Effect of incorporating PVC waste as aggregate on the physical, mechanical, and chloride ion penetration behavior of concrete

With the growing needs for resource materials and the environmental protection requirements associated with sustainable development, it has become necessary to study all the possibilities of reusing and recycling industrial wastes and by-products, especially in the field of civil engineering. In the work presented here, non-biodegradable plastic aggregates made of polyvinylchloride (PVC) waste, obtained from scrapped PVC pipes, were used in partial replacement of conventional aggregates in concrete. For this purpose, a number of laboratory prepared concrete mixes were tested, in which natural sand and coarse aggregates were partially replaced by PVC plastic waste aggregates in the proportions of 30, 50, and 70% by volume (granular classes 0/3 and 3/8). Fresh concrete mixtures were tested for workability and density, and hardened concrete specimens were used to investigate compressive strength, ultrasonic wave velocity, and resistance to chloride ion penetration. The results of the laboratory study showed that concrete made with 50 and 70% of recycled PVC aggregates fell into the category of structural lightweight concrete in terms of unit weight and strength properties. This study gave quite encouraging results and opened up a new way of recycling PVC waste as a lightweight aggregate in concrete.