Experimental Research On The Flexural Behavior Of Recycled Course Aggregate Concrete Beams

With the rapid development of the building industry, the waste of building have been growing day by day. and most of them are waste concrete. Besides the charge for an abundance of waste disposal is very much, it also is harm to the environment and society, In addition, the large demand of concrete request the exploitation of natural resources-sand and stone, and so the natural resources has been on the exhausted edge for the unceasing exploitation. Moreover, besides the exploitation and transportation of natural sand and stone expands largely, it also destroys the environment badly. The recycled concrete based on environment protection and sustaining development can settle the problem.Based on bending comparison experiment of five recycled concrete beams and one normal concrete beam, analyze recycled the influence of concrete and reinforcement ratio no the recycled concrete beams' bending performance, failure modes, deformation characteristics, and study the flexural capacity, crack resistance, crack width and deflections under serviceability limit states.Based on the experimental results, the following conclusions are drawn. In bending, the recycled concrete beam also has elastic, cracking, yield and ultimate point. The average strain measured on cross-section obliges to the plane section assumption. Under same conditions, the cracking and ultimate moment of recycled concrete beam are similar to conventional concrete beam, however, the stiffness of recycled concrete beam reduces somewhat.At the end of this paper, after verifying the formula suggested by present code for Design of Concrete Structures (GB50010-2002) for recycled concrete beams, a conclusion can be drawn that the ultimate moment and the cracking moment of recycled concrete beam can be estimated by the formula suggested by present code, whereas, the width of crack and the deflection can not. Finally, according to the result of experiment discusses correction method for short-term stiffness of recycled aggregate concrete beams.