Title:
Cyclic Damage to PVA Microfibre Embedded in Cementitious Matrix in Alternating Tension-Compression Regime
Author(s):
Ranjbarian, M.; Mechtcherine, V.
Publication:
Symposium Paper
Volume:
343
Issue:
Appears on pages(s):
321-329
Keywords:
SHCC, cement-based composites, PVA microfibre, fibre pull-out test, fatigue, cyclic tension-compression loading regime, cyclic damage
DOI:
Date:
10/1/2020
Abstract:
The structures subject to dynamic loading demand more ductile materials to prevent catastrophic failure. The results of investigations on strain-hardening cement-based composites (SHCCs) distinguished this group of materials – due to their highly ductile behaviour – as a suitable alternative for structures with high resistance against seismic, impact and cyclic loadings. While mechanical properties of SHCC are determined mostly by bridging
behaviour of dispersed fibres crossing cracks and properties of fibre-matrix interface, the dependency of these mechanisms on the loading regime is pronounced. Specifically, under cyclic loading, the number of cycles to failure decreases dramatically when SHCC is subject to alternating tension-compression regime. Degradation of fibres compressed between the crack faces and deterioration of their bridging capacity are responsible for such early failure and necessitate further investigations at the micro level. The article at hand presents the influence of loading history in cyclic tension-compression regime on the bridging capacity of the single PVA microfibre embedded in cementitious matrix. A novel double-sided single fibre pull-out setup is used for the experimental investigations. First the test setup, material composition and testing procedure are explained. Next, the results of double-sided pull-out
specimens, tested under monotonic and cyclic tension-compression regimes, are discussed. It is shown that the deterioration of fibre bridging capacity can be assessed by applying cyclic loading in post-cracking stage, followed by pulling the fibre out of the matrix. Possibility of a change in pull-out behaviour of PVA microfibre from “fibre rupture” to “fibre pullout”, also a change of behaviour in post debonding regime from “hardening” to “softening” are also
observed. Eventually, the results of microscopic analysis are presented and discussed, which show the specific phenomena responsible for changes in pull-out behaviour.
Related References:
Boshoff, W. P., Mechtcherine, V., & van Zijl, G. P. A. G. (2009a). Characterising the timedependant behaviour on the single fibre level of SHCC: Part 1: Mechanism of fibre pullout creep. Cement and Concrete Research, 39(9), 779–786. doi: 10.1016/j.cemconres.2009.06.007
Boshoff, W. P., Mechtcherine, V., & van Zijl, G. P. A. G. (2009b). Characterising the timedependant behaviour on the single fibre level of SHCC: Part 2: The rate effects on fibre pull-out tests. Cement and Concrete Research, 39(9), 787–797. doi: 10.1016/j.cemconres.2009.06.006
Fukuyama, H., & Suwada, H. (2003). Experimental Response of HPFRCC Dampers for Structural Control. Journal of Advanced Concrete Technology, 1(3), 317–326. doi: 10.3151/jact.1.317
Jun, P., & Mechtcherine, V. (2010). Behaviour of Strain-hardening Cement-based Composites (SHCC) under monotonic and cyclic tensile loading. Cement and Concrete Composites, 32(10), 810–818. doi: 10.1016/j.cemconcomp.2010.08.004
Katz, A., & Li, V. C. (1996). A special technique for determining the bond strength of microfibres in cement matrix by pullout test. Journal of Materials Science Letters, 15(20), 1821–1823. doi: 10.1007/BF00275353
Kesner, K., & Billington, S. L. (2004). Tension, Compression and Cyclic Testing of Engineered Cementitious Composite Materials. Technical Report, Cornell University, School of Civil and Environmental Engineering, Ithaca, New York 14853.
Mechtcherine, V., & Curosu, I. (2017). Mineral-Bonded Composites for Enhanced Structural Impact Safety - A New Research Training Group GRK 2250 of the German Research Society. Procedia Engineering, 210, 182–185. doi: 10.1016/j.proeng.2017.11.064
Müller, S., & Mechtcherine, V. (2017). Fatigue behaviour of strain-hardening cement-based composites (SHCC). Cement and Concrete Research, 92, 75–83. doi: 10.1016/j.cemconres.2016.11.003
Ranjbarian, M., & Mechtcherine, V. (2018). A novel test setup for the characterization of bridging behaviour of single microfibres embedded in a mineral-based matrix. Cement and Concrete Composites, 92, 92–101. doi: 10.1016/j.cemconcomp.2018.05.017
Yamamoto, S., Yano, Y., Kinoshita, K., Lim, S., & Shinya, K. (2018). Cyclic Loading Test on 0.2-Scale RC Column Models Repaired by Strain-Hardening Fiber-Reinforced Cement-Based Composites. In V. Mechtcherine, V. Slowik, & P. Kabele (Eds.), Strain-Hardening Cement-Based Composites (pp. 734–742). Dordrecht: Springer Netherlands.