Shear Behavior of Recycled Coarse Aggregates Concrete Dry Joints Keys Using Digital Image Correlation Technique

Abstract

In this work, twenty-seven dry joint specimens of prestressed segmental bridges produced using recycled coarse aggregate concrete (RAC) were subjected to push-off tests. The substitution rate of coarse aggregate for recycled aggregate was 100%. The variables observed were the number of keys, including flat, single-keyed, and three-keyed, and the magnitude of the confining stress, varying at 1.0, 2.0, and 3.0 MPa. The slippage between both parts of the joint and the cracking of the specimens were analyzed using the digital image correlation technique (DIC). Equations from the literature were used to predict the shear strength of dry joints with recycled coarse aggregate concrete. The experimental results obtained from the present research were compared to those of other conventional concrete researchers. The results showed that the dry joints produced with recycled coarse aggregate concrete presented a crack formation in conventional concrete joints following a similar mechanism of failure; however, they presented lower strength. Some equations in the literature predicted the strength of dry joints with recycled coarse aggregate concrete. Based on the analysis performed, adopting a reduction coefficient of 0.7 in the AASHTO normative equation was recommended for predicting the shear strength of dry joints when produced with recycled coarse aggregates concrete.