Comparative life cycle assessment of chip seal preventive maintenance techniques: Cost and environmental implications

This study presents a comparative life cycle assessment and lifecycle cost analysis of seven chip-seal preventive maintenance treatments (Single, Double, and Triple chip seals; Scrub seal; Cape seal; Fiber-modified chip seal; and Rubberized chip seal) using a cradle-to-construction system boundary. Environmental impacts were quantified with SimaPro v9 (Ecoinvent) using the ReCiPe 2016 Endpoint (H) method for a functional unit of 1 m² of treated pavement and for the economic analysis, documented U.S. project costs and the Iranian price list were used and annualized with a 10 % discount rate. Results indicate that, under a cradle-to-construction boundary, Single Chip Seal and Scrub Seal have the lowest total normalized costs (1.88 and 2.6 USD/ m 2 ), while Rubberized and Triple Chip Seals show the highest total costs (7.06 and 6.28 USD/ m 2 ). When costs are annualized by service life, Single chip seal and Scrub seal remain the least costly (0.5 and 0.69 USD/ m 2 ), whereas Fiber chip seal, Cape seal and Triple chip seal are the most expensive ones (1.03, 1.05, and 1.05, respectively). From an environmental standpoint, Scrub Seal has the lowest total GHG emissions (≈1545 g CO₂e) and the lowest weighted endpoint scores across Human Health, Ecosystems and Resources, whereas Cape Seal and Triple Chip Seal are the worst performers (Cape seal total GHG ≈ 5301 g CO₂e; Triple chip seal frequently attains the maximum normalized score across midpoint categories). However, when these values normalized per service year, Rubberized Chip Seal yields one of the lowest annual GHG burdens (≈177.5 g CO₂e/year), illustrating the trade-off between higher upfront material and installation impacts and longer service life. Monte Carlo uncertainty analysis (1000 runs, 95 % CI) confirms that the relative ranking of alternatives is robust. The results highlight clear cost–environment tradeoffs and the importance of life-span weighting in selecting preservation strategies.