Authors: Ndongkeh Nelson Maineh, Edith Bate Etakah, Edna Buhnyuy Visiy, Mbeck Prosper Wanlo
Abstract: Plastic and diaper waste are major pollution problems worldwide. Approximately 72% of global plastic and diaper wastes end up in landfills, exacerbating environmental degradation, highlighting the urgent need for valorization strategies. This study investigated the potential use of Polyethylene Terephthalate (PET) plastics, diaper wastes and sand for the production of pavement blocks, with the goal of developing an environmentally sustainable method for repurposing these waste materials into valuable construction products. Four formulations of the paving blocks were produced and their mechanical and physical properties evaluated through various testing methods. For the four formulations, the plastic (binder) content was maintained at a constant 45% while the diaper (aggregate) content was being varied across formulations, replacing sand at percentages of 0%, 2.5%, 5% and 10% respectively. The results showed that the compressive strength of the blocks remained relatively constant across the first three formulations, with values of 10.23 MPa, 10.25 MPa, and 10.25 MPa, respectively, but dropped significantly in the fourth formulation (5.57 MPa). This indicated that a 10% replacement of sand by diapers in the fourth formulation is not advisable, as their compressive strength falls below the minimum of 8.5 MPa recommended by the SNI 03-0691-1996 standard. Moreover, the results also indicated that both flexural strength and abrasion resistance of the blocks declined as the diaper concentration increased, suggesting an optimal threshold concentration for incorporating waste diapers into the waste blocks. Also, the water absorption rate of the paving blocks increased with increasing diaper concentration with values of 0.34%, 0.34%, 0.92%, and 2.18%, respectively. However, all values were within the <20% limit for high quality blocks (ISS 1077-1970 Standard) suggesting that the blocks can withstand extreme environmental conditions, such as floods. The research demonstrates the potential to co-valorize waste plastics, diapers, and sand for the production of sustainable pavement blocks.
DOI: https://doi.org/10.5281/zenodo.15811965
