Alternatives to improve the shear behavior of beams made with recycled concrete aggregates

Abstract

Natural aggregates are frequently used in material of the building construction especially in concrete. Researchers discovered recycled aggregates as a substitute environmentally friendly resource. Many studies were investigated about the mechanical characteristics of the recycled aggregates but rare that focused on the shear behavior of these aggregates. These recycled aggregates proved to be weak in mechanical properties, thus diverse types of fibers can be as additives into the concrete mixture to strengthen the concrete’s mechanical and structural behavior. Therefore, in this project, the viability and behavior of reinforced concrete beams built of recycled concrete aggregates (RCA) under shear test is studied experimentally, where the concrete mixture consisted of recycled aggregates in addition to various fibers like Polypropylene fibers “PP”, glass fibers “GF”, and Styrene butadiene rubber “SBR”. An experimentally comparison determined the parameters of five beams constructed with recycled concrete aggregates in addition to various materials in each beam and one beam made with natural aggregates as a control beam. Results were compatible with previous findings and showed that mechanical and shear behavior of RAC can be the better improved by lowering water to cement ratio or notably adding glass fibers, in addition to adding polypropylene fibers or Styrene butadiene rubber (SBR).