Impact of Sintered Fly Ash Aggregate on Mechanical, Durability, and Thermal Performance of Concrete

This research paper presents a detailed investigation into the use of waste fly ash–based lightweight aggregate developed by a sintering process in concrete. These sintered fly ash (SF) aggregates are replaced with natural aggregates in range of 10%–40% in concrete production. The study evaluates varying levels of SF aggregate replacement impact concrete’s physical properties (density), mechanical properties (compressive, flexural, and tensile strengths, and modulus of elasticity), durability properties (volume of voids, permeability, and water absorption), and thermal conductivity. The findings revealed that incorporating SF aggregate into concrete significantly reduces its density and mechanical strengths while increasing porosity and permeability. The study results showed notable improvement in thermal performance of concrete using SF aggregates. Statistical analysis confirmed the significant impact of SF aggregate on the investigated concrete properties, underscoring the complex interplay between material composition and concrete performance. The study concludes that although SF aggregates present certain drawbacks in terms of strength and durability, their positive influence on thermal insulation and potential in creating permeable infrastructure offers a promising area for further exploration. This research contributes to the ongoing dialogue on sustainable construction materials, advocating for a balanced approach to utilizing industrial by-products in concrete production.