Coal-derived char as new sand replacement material in cement mortars: A comprehensive experimental study

Area of Science:

• Materials Science
• Civil Engineering
• Construction Materials

Background:

• Coal char, a product of coal pyrolysis, offers potential applications in building materials.
• Investigating coal char as a sustainable additive in cementitious materials is crucial for eco-friendly construction.

Purpose of the Study:

• To evaluate the efficacy of coal char as a partial sand replacement in cement mortar.
• To comprehensively assess the engineering properties of coal char-based cement mortar.
• To compare the performance of coal char with commercial biochar in masonry cement mortar.

Main Methods:

• Coal char was used to partially replace sand in cement mortar at varying proportions.
• Selected mortar properties were comprehensively evaluated, including mechanical, physical, and thermal characteristics.
• Comparative analysis with conventional mortar and biochar-modified mortar was conducted.

Main Results:

• Optimal sand replacement with coal char (5%) enhanced compressive strength by 17.55% and flexural strength by 17.57%.
• Thermal conductivity decreased by up to 20% compared to conventional mortar.
• Coal char-based mortar exhibited 44.39% greater compressive strength than biochar-based mortar.

Conclusions:

• Coal char demonstrates significant potential as a sustainable additive for improving cement mortar properties.
• The use of coal char can lead to enhanced mechanical performance and reduced thermal conductivity in construction materials.
• Coal char presents a superior alternative to biochar for enhancing masonry cement mortar properties.