A comparative synthesis: How effective are different types of additives as bitumen modifiers for road construction practices in Kyrgyzstan?

The pivotal problem of this article revolves around the inefficiency of road durability in Kyrgyzstan. The study explores waste-based sustainable bitumen modifiers to address the challenges in Kyrgyzstan's road-construction techniques since it suffers from severe summer rutting and winter cracking. Based on a comparative analysis of analytical datasets from Central Asia, Indonesia, Bangladesh, Nigeria, Netherlands and Sweden to compare local climatic conditions with European standards. The results show that although adding 7.5% plastic waste improves stability in summer heat (+41°C), it reduces ductility to 14 cm to ensure cracking is stabilized. However, the use of a synergistic 5% sulfur and 2% HDPE modification is the most balanced, increasing the softening point to 51°C and lowering the fracture temperature to -30°C, while providing resistance to both rutting and thermal cracking. The results indicate that hybrid bitumen modifiers are more effective for Kyrgyzstan than just European standards with a single additive. Future work should assess the environmental safety, durability standards, practicality, sustainability and economically viable solutions.