Abstract
This study investigates the fresh, mechanical, and durability performance of a low-carbon Roller-Compacted Concrete (RCC) system produced with a ternary Portland-limestone cement (PLC) binder incorporating 40% ground-granulated blast-furnace slag and 7% silica fume, along with recycled tire rubber as a partial fine aggregate replacement. The objective was to quantify the influence of slag-rich ternary binders and rubber inclusions on compaction behavior, strength development, and permeability of pavement-grade RCC. The fresh properties showed that increasing rubber content from 0% to 8% decreased Vebe time and improved remolding response under vibration due to reduced aggregate interlock, while the slag-modified binder maintained cohesion and prevented segregation at low water contents. Compressive, flexural, and splitting tensile strengths exhibited controlled reductions with increasing rubber dosage, primarily due to rubber’s low modulus, weak interfacial bonding, and disturbance of granular packing. Nevertheless, all mixtures retained strength levels suitable for pavement applications, with the high-slag ternary binder mitigating strength loss through microstructural densification and improved interfacial transition zone quality. Water absorption increased slightly with rubber content but remained low across all mixtures due to pore refinement produced by slag hydration and silica fume. Overall, the results demonstrate that PLC–slag–silica fume binders provide a robust, low-carbon matrix capable of accommodating recycled tire rubber while maintaining the structural and durability requirements of RCC pavements. The synergy between high slag content and rubber modification offers a viable pathway toward sustainable, resource-efficient pavement construction.