Title:
Mixture Design of Recycled Aggregate Concrete Based on Particle Packing and Excess Paste Theory (Prepublished)
Author(s):
Miras Mamirov, Jiong Hu, and Tara Cavalline
Publication:
Materials Journal
Volume:
Issue:
Appears on pages(s):
Keywords:
excess paste theory; mixture design; particle packing; recycled aggregate; shrinkage; strength; workability
DOI:
10.14359/51749330
Date:
11/20/2025
Abstract:
Several approaches are currently used to proportion recycled aggregate concrete (RAC), each having limitations. An effective and universal way to proportion RAC is not only an important tool for developing high-quality concrete but also a critical milestone for promoting the wider use of recycled concrete aggregate (RCA) in concrete. A mixture design method based on particle packing and excess paste theory is proposed in this study. Given the focus on pavement concrete, the modified Box Test was used to quantify RAC workability. RAC mixtures with five different RCAs of varying quality, developed using the proposed method, showed excellent workability (Box Test Rating E1-S1), whereas mixtures developed with conventional mixture design methods failed to achieve adequate workability. Mechanical properties of optimized RACs were either comparable or improved. The adverse effect of RCA on concrete resistivity and shrinkage appeared negligible and was mitigated by the mixture design approach developed in this study. Compared with conventional Direct Weight Replacement (DWR)/Direct Volume Replacement (DVR) mixtures, the proposed design achieved a reduction of surface voids by more than 80%, up to 25% higher compressive strength, and 20% lower shrinkage at 28 days, while maintaining comparable resistivity.