Assessing the Suitability of Using Pet Fiber and Binary Blended Binder for Enhancing the Performance of Earth Bricks

This study investigates the effect of incorporating PET (Polyethylene Terephthalate) fiber and a binary blended binder in the production of stabilized earth bricks, assessing their suitability as building materials. The research aims to evaluate the physical and chemical properties of rice husk ash, analyze the mechanical properties of termite mould earth bricks, and examine their thermal and microstructural characteristics. The methodology involved sourcing and processing termite mould and rice husk ash, from Ede Osun state, and locally obtained plastic bottles, which were shredded for incorporation. The sample were (100 x 100 x 50)and ( 200x100x50) for flexural test, sun dried. Various tests were conducted following ASTM and BS standards, including compressive strength, water absorption and thermal conductivity. SEM analysis was employed to assess microstructural properties. Results showed that compressive strength varied with composition, where Sample D (45% TMS, 25% RHA) exhibited the highest strength at 7 and 14 days (9.13 MPa and 9.47 MPa, respectively), while Sample A (60% TMS, 10% RHA) achieved the best long-term strength (11.07 MPa) at 28 days. Water absorption tests indicated that lower RCA content resulted in better durability, while higher RHA content increased porosity and reduced stability. SEM analysis highlighted that sample with higher RHA and PET fibers formed a denser matrix with improved crack resistance, whereas sample with a higher proportion of rice ash exhibited a weaker, porous structure. Flexural strength results indicated that RHA content positively influenced compressive strength up to 10% but negatively impacted flexural strength beyond that threshold, as excess RHA interfered with binder hydration and weakened the material structure. The findings emphasize the importance of optimizing the mix ratio to enhance strength while maintaining durability. This study contributes to sustainable construction by promoting stabilized earth bricks with improved mechanical and microstructural properties, offering a viable alternative to conventional building materials