Sustainable Low-Carbon Cement: Performance Enhancement with Calcined Natural Pozzolans Through Compressive Strength,...

Area of Science:

• Materials Science
• Civil Engineering
• Environmental Science

Background:

• The global cement industry is a major contributor to CO2 emissions.
• There is a critical need for sustainable alternatives to Portland cement.
• Natural pozzolans present a promising avenue for low-carbon cement development.

Purpose of the Study:

• To evaluate the potential of calcined natural pozzolans in developing low-carbon cement.
• To investigate the effects of kaolinite and pyroclastic rock-derived pozzolans on cement paste properties.
• To demonstrate a pathway towards environmentally efficient cement formulations.

Main Methods:

• Systematic investigation of cement paste properties using calcined natural pozzolans.
• Advanced characterization techniques: X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy with Energy Dispersive X-ray spectroscopy (SEM-EDX), and gas adsorption porosimetry.
• Analysis of hydration kinetics, compressive strength, microstructure, and porosity.

Main Results:

• Calcined natural pozzolans enhance cement performance by accelerating hydration.
• Improved compressive strength and refined microstructure observed in pozzolan-modified cement pastes.
• Cement pastes with pyroclastic rock pozzolans showed a 35.2% increase in 28-day compressive strength compared to ordinary Portland cement.

Conclusions:

• Calcined natural pozzolans are technically feasible for creating low-carbon cement.
• These materials offer a strategic approach to improving cement performance and reducing environmental impact.
• The findings support the significant reduction of the construction industry's environmental footprint through sustainable cement alternatives.