Experimental Study On Bending Behavior Of Reinforced Concrete Beams Strengthened With Stainless Steel Plate

Reinforced concrete structures are widely used in the field of construction engineering,but with the improvement of people’s requirements for building functions,the increasing tension of urban land and the aging and damage of existing structures,it is necessary to reinforce them in order to meet the existing use requirements.There are many reinforcement methods for existing reinforced concrete structures.Although the bonded steel reinforcement method has the advantages of convenient construction,short construction period,maintenance process without affecting production and occupying less use space,the existing bonded steel plate reinforcement method uses carbon steel plate which is easy to rust,poor durability and poor fire resistance,resulting in high maintenance costs in the later period,thus further restricting its application.The stainless steel has good corrosion resistance,durability and fire resistance,and is beautiful and generous.With the promulgation of the design code for stainless steel structure,its application in construction projects will be more and more extensive.If stainless steel plate can be used instead of carbon steel plate,bonded steel reinforcement technology can be better adapted to bridge,harbour and underground reinforcement projects which require high durability,corrosion resistance and later maintenance.Firstly,according to the research status of reinforced concrete beams strengthened with ordinary steel plates and the characteristics of stainless steel materials,the influencing factors of flexural performance of reinforced concrete beams strengthened with stainless steel plates are proposed.Secondly,aiming at the factors affecting the flexural performance of reinforced concrete beams strengthened with stainless steel plates,12 specimens of reinforced concrete beams were made,and the static load tests were carried out,and the phenomena and test results of each specimens were analyzed and summarized.The results show that stainless steel plate can cooperate with steel bar;the stiffness,cracking load and ultimate load of reinforced concrete beams strengthened by stainless steel plate can be increased in different extent,and the greater the thickness of steel plate,the greater the range of increase;and stainless steel plate can effectively inhibit the development of cracks in concrete beams.Thirdly,the finite element software ABAQUS is used to establish the numerical model of reinforced concrete beams strengthened with stainless steel plates,and the feasibility of the model is verified by comparing with the experimental results of reinforced concrete beams strengthened with stainless steel plates,which are in good agreement.Then,10 specimens of concrete beams strengthened with stainless steel plates were designed,taking the strength of concrete,the thickness of adhesive layer and the loading mode as the parameters.The bending results show that the higher the strength of concrete,the greater the yield load and ultimate load;with the increase of the thickness of the adhesive layer,the stiffness of reinforced concrete beams strengthened with stainless steel plates increases slightly,but the increase is not significant;the bending capacity of reinforced concrete beams strengthened with stainless steel plates under single point concentrated loading is the lowest,and the bending capacity under four-point loading is the highest.The structure tends to be brittle and unstable if the distance between two loading points is too long.Finally,the peeling failure mechanism of reinforced concrete beams strengthened with stainless steel plates is analyzed and summarized.The formulas for calculating the first and second bending capacity of reinforced concrete beams strengthened with stainless steel plates and the coefficients of steel and steel plates working together are put forward,and the formulas for calculating the maximum amount of steel bonding are given.