Environmentally benign production of one-part alkali-activated slag with calcined oyster shell as an activator. (10th October 2020)

• Record Type: Journal Article
• Authors: Yang, Beomjoo; Jang, Jeong Gook
• Is Part Of: Construction & building materials. Volume 257(2020)
• Publication Date: 2020-10-10
• Subjects: One-part alkali activated-materials -- Alkali-activated slag -- Activator -- Shell waste -- Microstructure; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2020.119552
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: Oyster shell waste was calcined to produce an environmentally friendly and economical solid activator. Production of one-part alkali-activated slag with calcined oyster shell was extensively studied. Improved mechanical properties and microstructural characteristics were observed. Calcined oyster shell powder at excessive dosages induced a negative effect. Abstract: This study focuses on an environmental friendly, non-corrosive and non-viscous activator during the production of one-part alkali-activated slag using calcined oyster shell (COS) powder. Test results demonstrate improved mechanical and microstructural characteristics for specimens prepared with COS powder as an activator. The highest increment in the strengths was revealed with a 5% COS addition due to the resulting enhanced pore refinement, whereas an excessive dose resulted in a delayed rate of C-S-H formation and a significant amount of large capillary pores, thus decreasing the strength. The mineralogical and microstructural properties of the paste were also analyzed, and these findings revealed that COS powder is suitable for use as an activator to produce one-part alkali-activated materials.