Durability Of Reinforced Concrete Beam Streng-thened With Steel Plate Under Load/Hot And Humid Condition

Pasting steel plate reinforced concrete structure is commonly used as a reinforcement method,Paste steel reinforced concrete structure is widely used in the old bridge reinforcement,the environment and load coupling effect will have adverse effects on reinforcing structure,resuLting in lowering the durability of the structure,So the reinforcing structure experiments with coupling load and environmental is significance.This article reLlies on the Ministry of Transport Construction scientific and technological projects "under load and hot and humid environment coupling paste Bridges Durability key technology of reinforcement"(No.2015318814190).This article describes the research status at home and abroad for pasting steel plate durability of the room after,environmental effects,and environmental load coupling effect of experiment beams three point bending test,failure modes of the structure,by the resilience performance,cross-section,to give the reinforcement of structural durability and reduce process-related experiment data.1)Hot and humid environment of bonded steel layer mode of action,vapor in the air into the adhesive layer between the steel plate and concrete,the bonding layer reduces the abiLity to make steel reinforcement paste the failure mode of reinforced concrete beams change.2)In hot and humid environment and load coupLing,hot and humid environment for acceLerated deterioration layer bonding capacity,promote water vapor into the steel plate and concrete layer between the adhesive properties of adhesive will reduce the deterioration of the concrete by water vapor significant role and make cracks at low load to carry,load and hot and humid environment coupling paste accelerated procedure beams steel reinforcement degradation in performance.3)The test beam ultimate strain of duration increase showed a trend of decrease with the hot and humid environment,when the test beam coupling with load and hot and humid environment and steel strain,test beam failure under the action of ultimate strain showed a trend of lower,steel bar strain under load and hot and humid environment effect is smaller.4)In hot and humid environment and load coupling effect,pasted steel plate reinforced concrete beams on crack conduct affected layer is within a certain range of load level,the occurrence of cracks in the beam test small changes,when the shear stress fracture is greater than the glue after the inter laminar shear strength,cracks will continue to expand,pasting steel plate reinforced concrete beams span parts of crack development more dense spacing of less than controls after not reinforced beams B-0d-0KN,loads and humid environment coupling,spacing and crack to carry out changes in circumstances small.5)In hot and humid environment and load coupling effect,the steel cross-section strain tended to decrease with increasing load and humid environment coupling time,reduce the strain of the more obvious,steel participate in the force structure,steel beams to span from stress ends decreases,the stress in the cross section of the free end of the whole process of loading the structure,almost no change in 1#,2# cross-sectional process mainLy involved in the force structure of the steel sheet anchor role fixed limit,steel anchor at the strain is less than elsewhere,indicating that anchor off the transmission path structure of shear stress,the interfacial shear stress mutated at anchor at the instructions for pasting the use of steel reinforcement anchor necessity,can effectively improve the steeL sheet force performance.