Sustainable use of plastic waste in plastic sand paver blocks: An experimental and modelling-based study

Plastic waste and cement manufacturing are detrimental to the environment, so this study employed plastic sand as paver blocks to promote a more sustainable future. This research prepared two kinds of paver blocks: plastic-based from plastic and sand and fibre-based from plastic, sand, and basalt fibres. An experimental and modelling-based study was employed. In the experiment, the samples were evaluated for compressive strength. The result showed that the 30% to 70% plastic-sand yields a superior effect of 18.06 MPa while 0.5% of basalt fibre showed 22.82 MPa, which enhances compressive strength by about 26.34%. Moreover, microstructural analysis conducted through scanning electron microscopy and energy dispersive X-ray spectroscopy, aimed to deepen insights into the interactions among plastic, sand, and basalt fibers in the composite material. In the modelling-based investigation, supervised machine learning techniques were employed: individual (gene expression programming, decision tree) and ensemble (random forest). The coefficient of determination (R2) results for GEP, DT, and RF were 0.95, 0.98, and 0.98, respectively. The statistical and k-fold cross-validation of the models was also done. It showed that RF performed better than the GEP and DT. Thus, eliminating cement from PSPB and replacing it with plastic waste will help the environment, save money, and reduce carbon dioxide emissions, all contributing to sustainable development. In addition, the construction industry can benefit from algorithms for modelling because they provide more efficient and cost-effective methods for evaluating the quality of materials.