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Virtual Learning

Cracking and Debonding of a Thin Fiber Reinforced Concrete Overlay

  • Dec 17, 2018 (10:00 - 11:00 am CT; 9:00 - 10:00 am MT)
    Virtual Learning (desktop or laptop access)


REGISTRATION DEADLINE: Wednesday, December 12, 2018

The above opportunity and more can be accessed by visiting the TLN Learning Management System (LMS).


Fiber reinforced concrete has been used in bonded resurfacing overlays and assumed to have improved performance, as well as cost-effective. The benefit of improved toughness by incorporating fibers has proven to reduce cracking, yet other deformation characteristics and the bond interaction to the underlying layer is unknown.

The following objectives of this study include:

  • Investigate the impact of incorporating fibers on the mechanical properties of the bond by means of a wedge splitting test and a shear-bonding test.
  • Investigate and characterize the effect of fiber on debonding behavior with experimental tests.
  • Develop a finite element model, which predicts effects of debonding through shear or lift-off.

Experimental tests found the tensile interfacial energy increased with fiber-reinforcement. Also, bond tests indicated that interfacial fracture occurred through the overlay mixture and was proportional to the number of fibers which intersected the fracture path near this interface. The finite element analysis verified that crack width, vertical lift off, and debonding length all decrease as the fracture energy across joint increases or as the interfacial tensile bond increases.

Through this project, a series of testing systems were designed and built at the University of Utah lab to evaluate shear and lift-off performance of two-layer pavement systems. These can be used by future university, DOT, and other contracted projects for research and quality control measurements. The finalized testing systems and any limitations of using them can be found in the report. The user element subroutine with the finite element modeling can be similarly reproduced for future projects to improve validation and characterization of alternative pavement layer systems without extensive experimental testing always needed.

The full report can be viewed or downloaded at MPC 17-319


Dr. Amanda Bordelon, PE, Ph.D., is an Assistant Professor at the University of Utah. She received her B.S., M.S. and Ph.D. degrees in Civil and Environmental Engineering from the University of Illinois at Urbana-Illinois in 2005, 2007 and 2011, respectively. She is actively involved in professional societies and committees including the American Concrete Institute, Transportation Research Board, and International Society for Concrete Pavements. Her main area of expertise is in fiber-reinforced concrete pavements. Research topics include: fiber-reinforced concrete, concrete pavement design, ultra-thin whitetopping (concrete overlay bonded to asphalt), fracture mechanics, and x-ray CT imaging.

Target Audience

Materials, design and research engineers will benefit by this learning opportunity.

NDSU Dept 2880P.O. Box 6050Fargo, ND 58108-6050