Durability and internal curing performance of roller compacted concrete incorporating brick fine aggregate as recycled material

Abstract

Roller Compacted Concrete (RCC) is susceptible to self-desiccation due to its low water-to-cement ratio, which prematurely limits cement hydration, while its dense zero-slump matrix reduces the effectiveness of conventional surface curing. This study investigates the use of Brick Fine Aggregate (BFA) as a partial replacement for natural fine aggregate in RCC, with emphasis on internal curing potential and abrasion resistance. BFA obtained from locally demolished masonry structures exhibited a 72-hour water absorption of 19.74% and a desorption capacity of 86.8%, confirming its suitability as an internal curing aggregate. Replacement levels of 10%, 15%, and 20% were systematically determined based on internal curing water demand, unlike previous studies that adopted empirically selected replacement levels. The RCC mix was designed in accordance with soil compaction principles, with a fixed cementitious content of 12%. Compressive strength was evaluated at 3, 7, and 28 days, while underwater abrasion resistance was assessed over 72 hours. The control mix achieved a 28-day compressive strength of 40.70 MPa. The 20% BFA mix yielded a 63% improvement in 3-day strength and achieved 37.15 MPa at 28 days, while the 10% mix recorded the lowest strength of 27.00 MPa. The 15% BFA mix recorded the highest abrasion loss, approximately 91% greater than the control, while the 10% and 20% BFA mixes recorded cumulative volume losses approximately 44% and 46% greater than the control respectively, confirming that enhanced paste densification through internal curing at 20% replacement compensates for the mechanical weakness of brick aggregate. Overall, 20% BFA replacement demonstrated the most favorable durability performance, confirming that brick C&D waste can be effectively utilized in RCC as both a recycled aggregate and an internal curing agent for sustainable pavement construction.