Experimental Study On Restoring Force Characteristics Of Steel Reinforced Recycled Concrete Frame Infilled With Recycled Concrete Hollow Blocks

Steel reinforced recycled aggregate concrete is a new type of structural system, itsmajor configuration is steel and comes with a certain degree of reinforced steel andstructural steel in recycled aggregate concrete.It combines the advantages of steelreinforced concrete and recycled aggregate concrete. Especially in recent years,concrete occupation of natural resources and burden on natural resources caused byconcrete increasingly heavily. That make recycling abandoned concrete necessary. Steelreinforced recycled aggregate concrete not only makes full use of the abandonedconcrete, saving resources,but also provides a feasible solution for the promotion ofrecycled aggregate concrete in structural engineering, it has a very large commercialvalue and ecological value.Based on the experimental study on seven model of steel reinforced recycledaggregate concrete frame infilled with recycled concrete hollow blocks under low cyclicreversed loading, the process of force, the failure modes, the features of structure, theskeleton curves, the hysteretic curves, displacement ductility, energy dissipation andstiffness degradation were investigated. Analysis indicate that: The infilled walls failearlier than the main frame and the failure mechanism is the beam-hinged mechanism.The infilled walls enhance the lateral stiffness and load carrying of the structural,increase the speed of stiffness degradation, decreases displacement ductility. With theincrement of axial compression ratio, the load carrying capacity increases, displacement ductility decreases, initial stiffness increases and the speed of stiffness degradation turnfast. With the decrease of the infilled blocks strength, load carrying capacity decreases,displacement ductility increases, initial stiffness decreases, the speed of stiffnessdegradation turn slow. With the decrease of lacing rebar spacing both load carrycapacity and displacement ductility increases slightly, initial stiffness increase, the speedof stiffness degradation keep almost constant. The load carrying capacity and initialstiffness of the frame with half-height infilled walls are between those of bare frame andframe with full-height infilled wall, and its displacement ductility and energy dissipationare close to bare frame. With the increase of width-height ratio of infilled wall, loadcarrying capacity and initial stiffness increase, the displacement ductility decrease, thespeed of stiffness degradation increase.On the basis of the experimental research, for the five models of frame withinfilled wall (the frame with full-height infilled wall, axial compression ratio of0.6, theframe infilled with fly ash blocks, lacing rebar spacing200mm, width-height ratio ofinfilled wall2.2), the test data were fitted by Origin8.0software and then got thedimensionless skeleton curves model that consider the influence of various parameters.Through further regression analysis, the positive and negative stiffness degradation ruleof unloading and reloading were proposed, Ultimately, with combination of thedimensionless skeleton curves model, the stiffness degradation and hysteretic rules, therestoring force model of steel reinforced recycled concrete frame infilled with recycledconcrete hollow blocks was proposed, then calculate skeleton curve model of eachmodel. The comparative analysis of calculated and measured skeleton curves show that,this model fitts better and can be used on elastic-plastic seismic response analysis ofsteel reinforced recycled concrete frame infilled with recycled concrete hollow blocks.