Experimental investigation on the effect of nano silica fume on physical properties and microstructural characteristics of lightweight cement slurry. (25th April 2022)

• Record Type: Journal Article
• Authors: Zheng, Shaojun; Liu, Tianle; Qu, Bo; Fang, Changliang; Li, Lixia; Feng, Yintao; Jiang, Guosheng; Yu, Yinfei
• Is Part Of: Construction & building materials. Volume 329(2022)
• Publication Date: 2022-04-25
• Subjects: Lightweight cement slurry -- Micro-computer tomography -- Microstructural -- Nano silica fume -- Physical properties; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2022.127172
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: A novel nano silica fume was studied with particle size distribution between silica fume and nano silica. A quantitative relationship between the water-to-cement ratio, solid volume fraction and the nano silica fume content was established. A reference for the application of nano silica fume in the field of cementation was given. Abstract: The aim of this study is to investigate the effect of nano silica fume (NSF) on the physical properties and microstructural characteristics of lightweight cement slurry (LWCS) with a high solid volume fraction (SVF) above 45%. The slurries were prepared with various contents of NSF (0%, 5%, 10%, 15%, 20%, 30%). A series of tests were conducted to determine the rheological properties, compressive strength, settlement stability and uniformity. The reaction products and microstructures were characterized through XRD, SEM, micro-CT. Furthermore, the properties of pores of hardened cement stone, such as the fractal dimension of pores, were also analyzed based on micro-CT to track the influence of nano silica fume on the specimens. The results revealed that the incorporation of NSF significantly improved the compressive strength and the microstructural of LWCS. The improvement in strength resulted from the pozzolanic effect, filling effect and nucleation effect of NSF. NSF consumes portlandite to form more calcium silicate hydrate, acts as a filler to fill the empty space, provides nucleation sites for cement hydration, and finally makes the internal structure of the LWCS denser. Moreover, the water-to-cement ratio (w/c) and the SVF of LWCS both have a linear correlation with the content of NSF in LWCS.