Preparation of a novel foamed concrete modified with carbon
fiber and graphite: Mechanical, electro-magnetic and microstructural
characteristics based on X-CT
Qin-chuan Tu1,2, Qing-hui Xia1, Yao
Lu1, Ying-hua Bai1,2*
1. School of Civil Engineering, Architecture and
Environment, Hubei University of Technology, Wuhan, 430068, China
2.Key Laboratory of Intelligent Health Perception and
Ecological Restoration of Rivers and Lakes, Ministry of Education, Hubei
University of Technology, Wuhan, 430068, China
Abstract: In this paper, foam concrete is modified using
graphite and carbon fiber as absorbents. The mechanical properties of
the foam concrete are analysed in conjunction with hydration products,
pore size distribution based on SEM test and XCT test. Further, the
resistivity, complex permittivity and complex permeability are tested.
The results demonstrate that carbon fiber enhance the proportion of
pores with diameters less than 200µm in foam concrete, thereby
substantially enhancing its flexural strength. Besides, adding graphite
offsets the initial retardation of sulfoaluminate cement hydration
induced by carbon fibers, which increases the average pore size of
carbon fiber-reinforced foam concrete, reducing the compressive
strength. The addition of carbon fibers at a concentration of 0.6wt.%
achieves the percolation threshold, akin to scenarios with singular
fiber incorporation. Exceeding 2wt% graphite content results in
negligible influence on the conductivity of the carbon fiber-reinforced
foam concrete. The synergistic integration of graphite and carbon fibers
significantly enhances the electromagnetic wave absorption performance
of the composite. At a thickness of 6 mm, the material exhibits an
effective bandwidth where the reflection loss is less than -10 dB,
extending up to 2.5 GHz, which constitutes 52.08% of the tested
frequency spectrum.
Keywords: carbon fiber(D); X-CT(B); magnetic property(C)