Meso-mechanical interfacial behavior of elbow steel fiber reinforced concrete

Abstract

The strain distributions near the interface when the elbow steel fiber is pulled out from the half-mould concrete matrix are directly measured using a combined method of single fiber pull-out test and digital image correlation. Meanwhile, the real-time processes of the bonding, debonding and sliding at the interface are observed. The micro-mechanism of the strain localization in the failure process of interface when debonding occurs and the strengthening mechanism at the imbedded fiber are discussed. The experimental results show that the meso-scale strain localization gives rise to the localization of shear damage near the fiber interface. This strain localization characterized by the debonding process near the interface occurs, develops and moves gradually at an apparently regular interval. At the elbow part of the imbedded fiber, the peak value of the shearing stress occurs. But the primary debonding does not occur at this place because the strength of the shear damage is increased at the local area of the elbow part in the concrete, displaying an apparent reinforced effect at the end of the fiber.

Keywords

elbow fiber reinforced concrete / digital image correlation / debonding of the interface / strain localization

References

[1] Shen R. X., Wang Z. S., Cui Y. Z. Fiber Reinforced Concrete and Fiber Reinforced Cement[M], 2006 Beijing Chemical Industry Press

[2] W L Tian, C K Huang. Bond Mechanism for Deformed Fiber in Concrete[C]. Proc. 8 ^th National Meeting for Fiber Reinforced Cementitious Composites and Concrete, 2000

[3] Zeng B., Jin Z. S. Effect of Fibre on Steel Fibre Reinforced Concrete[J]. J. University of Sci. and Tech. Beijing, 1995, 17(5): 485-488.

[4] Yuan H. Q., Chen J. T., Zhu J. D. Experimental Study of Layered Steel Fiber-Polyacrylonitrile Fiber Reinforced Concrete on Mechanical Properties [J]. J. Wuhan University of Tech., 2003, 25(4): 31-34.

[5] Sayman O. Thermal-plastic Stress Analysis of Symmetric Aluminum Metal-matrix Composite Laminated Plates under Linearly Distributed Temperature[J]. J. Therm. Stress, 2003, 26: 1-12.

[6] Keiji O. Influence of Thermal History on Transverse Cracking in A Carbon Fiber Reinforced Epoxy Composite [J]. Adv. Compos. Mater., 2003, 11(3): 265-275.

[7] Kwadwo K., David J. R. Nanoindentation Method for Measuring Residual Stress in Brittle Materials[J]. J. Am. Ceram. Soc., 2003, 86(5): 811-816.

[8] Wang A. Q., Wan J. S., Gou W. X., . Study of Interfacial Stress of Single-Fiber Composite by Photo-Elastic Experiment[J]. Acta Mater. Compos. Sinica, 2003, 20(6): 147-150.

[9] Dong Z. Y., Li Q. B. Advances in Micromechanics for Fiber-reinforced Brittle Composites[J]. Adv. Mech., 2001, 31(3): 555-582.

[10] Chanvillard N. Modeling the Pullout of the Wire-drawn Steel Fibers[J]. Cem. Concr. Res., 1999, 29: 1 027-1 037.

[11] N Chanvillard. On the Modeling of the Pull out Behavior of Steel Fibers[C]. Proc. 1 ^st International Workshop High Performance Fiber Reinforced Cement Composite. 2002

[12] Alwan J. M., Naaman A. E. Effect of Mechanical Clamping on the Pullout Response of Hooked Steel Fibers Embedded in Cementitious Matrices[J]. Concr. Sci. Eng., 1999, 1: 15-25.

[13] Sujivorakul C., Waas A. M., Naaman A. E. Pullout Response of a Smooth Fiber with an End Anchorage [J]. J. Eng. Mater., 2000, 126(9): 986-993.

[14] Zhang G., Mou T. P., Zhang J. M. Displacement Measurement Using Image Analysis in Centrifuge Modeling of Slopes[J]. Chin. J. Geotech. Eng., 2007, 29(1): 94-97.