Investigation of the properties of self-compacting concrete using treated rubber powder, polypropylene fibers, and wash water

The current research addresses a significant environmental challenge in urban areas by focusing on the recycling of waste rubber materials and the reuse of wash water from concrete truck washing. This study investigates the properties of self-compacting concrete (SCC) that incorporates 7 % treated rubber powder and 1 % polypropylene fibers, and wash water. Twelve mix designs were examined, varying in cement content (400 and 440 kg/m³) and water-to-cement ratios (0.36 and 0.5), to evaluate their workability, mechanical properties, and durability. The use of treated rubber powder, compared to its untreated counterpart, enhances the properties of fresh concrete. The designs that included fibers, rubber powder, and wash water exhibited significant variations: a 5 % decrease in slump flow, a 30 % increase in T 50 cm time, a 10 % decrease in J-ring passing ability, a 20 % increase in V-funnel duration, and a 5 % reduction in fill ability compared to the control specimen. Compressive strength in specimens containing polypropylene fibers decreased by an average of 5 %, while those using wash water showed a 6 % reduction compared to control specimens. However, specimens with treated rubber powder demonstrated greater compressive strength than specimens with untreated rubber . The primary designs incorporating fibers, wash water, and treated rubber powder experienced an average 9 % reduction in compressive strength relative to control specimens. Considering tensile strength, there was an average increase of 9 % in specimens with polypropylene fibers and a 2 % increase in those with rubber powder. Additionally, specimens containing wash water exhibited a 4 % average increase in tensile strength. Flexural strength decreased by 3 % in specimens with fibers and by 4 % in those with rubber powder. Finally, designs that included both treated and untreated rubber powder along with polypropylene fibers showed higher volumetric water absorption compared to the control designs. • Mechanical and durability properties of self-compacting concrete with propylene fiber. • The use of wash water, treated tire powder, and propylene in self-compacting concrete. • Impact of wash water, tire powder, and propylene on self-compacting concrete workability.