Structural Behavior of Recycled Aggregate Concrete Continuous Beams

Abstract

The structural behavior of continuous recycled aggregate concrete (RAC) beams under point loading at each span is examined experimentally in this work. Nine continuous beams, each 225 mm deep, 150 mm wide, and 3000 mm long, were tested as part of the program.
As references, there were two beams made of normal concrete, one intended for shear failure and the other for flexural failure. Three beams were cast with different replacement ratios of recycled concrete Aggregate (20%, 40%, and 70%) to assess the effect of RAC content. The impact of RCA placement was also investigated using two flexure-critical beams and two shear-critical beams, each developed with a particular recycled aggregate location. The main experimental parameters included steel fiber, the position of recycled Aggregate, and the ratio of recycled aggregate replacement.

According to the results, recycled Aggregate reduced the ultimate load by up to 5.38%. On the other hand, the ultimate load increased by as much as 10% when steel fiber was added. Additionally, flexural strength was reduced by up to 10% when recycled Aggregate was moved within beams intended for flexural failure. In contrast, shear-critical beams had a shear strength drop of up to 23% when the same modification was made.