Micromechanical Behavior and Micromorphology of Single PVA Fiber Pullout

Abstract:

To evaluate the suitability of domestic polyvinyl alcohol (PVA) fiber for preparing high ductility cementitious composites (HDCC), single PVA fiber pullout tests were conducted. The tests were carried out with four matrices having a water-to-cement ratio of 0.25 or 0.30, and fly ash replacement level 60% or 80%. The micromechanical behavior of single PVA fiber pullout from the matrix was monitored using a fiber tensile testing machine. Micromorphology of the pulled fiber was subsequently investigated using scanning electron microscopy (SEM). The results indicated that the slip-hardening coefficient is greater than zero and that the fiber therefore meets the micromechanical requirements for preparing HDCC. The chemical bonding energy and frictional bond strength were determined to decrease with the increasing fly ash content and/or water-to--cement ratio. SEM images indicate a significant number hydration products attached to the fiber surface, associated with an increase friction force during fiber pullout. After the pullout test, a complete tunnel containing fiber fragments was observed in the matrix, indicative of matrix cutting.

• Periodical: Key Engineering Materials (Volume 768)
• Pages: 331-335
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.768.331
• Online since: April 2018
• Authors: Bo Chen*, Li Ping Guo, Ya Nan Yang, Zheng Kai Chen
• Keywords: Micromechanical Behavior, Micromorphology, Pullout Test, PVA Fiber, Single Fiber

References

[1] Z. Lin, T. Kanda, V. C. Li, On interface property characterization and performance of fiber- reinforced cementitious composites, Concrete Science and Engineering. 1 (1999) 173-184.

[2] C. Redon, V. C. Li, C. Wu, et al, Measuring and modifying interface properties of PVA fibers in ECC matrix, Journal of Materials in Civil Engineering, 13(6) (2001) 399-406.

DOI: 10.1061/(asce)0899-1561(2001)13:6(399)

[3] V. C. Li, C. Wu, S. Wang, et al, Interface tailoring for strain-hardening polyvinyl alcohol-engineered cementitious composite (PVA-ECC), ACI Materials Journal, 99(5) (2002) 463-472.

DOI: 10.14359/12325

[4] L.P. Guo, B. Chen, W. Sun, et al, Effect of expansive agent on mechanical properties and deformation behavior of high ductility cementitious composites, J. Chin. Ceram. Soc., 44 (2016) 1609-1613.

[5] C. Wu, Micromechanical tailoring of PVA-ECC for structural applications, PhD thesis, Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Mich., Jan., (2001).