Life cycle cost analysis of flexible pavements reinforced with geo-synthetics : a case study of new construction or repair overlays in Thailand’s roads

Abstract

This study investigates the economic viability and cost-effectiveness of the construction or repair of flexible pavements reinforced with geosynthetics in Thailand. The analysis was conducted on the road construction project under Muang District, Uttaradit province authority in Thailand, by adopting the life cycle cost analysis (LCCA) considering the agency, user, and environmental costs for the selected road segment. The study evaluated the economic analysis of the National Primary Road with and without geosynthetic materials by focusing on theoretical analysis and life cycle cost analysis considering the Thailand Highway Department's costs. Two types of geosynthetics were considered in this study, Polyfelt PGM-G 100/100 Geotextile paving fabric with a unit area of 430 g/m2 and Miragrid GX100/100 geogrid made from high tenacity polyester with a unit area of 335 g/m2 . The results revealed that using geosynthetics can extend the road maintenance cycle as much as the material's life, making the road maintenance cycle cost about 36.67% less than conventional pavement. Geosynthetic materials, particularly nonwoven geotextiles, demonstrated lower embodied carbon values (2.35 CO2e/ton) than geogrids (2.36 - 2.97 CO2e/ton). Combining Polyfelt PGM-G 100/100 geotextile with on-site pavement production resulted in lower total CO2 emissions (70,888 kg CO2 eq) than traditional flexible pavement. Hence, the utilization of geosynthetic materials can lead to more sustainable and economical approaches in road pavement construction in Southeast Asia where similar approaches can be adopted.