Biopolymers as Bitumen Additives: A Systematic Quantitative Literature Review

Abstract

As sustainability gains importance, the search for eco-friendly alternatives to petroleum-based additives in bitumen modification has intensified. Biopolymers have been of great interest due to their positive impact on bitumen performance. This review analyzes studies on biopolymer-modified bitumen using the systematic quantitative literature review (SQLR) method. An article pool was prepared based onspecific criteria, and the test results of the articles were quantified and compared. Biopolymers were categorised into five main groups according to their frequency of use in bitumen modification: lignin and derivatives, natural rubber and derivatives, natural oil-based polymers, bio-based polyurethanes and others. The physical, rheological, and chemical properties of the biopolymer-modified bitumen were analyzed, as well as the results of mechanical tests on asphalt mixtures prepared with the relevant bitumens. Findings reveal that the effects of biopolymers vary by type, highlighting common trends, controversies, and research gaps in the literature.