Strengths and plastic shrinkage cracking resistance of mortar overlays incorporating steel slag and rubber aggregates for concrete pavement repair

This paper investigated the compressive strength, flexural tensile strength, abrasion resistance, and resistance to plastic shrinkage cracking of mortar overlay for concrete pavements with three sand replacement ratios by volume: control (no incorporation), 30% steel slag (30SSA), 30% rubber aggregates (30RA), and a combination of 15% SSA and 15% RA (15SSA15RA). The results indicate that most mixtures satisfied the flexural strength requirement (> 4 MPa) and exhibited adequate abrasion resistance for all road classifications (< 0.3 g/cm²), except for the mortar incorporating 30% RA, which failed to achieve the required flexural capacity. Notably, the mortar with SSA revealed a higher resistance to plastic shrinkage cracking. The 15SSA15RA mixture, in particular, exhibited no visible cracks, demonstrating its effectiveness in mitigating shrinkage and resulting cracking when incorporating SSA and RA. The findings promotes the application of rubber-steel slag mortar in concrete pavement repair for the sustainable reuse of by-products in road construction.