Investigation on Bond Strength of Recycled Aggregate Concrete Using Crumb Rubber and Polypropylene Fiber as Partial Replacements for Conventional Construction Materials

In the era of rapid technological progress, managing construction and demolition wastes poses challenges to achieving sustainable development goals. This research explores using recycled coarse aggregate (RCA) and waste materials like crumb rubber (CR) for construction. By combining these materials with polypropylene fiber (PPF), a new approach is proposed to promote green construction practices. The study analyzes the bond strength of concrete with RCA, CR, and PPF, replacing portions of natural coarse and fine aggregates. This research utilized the pull-out method for observing and analyzing the bond strength performance of concrete consisting of RCA, CR, and PPF. Natural coarse aggregate (NCA), natural fine aggregate (NFA), and cement were partially replaced by recycled coarse aggregate (10 and 30%) on a weight basis, crumb rubber (5 and 10%) on a volume basis, and polypropylene fiber (2%) on volume basis, respectively. Different steel reinforcement lengths and diameters are tested. It is recommended that the replacement of 30% NCA with RCA and 2% cement with PPF without replacing NFA by CR can be executed in construction without compromising the safe margin of concrete bond strength. This research encourages sustainable development and the use of recycled materials in construction.