Introduction As Viet Nam's economy continues to grow, the expansion of the country's road network is essential to support the increasing movement of goods and services. New roads strengthen connections among regions, facilitate domestic trade, and improve links with neighboring countries, contributing to economic growth and regional integration. However, expanding transport infrastructure also presents an environmental challenge. Conventional road construction using hot mix asphalt requires high production temperatures, resulting in high energy consumption and carbon dioxide emissions. As Viet Nam pursues its goal of achieving carbon neutrality by 2050, reducing the environmental footprint of road construction has become an important consideration alongside infrastructure development. To help address this challenge, the Korea Institute of Civil Engineering and Building Technology (KICT), a government-funded research institute in the Republic of Korea, is evaluating the application of warm mix asphalt technology in Viet Nam. By enabling asphalt to be produced and placed at lower temperatures than conventional methods, the technology aims to reduce carbon emissions while maintaining the structural performance required for the country's roads. Analysis Much of the energy consumed during conventional hot mix asphalt production comes from heating raw materials before they are mixed. This stage also accounts for much of the associated carbon dioxide emissions. By lowering the production temperature, both energy use and emissions can be reduced. Warm mix asphalt technology enables asphalt mixtures to be produced and placed at temperatures 20°C–30°C lower than those required for conventional hot mix asphalt. Based on a 2024 study, reducing production and construction temperatures lowered energy consumption by at least 15% and carbon dioxide emissions by at least 18%. While the environmental benefits of warm mix asphalt have already been demonstrated in many countries, its suitability for Viet Nam depends on whether it can deliver comparable structural performance under the country's traffic loads and hot, humid climate. The key question, however, was whether these environmental benefits could be achieved without sacrificing pavement performance under Viet Nam's local conditions. To answer this question, KICT, in cooperation with Yoonsung Industrial Development, the Government of Viet Nam, and local construction companies, constructed a pilot test section along a 150 m, one-lane stretch of National Highway 1 (KM 1,871+800 to KM 1,872+000). The pilot section was selected because it carries mixed traffic, including medium- and heavy-duty vehicles, and is continuously exposed to hot and humid conditions. The first half of the section was paved using conventional hot mix asphalt to serve as the control, while the second half used warm mix asphalt incorporating a diamine-based wax additive together with a polymer additive developed by Yoonsung Industrial Development. The additives lower production temperatures while improving pavement durability. The pilot was designed to evaluate both the environmental benefits and the engineering performance of the proposed asphalt mixture before considering its wider application. To determine whether the technology could perform under Viet Nam's conditions, the pilot was evaluated through laboratory testing and will continue to be assessed under actual traffic conditions. To assess the structural performance of both mixtures, asphalt samples collected during construction were used to prepare laboratory specimens for testing. The specimens were evaluated for resistance to common pavement distresses, including cracking and plastic deformation. The results showed that the warm mix asphalt outperformed the conventional mixture, with 10% greater resistance to cracking and 28% greater resistance to plastic deformation. Because Viet Nam's tropical monsoon climate exposes roads to prolonged moisture, both asphalt mixtures were also tested for moisture resistance. Laboratory specimens were tested before and after one day of water immersion to determine their retained strength. Although both mixtures exceeded the country's standard requiring a retained strength of at least 80%, the warm mix asphalt achieved a retained strength that was approximately 3% higher than the conventional hot mix asphalt. The pilot test section will continue to be monitored under actual traffic conditions. An on-site evaluation after one year of service will provide additional evidence on whether warm mix asphalt can deliver durable, lower-carbon pavement performance under Viet Nam's local conditions. Implications Balance sustainability with performance Introducing innovative technologies into public infrastructure requires more than improving environmental performance. New solutions must also demonstrate that they can meet the functional and durability requirements of existing technologies under local conditions. In Viet Nam, the pilot application of warm mix asphalt addresses the high energy consumption and carbon emissions associated with conventional hot mix asphalt while maintaining the structural performance expected of road pavements. The preliminary laboratory results indicate that warm mix asphalt is a promising lower-carbon alternative for Viet Nam's road sector. Consistent with the experience of countries such as Germany, the Republic of Korea, and the United States, the technology offers lower energy consumption and reduced carbon dioxide emissions compared with conventional hot mix asphalt. At the same time, the laboratory evaluation showed that the warm mix asphalt performed as well as, and in several measures better than, the conventional mixture in resisting cracking, plastic deformation, and moisture damage. The ongoing field evaluation will provide further evidence of its long-term performance under Viet Nam's traffic and environmental conditions. Validate technologies under local conditions While global experience provides confidence in emerging technologies, local validation remains essential before wider adoption. The pilot in Viet Nam demonstrates the importance of evaluating innovative solutions using locally available materials, local construction practices, and actual operating conditions to determine whether they can meet the country's specific infrastructure needs. Strengthen partnerships for technology adoption The collaboration among KICT, government agencies in Viet Nam, local construction companies, and industry partners provides a practical model for introducing new pavement technologies. By combining international research expertise with local implementation and industry participation, the project builds confidence in the technology while supporting knowledge transfer and future adoption. Support long-term adoption through localization If the pilot continues to demonstrate positive results, the wider adoption of warm mix asphalt could support Viet Nam's transition toward lower-carbon road construction while encouraging the development of local material specifications and construction standards. In the longer term, this foundation could also facilitate the adoption of other sustainable pavement technologies, including asphalt recycling and the use of waste materials as alternatives to conventional aggregates. More broadly, the pilot demonstrates how lower-carbon road technologies can be validated through local materials, strategic partnerships, and real-world operating conditions before wider adoption. This approach provides a practical pathway for introducing greener road construction practices in Viet Nam and may offer useful lessons for other developing countries pursuing more sustainable infrastructure. Resources Asian Develoment Bank. ADB. 2020. Climate Change Adjustments for Detailed Engineering Design of Roads: Experience from Viet Nam. Y. Liu et al. 2024. A Review of Sustainability in Hot Asphalt Production: Greenhouse gas Emissions and Energy Consumption. Applied Sciences, 14, 10246. Korea Institute of Civil Engineering and Building Technology website. Ask the Experts Byung-Sik Ohm Research Fellow, Department of Highway and Transportation Research, Korea Institute of Civil Engineering and Building Technology Byung-Sik Ohm has more than 20 years of experience contributing to local and international projects related to pavement design, monitoring, maintenance, and management systems. He earned his doctoral degree from Hanyang University. Carlo Elipse Postdoctoral Researcher, Department of Highway and Transportation Research, Korea Institute of Civil Engineering and Building Technology Carlo Elipse's research areas include pavement design and management systems, the development of innovative pavement materials, and the application of non-destructive testing methods for road evaluation. He holds a PhD in civil engineering from Sejong University. Korea Institute of Civil Engineering and Building Technology (KICT) The Korea Institute of Civil Engineering and Building Technology contributes to the development of the Korean construction industry, improves quality of life standards, furthers national economic growth, and improves social welfare. It promotes original technology in the fields of land, infrastructure, and construction. Leave your question or comment in the section below: View the discussion thread.