Influence of Slurry Impregnation Technique of Recycled Concrete Aggregates on the Roller Compacted Concrete Pavement

Utilization of recycled concrete aggregate (RCA) as an alternative aggregate for Roller Compacted Concrete Pavement (RCCP) can help to alleviate the demand for pristine aggregate (PA). However, the adhered mortar (AM) micro-cracks and weak interfacial transition zone (ITZ) need to be addressed/improved to enhance the performance of RCCP. In the present study, the ITZ between RCA and the AM is enhanced following the slurry impregnation (SM) technique using silica fume (SF), fly ash (FA), and cement (CS) slurries. The coarse PA is replaced with treated RCA after the SM technique to utilize RCA in RCCP effectively. Further, control and slurry-treated RCCP mixes were designed using the soil-compaction method by evaluating the optimum moisture content and maximum dry density. Subsequently, RCCP specimens were fabricated using a gyratory compactor to mimic the field compaction behavior. Strength (compressive strength and split tensile strength) and durability properties (water absorption, surface resistivity, and porosity) were considered to assess the efficacy of the SM technique. Notably, all the slurry-treated RCCP mixes exhibited higher compressive strength and split tensile strength than the untreated RCA mix. Similarly, significant improvements were also found in the durability properties of slurry-treated RCCP mixes.