Experimental Research On Seismic Behavior Of Square Steel Tubular Columns Filled With Recycled Aggregate Concrete

The reuse of waste concrete is a problem to be addressed, which is in accordance withthe strategies of both sustainable development and environmental protection of ourcountry. Due to performance limitations of recycled aggregate concrete (RAC), the useof RAC is still relatively low, which usually use as self-bearing members in the projectat the present stage. In order to approach to the application field of RAC in compositestructure, use recycled aggregate rather than natural aggregate to make encasedstructures. This kind of structure, which RAC is under the constraints of steel, makingthe bearing capacity and durability improved. For this reason, steel tubular filled withrecycled aggregate concrete can be regarded as a new application way in the project.At present, scholars at home and abroad are mostly focusing on the axial compressionexperiments of square steel tubular columns filled with recycled aggregate concrete,while the seismic behavior is still waiting for researches. Therefore, an experiment onseismic behavior is carried on.Experiment of three full-scale square steel tubular columns, which filled with RACunder constant axial load and cyclic lateral load were done, and influences of bothreplacement ratio of recycled aggregate concrete and steel ratio on the seismic behaviorof the specimens were investigated. Specimen’s mechanical behavior and failurecharacteristics have been known from the test, and the hysteresis curves, skeleton curves,deformation performance and energy dissipation capacity of the specimens have beengotten. Results show that square steel tubular column filled with RAC has a goodseismic behavior. With the increasing of steel ratio, the ultimate load increasesconsiderably, along with ductility and energy dissipation capacity increase. While theultimate load, ductility and energy dissipation capacity reduce slightly with theincreasing of replacement ratio of recycled aggregate.Three specimens’ numerical simulation has been made by ABAQUS. The skeletoncurves calculated by ABAQUS were coincides well with the experimental ones.Through analyzing, the influence rule of both wall thickness and replacement ratio ofrecycled aggregate to the skeleton curves by simulation analysis gained a goodconsistency with the experimental results. Based on the conclusion of finite elementanalysis, a compare to these two parameters’ influences on the skeleton curves was doneunder the circumstance of changing the values of both wall thickness and replacement ratio of recycled aggregate. The experimental results and calculated results were alsocompared. At the end of this article, three specimens’ N-M relative curve equations werededuced in a theoretical way. And on this basis the horizontal bearing capacity has beencalculated, then compared to the experimental bearing capacity.