Recycled Concrete Beam Flexural Performance Test Study And Nonlinear Finite Element Analysis

With the rapid development of urbanization，the increasing discharge of wasteconcrete not only cost large sums of money, but also affect the environmental landscape.Large amount of concrete and aggregate is needed in urban construction, while theover-exploitation of natural gravel has caused serious damage to the ecologicalenvironment. Using waste concrete to produce recycled concrete can well solve the aboveproblems. As recycled concrete technology coincides with China’s sustainabledevelopment strategy, this kind of green concrete will be a development direction for thefuture concrete.Firstly, this article studies the recycled concrete’s mechanical properties, whoserecycled coarse aggregate replacement rate is0%,30%,75%; Secondly, with samewater-cement ratio, same reinforcement ratio but different recycled coarse aggregatereplacement rate of0%,30%,75%,3recycled concrete simply supported beams’ flexuralperformance is analyzed, and the normal section force-deformation properties and failurecharacteristics are also analyzed; Last, using ABAQUS to establish the recycled concretebeam finite element model and Calculate the deflection, cracking load and ultimate load,which is compared with experiment values. The following ideas are concluded:(1) The slump constant increases as the recycled coarse aggregate replacement rateincrease; the compressive strength, tensile strength and modulus of elasticity of recycledconcrete are lower than normal concrete.(2) The failure process and failure mode of recycled concrete reinforced beams arebasically the same with normal concrete beam; The average strain of normal section obeysthe plane section assumption; Under the same condition, compared with normal concretebeam, the cracking load, yield load and ultimate load decrease as the recycled coarseaggregate replacement rate increase, the maximum crack width and the mid-spandeflection of recycled concrete beam are larger than normal concrete beam, while themaximum crack depth is lower than normal concrete beam. Test and theoretical analysisindicate that recycled concrete beam’s cracking moment calculation does not apply toexisting norms and need to be fixed. However, recycled concrete beam ultimate momentcalculation is suitable for the existing norms.(3) The finite element model of the recycled concrete beam is established using the ABAQUS, it can be seen that the trend recycled concrete beams’ mid-span deflection issame with the test results as the load changes. With the increasing of recycled coarseaggregate replacement rate, the deflection of recycled concrete beam gradually increase,while the cracking load and the flexural capacity decrease.