Experimental Research On High Temperature Performance And Residual Bearing Capacity Of RC Beams With Corrosion Damage

Building fire,as a kind of disaster loading,often caused casualties and property losses.The research on fire resistance for building structures has become an important topic of domestic and foreign scholars in recent years.R.C.structures are widely used in coastal area due to their material performance and advantages of integrity.While R.C.structures are always damaged as the marine environment in the course of their service life.Therefore it is necessary to study the fire resistance performance for R.C.structures subjected to erosion damage.In this paper,the corrosion to R.C.beams in marine environment is simulated by electrochemical accelerated corrosion,and the initial damage under different conditions is analyzed.As the initial condition,fire tests under the same conditions are conducted to study the regularities of high temperature behavior of beams with different erosion damage.The main research works as follows:1)The results at home and abroad of mechanical properties of RC structures under the single factor of corrosion and fire are summarized respectively,which provides sufficient theoretical basis for the later test and theoretical analysis.2)Three of Four R.C.beams are designed with Faraday's law as the theoretical basis for generating different width of stirrup crack,the fourth R.C.beam as a control to maintain the integrity.3)With the heating standard ISO834,R.C.beams are heated for 120 min.The destruction pattern,section temperature and deflection data are analyzed to explore the mechanical properties of different damaged R.C.beams under high temperature.4)Through the static load test,the destructive mode of R.C.beams is observed.The bearing capacity degradation and deflection of different damaged beams are obtained by comparison5)By using the two-step model,the section of concrete is divided into different zones at different temperature,and the equivalent section method is used to calculate the ultimate residual bearing capacity of R.C.beams after high temperature.By comparing the theoretical and experimental values of residual bearing capacity,the feasibility of model simplification is verified.