Iron slag pervious concrete for reducing urban runoff contamination

Abstract

This study investigates the engineering properties of Iron Slag Pervious Concrete (ISPC) along with its ability on reducing urban runoff contaminations. For this reason, different proportions (up to 15%) of fine-grained iron slag (0.6–1.2 mm) were added to pervious concrete mixture design. With regarding to mechanical characteristics ISPC with 15% of iron slag (IS15) had the better performance by improving the average fresh density (9%), and strength (compressive (16.12%), flexural (10.28%), tensile (9.23%)). However, a decreasing in slump (41.17%), permeability (16.19%) and porosity (15.29%) was observed compared to that of the control sample. Also, the average cementitious paste thickness declined as the iron slag added to ISPC mixture. Apart from this, IS15 had a better performance in reducing urban runoff contaminations, due to having a porous nature and decreasing the size of pores in ISPC to capture more pollutants, in which Chemical Oxygen Demand, Total Suspended Solids, and turbidity declined by 69.75%, 68%, and 69%, respectively. Overall, IS15 mixture, which requires a little lower cost of mixing and implementation than conventional concrete, is recommended to be applied in urban areas with low traffic loads to collect urban runoffs and enhance its quality.