Mechanical properties of ultra-high strength cement-based materials (UHSC) incorporating metal powders and steel fibers. (7th February 2022)

• Record Type: Journal Article
• Authors: Yang, Kai; Tang, Zhuo; Cheng, Zhiqing; Zhao, Hong; Feng, Ruiping; Long, Guangcheng
• Is Part Of: Construction & building materials. Volume 318(2022)
• Publication Date: 2022-02-07
• Subjects: UHSC -- Micron-sized metal powders -- Steel fibers -- Mechanical properties -- Microscopic analysis; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2021.125926
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: The effects of metal powders on the mechanical properties of UHSC with steel fibers are studied. Hydration degree, pore structure characteristics, and micro interface morphology of UHSC are also investigated. A statistical damage constitutive model can reasonably describe the compressive stress-strain behavior of UHSC. The mechanical properties and microstructure of UHSC are improved by adding metal powders. Abstract: In this work, the mechanical properties of ultra-high strength cement-based materials (UHSC) incorporating metal powders and steel fibers under steam curing and autoclave curing were studied, with the special attention devoted to the flexural load-deflection response and compressive stress-strain behavior. Additionally, the hydration degree, pore structure characteristics and micro interface morphology were investigated to provide a thorough insight into the enhancement mechanism of metal powders and steel fibers on UHSC. The results show that the incorporation of Fe and Cu powders could enhance the flexural performance of UHSC, including the increased flexural strength and energy absorption capacity. Under uniaxial compression, improved peak stress, secant modulus, and energy absorption capacity of UHSC could be observed after the addition of Fe powders, but this improvement was negligible after the addition of Cu powders. Moreover, the statistical damage constitutive model based on strain equivalence hypothesis and improved statistical damage theory could reasonably describe the stress-strain behavior of UHSC under uniaxial compression. Furthermore, incorporating Fe and Cu powders could ameliorate the pore structure of UHSC, in which the harmful pores was converted into less harmful pores. Micro-interface morphology demonstrated that metal powders were closely bonded with cement paste, and no cracks or micro pores could be detected around the interface.