A review of innovative approaches to enhance bitumen properties for sustainable and climate resilient road infrastructure in Bangladesh

Abstract The durability and performance of bituminous pavements in Bangladesh are increasingly challenged by heavy traffic loading and climate-induced distresses. Although a wide range of studies has investigated bitumen modification using polymers, waste materials, mineral fillers, and bio-based additives, the resulting knowledge remains fragmented and difficult to translate into regional practice. This study presents a systematic and thematic review of peer-reviewed literature on bitumen modification strategies relevant to tropical and subtropical pavement conditions. The reviewed literature indicates performance improvements of varying magnitude under controlled study conditions, with plastic- and rubber-modified binders generally associated with enhanced rutting and fatigue resistance, while mineral and bio-based modifiers are reported to offer complementary benefits related to moisture resistance and sustainability. The review highlights variations in dosage–performance relationships across modifier types and explains them through comparative thematic interpretation. By interpreting variations in rheological behavior, binder–modifier interaction, and testing conditions, the study clarifies the mechanisms underlying inconsistent performance outcomes. A structured modifier suitability framework is also developed by integrating climate exposure, traffic demand, economic feasibility, and sustainability factors relevant to Bangladesh. The findings provide decision-oriented guidance for practitioners and policymakers in tropical developing countries seeking performance-based and climate-resilient bitumen modification strategies.