A comparative life cycle assessment (LCA), life cycle cost analysis (LCCA), mechanical and long-term leaching evaluation of road pavement structures containing multiple secondary materials

Abstract

Oil-Based Drill Cuttings (OBDC) are one of the hazardous wastes of the oil and gas industry. In this study, Reclaimed Asphalt Pavement (RAP), OBDC and Fly Ash (FA) geopolymer were used in Cold Central Plant Recycling (CCPR) mixtures. The dynamic modulus test was used to appraise the viscoelastic properties of CCPR mixtures. The Toxicity Characteristic Leaching Procedure (TCLP) test was also utilized to investigate the long-term contaminants leaching. In addition, a cradle-to-grave Life Cycle Assessment (LCA) and Life Cycle Cost Analysis (LCCA) were conducted to evaluate the potential environmental burdens and economic costs of pavement structures containing CCPR mixtures. Moreover, Multi-Criteria Decision-Making (MCDM) analysis using four different methods was performed to determine the optimal sample. The results revealed that the recycling of OBDC and RAP in stabilized CCPR mixtures with FA geopolymer can improve the viscoelastic properties and prevent the leaching of contaminants from these waste materials. Furthermore, recycling of the mentioned waste materials in CCPR mixtures has caused a significant reduction in global warming, acidification, eutrophication, smog, respiratory effects, Human toxicity, ecotoxicity, and cumulative energy demand up to 41%, 36.6%, 73%, 43%, 47%, 34%, 73%, and 13%, respectively. Additionally, using CCPR mixtures containing the OBCD, RAP, and FA geopolymer in the pavement structure has led to economic benefits of up to 31% compared to the conventional pavement system.