Study On Performance Of Corroded Reinforced Concrete Beams Under Impact Loading

With the development of ocean developing industry,more and more concrete structures are applied to the construction,such as wharves and cross-sea bridges.However,concrete structures in service environment such as ocean and seashore for long are corroded by chloride ion,which leads to durability reduction and decrease of service life.Structures might be crashed by vessels.Impact loads may bring permanent deformation to structural members or even destroy them.Therefore,it is of important significance to predict the dynamic response of corroded RC beams subjected to impact actions.The main contents are as follows.Firstly,14 RC beams under combined action of load and chloride drying and wetting cycles were carried out.The main parameters are corrosion time and transverse crack width so that specimens with different corrosion level were obtained.Then experimental work of these corroded specimens subjected to impact actions was done with the drop hammer rig.Failure modes,impact force curves,mid-span deflection curves and strain curves were recorded in the tests.The influence of different parameters on the dynamic response of corroded RC beams subjected to impact actions were obtained.Secondly,a finite element analysis model was established to predict the dynamic response of corroded RC beams subjected to impact actions,in which the strain rate effects of materials and the reduction in strength of materials caused by corroded reinforcement on were considered.The bond-slip relationship between corroded reinforcement and concrete was also simulated in the FEA model.Test data from the author and other researchers were used to verify the accuracy of the FEA model and general good results were achieved.Thirdly,the FEA model was used to study the mechanical behavior of corroded RC beams subjected to impact actions,which includes the failure mode,impact force,mid-span deflection,section moment and shear,and stress development.Fourthly,the influences of longitudinal reinforcement corrosion level on the mechanical behavior of corroded RC beams subjected to impact actions were studied,including reaction force curves,mid-span deflection curves,moment curves and shear curves.The influence of longitudinal reinforcement corrosion level on the mechanical behavior of corroded RC beams subjected to impact actions were obtained.Finally,a simplified calculation method was drawn on the which can be used in the design of corroded RC beams under subjected to impact actions.Test data from the author and other researchers were used to verify the simplified calculation method and general good results were achieved.