Development Trends and Applications of Environmentally Friendly Building Materials

Abstract

The construction industry is a major contributor to global CO₂ emissions, primarily due to the production of Ordinary Portland Cement (OPC) and the extensive use of virgin aggregates. This study synthesizes recent progress on environmentally friendly building materials, focusing on three main alternatives: low-carbon cements, recycled aggregate concrete (RAC), and geopolymers. Harmonized metrics—CO₂ emissions per unit volume (kg CO₂-eq/m³) and emissions per unit strength (kg CO₂-eq/MPa)—are applied to compare these materials in terms of embodied carbon, compressive strength, and durability. Findings indicate that blended cements can achieve 30–60% CO₂ reduction while maintaining mechanical and durability performance comparable to OPC. RAC offers modest reductions (10–20%) but is constrained by strength and durability limitations, restricting its structural applications. Geopolymers show the greatest theoretical emission reduction (30–70%), though their performance varies widely and adoption is hindered by gaps in standardization. Overall, blended cements appear to be the most practical short-term solution, while geopolymers hold significant potential for future development with further research and codification.