Sustainable Use of Red Mud and Reclaimed Asphalt Pavement Wastes in Roller Compacted Concrete: Fid-Bau Portal

Sustainable Use of Red Mud and Reclaimed Asphalt Pavement Wastes in Roller Compacted Concrete

Ram Kumar, B. A. V. / Ramakrishna, G.

Reduce, reuse and recycle are treated as the thumb rule for achieving sustainability, and this formula rightly applies to construction materials as they are depleting at an incredible pace. Reclaimed asphalt pavement (RAP) is a sustainable alternative for construction aggregates. Several researchers have identified RAP as inferior material over natural coarse aggregates and proposed incorporating materials like superplasticizers, admixtures, fibers, and pozzolanic materials to compensate for the decrease in mechanical properties. Thus, the present study aims to evaluate the mechanical and durability characteristics of RAP-based roller-compacted concrete with red mud as part addition to cement. The present study considers a constant replacement percentage of 50% by weight of natural aggregates with RAP to evaluate mechanical and durability properties. Upon comparing the fresh properties of RAP-based roller-compacted concrete with red mud over roller-compacted concrete with only natural aggregates, a 3–15% increase in optimum moisture content is observed. Further, the mechanical properties like compressive, flexural, and tensile strengths, which showed a downtrend due to RAP inclusion, have significantly improved by incorporating red mud. However, a 15% red mud by cement weight is observed to be an optimum dosage based on the mechanical properties. Red mud-inclusive mixes outperformed RAP and control mixes in terms of durability characteristics such as water absorption, abrasion loss, and resistance to the aggressive environment. Further, incorporating 15% red mud in RAP-based roller-compacted concrete liberates a lower calcium silica ratio, which ascertains the dense microstructure formation.