Rapid urbanization and the widespread use of impervious materials have intensified the urban heat island (UHI) effect, raising surface temperatures and energy demands. Conventional concrete pavements contribute significantly due to their high thermal conductivity and low reflectivity. This study systematically investigates the development of thermally efficient concrete paver blocks using sustainable alternative fine aggregates to mitigate heat accumulation while retaining a minimum compressive strength of 35–45 MPa (recommended for medium traffic). Unlike prior isolated studies, this research offers a comprehensive comparative analysis of three sand replacements—Vermiculite powder (12.5–50%), Perlite powder (20–80%), and Crushed Glass (7.5–30%)—in M30-grade concrete. Fresh and hardened properties were evaluated through slump, density, and compressive strength tests at 7, 14, and 28 days, while infrared thermography quantified surface temperature variations under controlled heat exposure. Results showed significant thermal improvements, with optimal mixes Vermiculite 25% (VC-25), Perlite 40% (PR-40), and Crushed Glass 15% (CG-15) reducing surface temperatures by 25.1 °C, 22.2 °C, and 18.2 °C, respectively, while maintaining compressive strengths of 47.8 MPa, 38.8 MPa, and ~58 MPa. VC-25 proved superior, achieving the lowest surface temperature (26.3 °C) and 48.8% lower heat absorption than conventional concrete. The study establishes optimal replacement thresholds balancing insulation and strength, supporting SDGs 11, 12, and 13 through climate-responsive, resource-efficient construction materials.

Increasing dependency of the construction industry on cement, one of the most emission-intensive commodities, leads to the necessity for consideration of sustainable materials and permanent CO2 sequestration methods. One such material that has the potential to sequester CO2 is calcium carbide residue, a waste material of the acetylene gas-producing industry, generated in abundance. Currently, the material is dumped in a nearby dump site, which harms the soil due to its high alkalinity. Another main problem faced by the industry is the energy-intensive carbonation curing chamber, which neutralizes the effect of CO2 uptake by such novel materials. Hence, this study focuses on the fabrication of a low-pressure (0.2 bar) CO2 curing chamber without additional temperature and humidity control, and utilizing calcium carbide residue as a partial replacement of cement (5- 20%) with CO2 curing. Two sets of each mix design containing nine cubes were prepared and exposed to different curing regimes (water curing and CO2 curing, respectively) and evaluated for compressive strength (7, 14, 28 days) and CO2 uptake (mass gain, thermogravimetric analysis, Steinour’s equation). Further microstructural studies, such as scanning electron microscopy with energy-dispersive X-ray spectroscopy, along with statistical analysis and cradle-to-gate life cycle assessment, were performed. The 15% replacement mix showed optimum results with 26% increase in compressive strength, 7% increase in CO2 uptake, and 17% and 9% lower global warming potential and cost, respectively. Results showed that using this method, sustainable concrete can be produced, thereby achieving the United Nations’ sustainable development goals 9, 11, 12, and 13.