The influence of wet ground fly ash on the performance of foamed concrete. (18th October 2021)

• Record Type: Journal Article
• Authors: Li, Guangyan; Tan, Hongbo; He, Xingyang; Zhang, Junjie; Deng, Xiufeng; Zheng, Zhengqi; Guo, Yanfei
• Is Part Of: Construction & building materials. Volume 304(2021)
• Publication Date: 2021-10-18
• Subjects: Foamed concrete -- Fly ash -- Lightweight -- High-strength -- Pore structure; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2021.124676
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: WGFA with D50 = 1.539 μm showed high pozzolanic reactivity and filling performance. The foamed concrete with WGFA showed a higher ratio of strength and density. The addition of WGFA was beneficial for the pore structure in foamed concrete. Abstract: In this study, fly ash was processed by the wet grinding process (i.e. WGFA), and the ions dissolution of wet ground fly ash was examined. Then, Portland cement-wet grinded fly ash foamed concrete was designed, and the effect of wet ground fly ash on the basic performance of the foamed concrete was investigated, including the wet/dry density and compressive strength. The hydration mechanism was revealed by XRD, TGA, and SEM, and the pore structure was characterized by micro-CT. Results showed that the foamed concrete with wet ground fly ash replacing cement showed a better performance than that without, ascribing wet ground fly ash with high activity, as well as excellent filling and particle grading effect. At 28 d age, the compressive strength of F40 (the substitution of WGFA was 40%) was 6.85 MPa, with an increase by 59% than F0 (the substitution of WGFA was 0%); and the (s/ρ) ratio of F40 was 10.23 Pa/(kg/m 3 ), with a 74% increase than F0 at 28 d age. In addition, wet grinded fly ash was conducive to optimize the pore structure (distribution, shape, and size), thereby further improving the compressive strength. This research provided a new approach for improving the properties of foamed concrete.