Aggregate Interlock and Shear Transfer Mechanism in Recycled Aggregate Concrete

Abstract:

Based on the tests of pre crack push off specimens, the aggregate interlock and shear transfer performance of recycled aggregate concrete (RAC) were investigated. The experimental results reveal that the shear transfer performance across cracks in RAC is similar to that in natural aggregate concrete. When the constraint stiffness is larger, the shear transfer strength of RAC is also higher. With the increase of the RAC strength, the shear transfer strength of the specimen is improved but not obviously. Under the same strength of concrete, the shear transfer strength of specimens decreases slightly with the increase of recycled coarse aggregate replacement ratio, but it decreases marginally. On the basis of Walraven’s investigation and a consideration of the meso structure of RAC as well as the geometry shape of recycled coarse aggregate, an aggregate interlock model for RAC is developed. The shear transfer strength values of each test specimen and the values calculated by the theory agree well with each other.