Upcycling waste flavedo into a bio-admixture of set retarder and compressive strength enhancer for cement-based materials. (15th January 2022)

• Record Type: Journal Article
• Authors: Zhang, Liheng; Chen, Peiyuan; Xu, Yangcheng; Hu, Xiuping; Wang, Yonghui
• Is Part Of: Journal of cleaner production. Volume 332(2022)
• Publication Date: 2022-01-15
• Subjects: Bio-admixture -- Flavedo powder -- Retarder -- Compressive strength enhancer -- Cement-based materials; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2021.130060
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: In this study, we propose a new and clean route to upcycle waste flavedo into a novel bio-admixture for cement-based materials. The effects of waste flavedo on the hydration properities, compressive strength, and microstructure of cement-based materials were investigated by setting time, heat flow calorimetry, X-ray diffractometer, thermogravimetric-differential thermal analysis (TGA-DTG) and scanning electron microscopy (SEM). The experimental results confirmed that the flavedo powder simply prepared by drying and grinding procedures acted as both a set retarder and a compressive strength enhancer for cement-based materials. The addition of 0.5‰ flavedo powder improved the compressive strength of the mortars by 9.91%, 10.5%, and 5.91% at 3d, 7d and 28d, respectively. Both hydration impeding and accelerating effects were observed when flavedo powder was added as a bio-admixture. In particular, the addition of flavedo powder impeded the formation of ettringite; however, it accelerated the generation of Ca(OH)2 . Moreover, the flavedo powder helped to refine the sizes of the cement hydration products and facilitated the formation of finer particles. In summary, this study provides a new insight into the clean reuse flavedo powder into a local available and low-cost bio-admixture, and would be benefit for relieving the needs on fossil fuel industry of chemical admixtures. Highlights: Flavedo powder was prepared through a simply and cleaner route. The addition of flavedo powder prolonged the setting times and improved the compressive strength of cement-based materials. The addition of flavedo powder facilitated the formation of finer particles during cement hydration.