Advanced Reclaimed Asphalt Pavement Treatment for Sustainable Pervious Concrete: Optimizing Strength, Hydraulic Performance and Long-Term Durability

Reclaimed Asphalt Pavement (RAP) Pervious Concrete Compressive Strength Flexural Strength Permeability Durability Microstructural Analysis.

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The increasing depletion of natural aggregates and escalating construction waste necessitate the implementation of environmentally friendly substitutes in concrete production. This study explores the incorporation of treated Reclaimed Asphalt Pavement (RAP) as an eco-efficient alternative to traditional coarse aggregates in pervious concrete (PC) matrices by evaluating its structural integrity, permeability, durability, and microstructural characteristics. A comprehensive multi-stage treatment process involving solar heating, natural oxidation, and mechanical roughening was employed to enhance aggregate bonding and bitumen reduction. The treatment of RAP was conducted for three treatment durations: 0-month, 12 months, and 24 months. Coarse aggregates were substituted with 0%, 25%, 50%, 75%, and 100% RAP by weight, and all mixtures were cured for 90 days. The investigation focused on evaluating essential functional characteristics, including density, porosity, hydraulic conductivity, compressive and flexural responses, as well as durability under abrasion and chemical exposure to sulphate and chloride environments. Microstructural analysis utilizing Energy Dispersive X-ray Analysis (EDAX) demonstrated a substantial reduction in bitumen content, as evidenced by a declining carbon peak with increased treatment duration. Additionally, Scanning Electron Microscopy (SEM) micrographs revealed fewer voids, increased C-S-H formation, and improved bonding, with minor Interfacial Transition Zone (ITZ) variations across 12-month and 24-month treatments. The findings highlight that extended RAP treatment significantly improves density, reduces porosity, enhances compressive and flexural strength, and lowers permeability. Furthermore, 24-month treated RAP demonstrated superior durability, exhibiting enhanced abrasion and chemical resistance due to improved aggregate cohesion and matrix integration. This study establishes that pervious concrete with more than 50% RAP content, previously considered unviable, is structurally feasible when suitable treatment and gradation techniques are used, thereby advancing sustainable construction materials.

 

Doi: 10.28991/CEJ-2025-011-04-019

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