The Research On The Flexural Behavior Of RC Continuous Beams Strengthened By BFRP Under The Secondary Loads

The concrete buildings suffer from the erosion of natural environment and social environment for a long time,its performance will reduce gradually,this is also the role of the law of nature.Based on this,it has become a hot issue in the field of structure strengthening that how to delay the structure's process of the damage scientifically and prolong it.As a new type of reinforcement material,Basalt Fiber Reinforced Polymer will be a popular fiber material following the GFRP and CFRP because of its high strength,high modulus,high temperature resistance and chemical stability.The secondary load itself is not allowed to ignore.Now there are few of study on the flexural behavior of performance of RC continuous beams strengthened by BFRP considering the secondary loads at home and abroad,even considering the influence of the secondary loads,the projects of research are more focused on the reinforcement of RC beams.Through the study of 11 continuous beams,in this passage,based on the theory analysis of elastic-plastic mechanics and the nonlinear analysis of concrete,the influence of the complete flexural calculation process of reinforced concrete continuous beams strengthened by BFRP was researched by studying the condition forming by different initial loads and different layers of the BFRP sheet,the accuracy is verified by connecting with the ABAQUS finite element software simulation.The main content is as following:The calculation formulas were presented in different flexural stages of RC continuous beams strengthened by BFRP considering the secondary loads that before the concrete is cracking,when the concrete is cracking,after cracking but the compressive stress keeps liner and after cracking but the compressive stress is in the elastic-plastic stage.The flexural failure mode of RC continuous beams strengthened by BFRP is studied and the reasonable proposal is given by the layer number of BFRP.The RC continuous beam's yield load,ultimate load and deflection are influenced by initial loads and layer number of BFRP by using the theory analysis.Meanwhile,the accuracy is verified by the simulation of RC continuousbeams strengthened by BFRP by the finite element software ABAQUS.By calculating and observing the strain of steel and BFRP,we can conclude that the strain of steel and BFRP is decreasing with the increase of layers of BFRP sheets;in terms of beams reinforced,the more obvious of the secondary loads,the greater of the strain of steel,the more obvious of BFRP's strain lag.