Life cycle analysis of paver block production using waste plastics: Comparative assessment with concrete paver blocks

Abstract

Recycling of plastic waste to replace cementitious products to some extent can be a better way to get rid of plastic waste and avoid the use of cement. But to make any innovation into a scale-up technology, a comparative study on environmental emissions is needed. The present study evaluates the environmental emissions from two plastic recycling methods for manufacturing paver blocks (PB) and compares these with the emissions of conventional concrete paver blocks (CCPB). Life cycle analysis (LCA) has been performed on three PB manufacturing processes (CCPB, Plastic as filler paver blocks (PFPB) and Plastic as binder paver blocks (PBPB)) considering the impacts from materials and energy interaction in each step and operation. The impacts obtained from the CML 2001 and TRACI methods have shown that the emissions from PFPB (GWP 21.4 kg CO2 eq.) and CCPB (GWP 16 kg CO2 eq.) are almost 2.2 and 1.6 times higher than PBPB (GWP 9.86 kg CO2 eq.). The LCA study shows that use of cement has major contribution (for instance >80% in GWP category) to overall emissions for PFPB and CCPB. The sensitivity analysis elucidates that transportation distance and truck payload for CCPB and PFPB processes and electricity consumption for PBPB, shift the impacts in greater magnitude (±3–10%) by ±20% variation in input parameter values. The LCA study concludes that the PB manufacturing by complete replacement of cement is more environment-friendly process than PFPB and CCPB. The use of electricity from solid biomass and hydropower can reduce the GWP by 77% and 83% respectively.