Experimental Study And Numerical Simulation Of Flexural Behavior Of Recycled High-strength Reinforced Concrete Beams

Since the 1990 s,China's construction industry has developed rapidly,but at the same time,a large number of construction waste can not be disposed of,compared with Japan in the 1970 s on the formulation of recycled concrete standards.In the Code for Design of Concrete Structures(GB50010-2010),235 MPa-grade lowstrength steel bars were eliminated,500 MPa-grade high-strength steel bars were added,400 MPa-grade steel bars were taken as the main steel bars,500 MPa-grade steel bars were advocated,and 335 MPa-grade steel bars were phased out.The trend of developing high-strength steel bars in China can be seen.Therefore,in the above two backgrounds,combined with recycled concrete and high-strength steel bar,the physical test and numerical simulation test were done,and the two were compared and analyzed.First of all,through physical experiments we can conclude that the flexural properties of recycled concrete beams and ordinary concrete beams are consistent.However,the average deflection of recycled concrete beams rich in brick is obviously different from that of ordinary concrete beams.In terms of crack width,the crack width of recycled concrete beams will be wider than that of ordinary concrete beams,and the crack spacing of recycled concrete beams will be smaller than that of ordinary concrete beams.Secondly,the ultimate bearing capacity of recycled concrete beams can be found to be basically the same by comparing the calculated values with the experimental values and the simulated values of ABAQUS.However,the maximum deflection of recycled concrete beams is too large,which indicates that the checking method of concrete beams under the current code needs to be revised.Finally,the stiffness correction coefficient ? =0.86 is proposed,empirical calculation shows that the stiffness correction coefficient is more consistent.Then the crack simulation is carried out by using ABAQUS software.The simulated maximum crack width is basically the same as the test value.The measured crack moment is in good agreement with the calculated value,the simulated value and the calculated value.The crack moment can be calculated according to the current Code for Design of Concrete Structures(GB50010-2010).Finally,the stiffness correction coefficient is proposed.But the mechanical properties of recycled concrete beams with high strength steel bars are significantly changed after increasing the reinforcement ratio.