MECHANICAL AND HYDRAULIC PERFORMANCE OF PERVIOUS RECYCLED AGGREGATE GEOPOLYMER CONCRETE

The widespread expansion of the global economy and the increase in human population have been major contributors to pollution and environmental complications. Construction and demolition wastes (CDW), impervious pavement surfaces, and industrial waste disposal sites have emerged as serious environmental challenges over the past decade. These challenges must be addressed through the synergic use of different sustainable practices, including pervious surfaces, CDW, and industrial wastes. Their combined utilization produces a pervious geopolymer concrete made with recycled concrete aggregates (RCA). This research aims to develop and assess the mechanical and hydraulic properties of pervious geopolymer recycled aggregate concrete (PGRAC) with a design porosity of 15%. The mixes were made with two binder blends of ground granulated blast furnace slag and fly ash (1:0 and 1:1) and RCA replacement of 0 and 100%. The mechanical and hydraulic performance were characterized by compressive strength and permeability, respectively. Results showed that pervious concrete made with natural aggregates and comprising a binder blend of slag:fly ash of 1:0 demonstrated 36% higher compressive strength than counterparts having a binder blend of 1:1. Meanwhile, the permeability was unaffected by the variation in the binder. At 100% RCA, the compressive strength of mixes having a binder blend of 1:0 was 192% higher than that of the equivalent mix having a binder blend of 1:1. Yet, the latter had 12% higher permeability than the former. These research findings demonstrate the ability to produce sustainable PGRAC for use in pavement applications.