Evaluation and Comparative Analysis of Carbon-Negative Concrete Applications for Sustainable Infrastructure toward Net Zero 2050 in Vietnam

Abstract

The urgent demand to reduce carbon emissions from the cement and concrete industry has motivated the development of carbon-negative technologies. This study provides a comprehensive assessment of potential solutions for Vietnam’s infrastructure, focusing on two key applications: precast revetment blocks for coastal dikes and lightweight foam concrete for highway embankments. For precast blocks subjected to 2-hour CO₂ curing, an average uptake of 70 kg CO₂/m³ was recorded, with net sequestration of 62.6 kg CO₂/m³ after subtracting curing-related emissions. At the project scale of 1,000 m³, this corresponds to approximately 62-65 tons of CO₂ permanently stored. For CO₂-foam concrete, the average uptake reached 87 kg CO₂/m³, equivalent to 87 tons per 1,000 m³. Incorporating nano-silica or nano-CaCO₃ increased compressive strength by 30-35% and enhanced CO₂ fixation by 5-10%, enabling a reduction of 5-8% in cement content while maintaining required design strength. When compared to baseline C30 concrete (~295 kg CO₂/m³), these results highlight the potential to achieve net-negative emissions. The findings confirm that the deployment of carbon-negative concrete in Vietnam’s coastal and highway infrastructure could significantly contribute to the Net Zero 2050 target while providing durability and mechanical performance benefits.