Research On Flexural Behavior Of Steel Reinforced High Performance Recycled Concrete Composite Beams

With the increasing requirements of people on the environment, the waste concrete's reuse has attracted more and more people's attention. At present, the research in the field still exist a large number of blanks because the recycled concrete's research and application is still in the initial stage. In order to provide a theoretical basis for the application of the recycled concrete in combination structure, in this experiment, the high strength-high performance recycled concrete and the flexural performance of Steel Reinforced High Performance Recycled Concrete (SRHPRC) beams are studied basing on the experiments of 9 groups of recycled concrete specimens and 3 steel reinforced high performance recycled concrete beams.The main work is as follows:1 In order to research the different pretreatment methods on the strength effect of the recycled concrete, the recycled aggregate is treated by three different methods, and then, we prepare the concrete by the same ratio and the same recycled aggregate replacement rate. The study shows that recycled aggregate wrapped treatment method has little influence on concrete strength and workability, the water immersion has little influence on recycled concrete strength too, but the water immersion can significantly improve the workability.2 In order to research the influence of recycled aggregate replacement rate on compressive strength and working performance of concrete, we make concrete according to the different displacement ratio of recycled aggregate (40%,55%,70%,85% and 100%) respectively. The study shows that the compressive strength of recycled concrete decreases with the replacement rate increasing, but replacement rate has little influence on the workability of recycled concrete.3 In this paper, we studied the failure process of steel reinforced high-performance recycled concrete beams and analyzed the deformation characteristics of steel reinforced high performance recycled concrete beam in the elastic stage, cracking stage, yield damage stage.4 The usability of steel reinforced concrete beam bearing capacity calculation method on steel reinforced recycled concrete beam is analyzed through the flexural bearing capacity calculation method of Specification for Design of Steel-Reinforced Concrete Structure.5 In this paper, we analyzed whether the rigidity calculation method of Technical Specification for Steel Reinforced Concrete Structure is applicable to steel reinforced recycled concrete beam's rigidity calculation. For researching the influence of the section steel and the high performance recycled concrete on the rigidity of recycled concrete beam, we compared the deflection deformation between the recycled beam and the ordinary concrete beam. 6 This paper researched the usability of recycled concrete on composite structure. After the high performance processing, the recycled concrete's strength can meet the specification requirement, the recycled concrete's working performance is good, and the recycled concrete can meet the requirement of commodity concrete. SRHPRC beams can play the advantages of both steel and recycled concrete.