Mechanical performance of concrete made with sewage sludge ash: A review (Part Ⅰ)

Abstract

Sewage sludge is frequently stable and safe when used as construction materials since it bypasses several of the costly and energy-intensive phases of usage. This is supported by numerous studies, particularly when the proportion of sewage sludge is at ideal levels. The primary goal of this article is to demonstrate the use of sewage sludge in building and construction materials. Novel properties such as slump flow and setting time as well as strength properties such as compressive strength, tensile strength, flexural strength, elastic modulus, impact energy, and absorbed energy are the main aspects studied in this review (Part Ⅰ). Part II describes the physical and chemical properties, durability, and morphological structure of the sewage sludge ash. The findings in this review (Part Ⅰ) indicate that the flow of concrete decreased with the addition of sewage sludge ash due to its porous nature, but the strength properties improved with sewage sludge ash due to micro-filling voids and pozzolanic activity, which improved the binding properties of cement paste. However, optimum substitution is critical as a greater proportion decreased the strength due to a deficiency of flowability, which boosted compaction energy leading to more cavities. Different studies recommend different optimum doses. However, the typical range for the optimum dose of sewage sludge ash is 5–10% (by wt) of cement.

Keywords

• concrete
• sewage sludge ash
• compressive strength