Reliability Analysis Of Reinforced Concrete Structures Strengthened With CFRP

Because of the increase of the input time of most buildings in our country,the corrosion of the building structure,the poor quality of construction and natural disasters,etc.,the bearing capacity and safety performance of the structure can not meet the predetermined requirements,so,these buildings must be repaired and reinforced.Carbon Fiber Reinforced Polymer(CFRP)has been widely used in the reinforcement of building structure with its excellent physical and mechanical properties.In order to analyze the safety of the reinforcement of the building structure,it is very important to study the variation law and influencing factors of the structural reliability index.The main contents and achievements are as follows:(1)This paper introduces several commonly used reliability calculation methods: the central point method,the design verification point method,the JC method and the mapping transformation method.The advantages and disadvantages and the application scope of each method are compared and analyzed.The JC method is mainly used in the later research analyze structural reliability indicators.(2)The influence of the load effect ratio and the amount of carbon fiber reinforced on the reliability index of the reinforced concrete beam subjected to bending and shear bearing capacity is analyzed.Five different load effect ratios are selected and calculated by JC method.The results show that the reliability index of the bending and shear bearing capacity decreases with the increase of the load effect ratio before and after reinforcement,and the decreasing trend is becoming more and more slow.Under the applicable conditions,Carbon fiber cloth,beam bending bearing capacity reliability index increased by about 4%,shear reliability index increased by 9%-14.6%.(3)The influence of the load-effect ratio,the corrosion rate of the steel bar and the amount of carbon fiber reinforcement on the bearing capacity of the column under axial compression were studied.The results show that the reliability index of the axial compression column decreases and decreases gradually with the increase of the load effect ratio before and after reinforcement.For each additional layer of carbon fiber cloth,The reliability index of the column increased by 3.7%-5.8%.(4)The reliability index of the large eccentric compression column should also consider the influence of the compression and bending reliability index.Use CFRP to reinforce the large eccentric compression column and then study the effect of load effect ratio and initial eccentricity on its reliability index.The results show that,the reliability index of the compression capacity,bending capacity,compression and bending capacity of the column decreases with the increase of the initial eccentricity and the load effect ratio,and the decreasing trend is gradually slowed down.The reliability index of the compression capacity is very little affected by the initial eccentricity before and after reinforcement.After the reinforcement of a layer of carbon fiber sheet,the reliability index of compression capacity is 4.7%-10.5%higher than that before reinforcement,11.2%-39.7% of bending capacity is improved,and the reliability index of the compression and bending capacity increased by 10.8%-39.5%,so choose the right amount of carbon fiber cloth to strengthen the column can be a good improvement of its bearing capacity and safety.