配筋率、CFRP板加固量和钢筋混凝土梁损伤等3种试验参数。通过测定试验梁的开裂荷载、屈服荷载、极限荷载、变形、裂缝以及试验梁混凝土、钢筋、碳纤维应变,分析CFRP板条嵌入式加固钢筋混凝土梁的破坏机理,研究配筋率、CFRP板加固量和损伤情况等对加固梁裂缝发展、开裂荷载、屈服荷载、极限荷载及刚度的影响,并对比CFRP板条嵌入式加固损伤钢筋混凝土梁与外贴CFRP板条加固损伤钢筋混凝土梁的加固效果。在试验研究的基础上,对加固梁的受弯承载力、挠度计算方法和裂缝计算方法进行理论研究。主要研究工作如下：1、进行CFRP板条嵌入式加固钢筋混凝土梁的抗弯试验研究,分析CFRP板条嵌入式加固钢筋混凝土梁的破坏机理,研究配筋率、CFRP板加固量和梁损伤情况等对加固破坏形式、裂缝发展、开裂荷载、屈服荷载、极限荷载及刚度的影响。2、在现有CFRP加固结构构件的承载力计算模型的基础上,根据钢筋混凝土梁抗弯承载力计算的基本理论,探讨CFRP板条嵌入式加固钢筋混凝土梁承载力计算方法。3、采用最小刚度原则,分析CFRP板条嵌入式加固钢筋混凝土梁在正常使用状态下的刚度,推导加固梁跨中挠度计算公式。4、根据钢筋混凝土梁裂缝计算理论,推导加固梁在正常使用状态的平均裂缝间距和最大裂缝宽度计算公式。通过上述的试验研究和理论研究,得出如下一些结论：1、加固梁的破坏形式主要受配筋率和加固量的影响；采用CFRP板条嵌入式加固可以有效的提高加固梁的特征荷载；加固梁的变形性能主要受加固量和初始荷载影响。2、在不考虑发生CFRP板剥离破坏的情况下,推导建立加固梁的承载力计算公式,计算结果与试验值基本吻合。3、推导出的挠度计算公式计算正常使用状态下加固梁的跨中挠度,计算值与试验值较吻合。4、根据钢筋混凝土梁裂缝计算理论,给出了正常使用状态下加固梁的平均裂缝间距和最大裂缝宽度计算公式。通过和试验值比较,计算值与试验值相差较小。更多还原

【Abstract】 Near-surface mounted CFRP is a new reinforcement method. Near-surface mounted CFRP is a reinforcement method to advance on the surface of the components that need to reinforce the slot, and then put the CFRP strips into slots to improve the mechanical performance of the component. Compared with the surface stick method, near-surface mounted CFRP has the advantages of low dosage of materials, corrosion resistance, applicable to the uneven surface of the component, and more effective component force, suffers accident load is not easy to damage, etc.This paper designs17RC beams, the beams when considering the reinforcement ratio, amount of CFRP and damage as test parameters. By measuring test of cracking load, yield load, ultimate load, deformation, cracks and strain of concrete, steel bar, CFRP strip. Analysis the failure mechanism of RC beams, the influence of the cracking load, yield load, ultimate load and stiffness is researched by reinforcement ratio, amount of CFRP and damage, and then analysis the strengthening effect between the external bonded and Near-surface mounted. On the basis of experimental study, the ultimate capacity, cracks calculation method and deflection calculation method for theoretical research. The main research work is as follows:1. Study on flexural performance of Damaged RC beams strengthed with Near-Surface Mounted CFRP strips, analysis the failure mechanism of RC beams, the influence of the cracking load, yield load, ultimate load, stiffness is researched by reinforcement ratio, amount of CFRP and damage.2. In the existing model for calculating the ultimate bearing capacity of CFRP reinforced structures, on the basis of calculated according to the basic theory of reinforced concrete beam bending bearing capacity and discusses calculation method of bearing capacity of reinforced concrete beam.3. Using the principle of minimum stiffness, analysis of the stiffness RC beams with NSM under normal use, and midspan deflection calculation formula is derived. 4. According to theory of crack of RC beam, calculation formulate for average cracks distance and maximum crack width are derived.Through the experimental study and theoretical study, draw some conclusions as follows:1. Failure modes of RC beams with NSM were mainly affected by the amount of CFRP and reinforcement ratio; NSM can effectively improve the characteristic load; Deformation of the RC beam with NSM was mainly affected by amount of CFRP and initial load.2. Without considering the CFRP stripping failure situation, establish a formula of the bearing capacity is derived, the calculation results with the theoretical results fit well.3. Calculate the midspan deflection with the calculating formula of the deflection with is derived under the normal use, the calculated value and the experimental results fit well with.4. According to the theory of RC beam crack calculation shows the normal use of the reinforced beam under the average crack spacing and maximum crack width calculation formula. By comparing the test data and calculated values and experimental values are smaller.更多还原