Date of Award
Spring 2017
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Civil Engineering
First Advisor
Wan, Baolin
Second Advisor
Foley, Christopher
Third Advisor
Heinrich, Stephen
Abstract
Surface preparation affects the bond behavior between Fiber Reinforcing Polymer (FRP) composite material and concrete. In this research, a special type of surface preparation known as grooving, which involves cutting transverse grooves, is conducted on concrete blocks (specimens) that are categorized as either Unfilled (U) or Filled (F). This idea is to ascertain how the grooves affect the strength of FRP-bonded-concrete specimen. These two categories are then benchmarked to control (C) specimens which do not have grooves on them. Category U specimens only have the epoxy applied on the concrete surface while category F specimens have epoxy applied on both the surface and in the grooves. To execute the test, single shear pull out test is conducted under which all the specimens are tested. Results from the test reveal that F specimens are 77% stronger than C specimens. This finding points to the fact that filled specimens possess extra strength due to the presence of epoxy in the grooves, which provide additional contact area and anchorage for the FRP. On the other hand, U specimens have similar strength as C specimens. Using single shear pull out test, the specimen under the test is designed such that a 25-mm pre-crack condition exist from the front edge of the concrete specimen. This crack mimics the initial debonding and helps to avoid stress concentration at the edge of concrete specimen. Tensile load is then applied on the FRP until failure, and the load, deflection, and strain data recorded using Minnesota Testing System (MTS) and National Instrument (NI) system. Physical appearances of the specimens after failure are observed, which show that failure occurs along the bond length, i.e. debonding failure. A wedge-shaped concrete chunk that breaks at the loading end of the specimen is also observed in most of specimens. Finally, numerical analysis is performed in order to compare results to experimental results. The analysis employs 3D Finite Element Modeling (FEM) in which all the three categories of the specimens are analyzed. Results from the FEM successfully simulates cracking patterns observed from the experimental tests.