Novel eco-efficient Two-Stage Concrete incorporating high volume recycled content for sustainable pavement construction

A novel eco-efficient technology for the construction of pavements and sidewalks using high recycled volume Two-Stage Concrete is proposed. Two-Stage Concrete is a special type of concrete, which is distinguished by its high coarse aggregate content and exceptional placement, whereby aggregates are first pre-placed in the mold then injected with a special grout. In this study, recycled concrete aggregate and scarp tire rubber granules were used as the preplaced material then injected by high-volume fly ash grout. Moreover, for the first time, steel wire fibers from scrap tire were used as reinforcement in Two Stage Concrete. The performance of such “green” and novel pavement construction technology in terms of mechanical properties, including compressive strength, modulus of elasticity, flexural strength and toughness, as well as durability to freezing-thawing cycles were investigated. The results demonstrate the feasibility of this eco-efficient technology to produce durable and cost-effective sidewalks and pavements, offering ease of placement and superior sustainability features.