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Moisture damage and low-temperature cracking are common distresses experienced by road pavement. Different types of modifiers, such as fibers, can be used to improve the quality of asphalt pavements. In this paper, lignin and glass fiber were selected as additives to enhance the water- and low-temperature stability of the asphalt mixtures. The main objective of this study was to evaluate the composite effects of adding lignin fiber and glass fiber to a bituminous mix using experimental methods. The Marshall immersion, freeze–thaw splitting, and three-point bending tests were applied to evaluate the efficiency of lignin fiber (and/or) glass fiber modified asphalt mixes with regard to moisture damage and low temperature. Four kinds of asphalt mixtures, namely, the control asphalt mix (C), lignin fiber modified asphalt mix (L), glass fiber modified asphalt mix (G), and a composite of lignin fiber and glass fiber modified asphalt mix (LG) were evaluated. The experimental results showed that with the addition of 0.30% lignin fiber and 0.30% glass fiber the water stability, low-temperature stability, and quality of bituminous mix were improved significantly. With lignin fiber, the asphalt mixtures showed better resistance to thermal cracking, while glass fiber resulted in greater moisture susceptibility. The composite admixture was more effective than either lignin or glass fiber in modifying the asphalt performance. This clarifies the great beneficial effect of using the composite mixture in the asphalt mixtures industry.

Lignin and glass fiber were used as additives to improve the quality of road pavements and minimize moisture damage and cracking at low temperatures on asphalt pavement, according to a previous laboratory study. The aim of this paper is to make a significant contribution to the environmental assessment of the construction of road pavements using four types of asphalt mixtures based on the life cycle assessment (LCA) methodology according to the requirements of ISO 14040, considering the impact of raw material extraction, asphalt mixture manufacturing, transportation, and wearing surface construction. The results of the environmental assessment showed that all studied asphalt mixtures do not offer any improvement in all impact categories, and three modified asphalt mixtures have a slight negative effect in all impact categories. The composite mixture has the highest negative effect of the studied three modified asphalt mixtures in all categories except in the marine aquatic ecotoxicity potential category and freshwater aquatic ecotoxicity potential category, where the lignin modified asphalt mixture has the highest negative effect in these two categories but has the best environmental impacts on most of other impact categories. Furthermore, the negative effect caused by composite asphalt mixtures is minimal and thus can be used to improve the overall performance of asphalt pavement.