高掺入量再生骨料混凝土梁正截面受弯性能试验

Experimental Research on Bending Behavior of High Incorporation of Recycled Aggregate Concrete Beams

目的研究高掺入量再生混凝土梁正截面受力变形性能和破坏特征与普通混凝土梁的差别.方法参照普通混凝土配合比设计方法配制再生粗骨料混凝土,采用相同尺寸和配筋率制作了12根再生混凝土简支梁和3根普通混凝土简支梁,进行静力加载试验.结果再生骨料混凝土梁在受力过程中经过了明显的弹性、开裂、屈服、极限4个阶段.再生混凝土梁的极限弯矩小于普通混凝土梁,掺入量为50%、60%、70%、80%的梁,最大承载力比普通混凝土梁分别下降了11%、12%、15%、16%.结论采用现行《混凝土结构设计规范》公式来计算高掺入量再生混凝土梁的极限弯矩、开裂荷载、挠度依然是可行的.

The goal of the paper is to research the difference between the deformation properties of normal section and destruction characteristic of the recycled concrete beam and that of the normal concrete beam.Recycled coarse aggregate concrete based on the mix ration of normal concrete,the research adopts the method of testing the flexural performance of 12 recycled aggregate concrete beams and 3 natural aggregate concrete beams with the same section size,same percentage of reinforcement and axial compressive strength but different replacement ratio of recycled coarse aggregate.The results of the test show that there are still 4 phases of elasticity,cracking,yield and ultimate as the normal concrete beam.However,ultimate moment of recycled concrete beam is less than normal concrete beam,when the replacement ratio increasing to 50%,60%,70% and 80%,the maximum loading capability decreasing by 11%,12%,15% and 16% respectively.It is still feasible to calculate the ultimate bending moment and the cracking moment,the deflection of recycled concrete beam according to the formula in the ‘Concrete Structure Design Code’ in our country.