The Implementation of a Binary Blend of Waste Glass Powder and Coal Bottom Ash as a Partial Cement Replacement toward More Sustainable Mortar Production

Abstract

One way the sustainability and efficiency of concrete production can be improved is by incorporating waste by-products into the mix. This can help reduce the use of natural resources, such as river sand, and prevent the pollution of valuable land. Two specific examples of waste by-products that can be used in the concrete industry are waste glass powder and coal bottom ash. This study presents an experimental investigation that analyzes the influence of adding glass powder and waste bottom ash from 0% to 20% with a 5% interval to produce high-performance mortar for rheological, mechanical, and durability properties cured under different conditions (wet and dry) and temperatures (20 °C), and at several curative processes at 7 and 28 days. The water/cement ratio is a constant 0.35. According to the research findings, blending glass powder and coal bottom ash in the production of mortar results in a significant improvement in performance, particularly in terms compressive and flexural strength (3.4–20.8%) (1.7–20.3%), while employing a 10% WGP and 10% CBA binary blend provides a large increase in the flexural strength (10.6%). In the fire resistance test, 15% WGP and 5% CBA has the maximum bond strength at 200 °C (2.6%). In SEM pictures of WGP and CBA, it is found that the two materials have a low porosity compared to the control cement mortar. Furthermore, the study finds that 10% glass powder and 10% coal bottom ash combined with cement paste is the best percentage of waste by-products to use in the creation of high-performance mortar. This ratio was discovered to be the most successful in terms of increasing mechanical, rheological, and durability qualities.