Development and Performance Evaluation of Sustainable Composite Wall Cladding Integrating Recycled PET, Waste Tire Steel Fibers, and Rice Husk Ash (RHA)

Abstract

The accumulation of polyethylene terephthalate (PET) waste, vehicle tires, and rice husk ash (RHA) presents a critical environmental challenge in developing countries. This study explores a sustainable composite wall cladding that integrates recycled PET as a polymeric binder, river sand, waste tire steel fibers (SFs), and RHA fillers. Material characterization (XRF, thermal analysis) confirmed a high silica content in RHA (91%) and sand (82%), with a PET melting threshold of 240-255°C. The composites were fabricated through a hot-mixing process at 250°C, while maintaining constant PET and SFs content, systematically varying the RHA-to-sand substitution ratio from 0% to 20% by weight. The experimental results demonstrated that enhancing RHA concentration typically reduced density (from 2.469g/cm3 to 1.495 g/cm3) due to low specific gravity of the ash. While water absorption slightly enhanced (1.8% to 3.12%), values maintained the ‘’Vitreous’’ range of ASTM C373. Compressive strength exhibited an optimal peak of 24.1 MPa at a 12.5% RHA concentration, supported by impact energy absorption (3.29 Joules) without visible damage. The study reveals an optimal mix design of 12.2% RHA and 36.6% sand, demonstrating that RHA serves as an effective secondary reinforcement up to a critical threshold before binder starvation occurs. This research establishes a technical framework for circular economy practices in Tanzania, contributing to a high-performance, low-cost alternative to traditional cladding materials.