LAUSR

Abstract As known, Class F fly ash-based geopolymer system needs heat curing to obtain good properties. The heat curing of this system hinders its wide applications especially in the case of cast of situ. Thus, it is important to improve this system to be suitable for curing at room temperature. In this article, for the first time, the possibility of employing carbonation beet residue, resulting from the sugar beet industry as a by-product material, as an additive or accelerating agent to modify the properties of fly ash geopolymer cured at room temperature was studied. For this purpose, fly ash was partially replaced with carbonation beet residue at ratios in the range of 0–50%, by weight, with an interval of 5%. The specimens were cured at room temperature. The workability and setting time as well as compressive strength up to 90 days were determined. Different advanced devices such as X-ray diffraction, thermogravimetric and scanning electron microscopy were used to analyze the results. The obtained results showed that the incorporation of carbonation beet residue in the binder decreased the workability and setting time, whilst the compressive strength, especially at an early age, was improved. The optimum ratios of carbonation beet residue that gave good strength and a reasonable rate of setting were 10–25%. Higher ratios could show an unwanted rate of setting.