Durability and compressive strength of composite polyolefin fiber-reinforced recycled aggregate concrete: An experimental study

This study investigates of using recycled concrete aggregates along with the reinforcement of polyolefin fibers to augment both the compressive strength and durability of concrete, in alignment with the principles of sustainable development. This study experimentally investigated the compressive strengths and durability of composite polyolefin fiber-reinforced recycled aggregate concrete (PFRRAC) exposed to chloride and acidic environments. For this purpose, 150 cubic concrete samples of 100 × 100 × 100 mm with various combinations of recycled aggregates and polyolefin fibers were made and subjected to axial compressive loading. The results show that the addition of fibers significantly enhances the compressive strength of concrete, with an increase of up to 34.36 % at 5 % fiber content. However, increasing the proportion of recycled aggregates reduces the compressive strength, with reductions ranging from 21.12 % to 43.85 % as the recycled aggregate content rises to 70 %. Moreover, the combination of fibers and recycled aggregates demonstrates potential for improving the sustainability and durability of concrete under challenging environmental conditions, particularly in chloride and acidic environments. In acidic environments, the inclusion of fibers significantly enhances the resistance to strength reduction. Furthermore, the study uncovers that a higher concentration of recycled aggregates exacerbates the reduction in strength in chloride-rich settings, emphasizing the imperative nature of meticulous mix design and material selection. The findings for the integration of even minor quantities of polyolefin fibers to amplify the performance and sustainability of concrete mixtures, especially when utilizing recycled aggregates, thus promoting eco-friendly construction practices.