Three hybrid composite beam (HCB) bridges were recently
constructed in Missouri, USA. HCB is an innovative idea that incorporates
traditional construction materials (steel and concrete) with fiber reinforced
polymer (FRP) composites in such a manner to optimize the performance of the
beam constituents. The HCB consists of self-consolidating concrete (SCC) poured
in classical arch shape and tied at the ends by conventional prestressing
strands. The concrete and steel are tucked inside durable fiberglass shell and
the voids are filled with polyiso foam. An integrated study was implemented on
the three bridges to investigate the HCB in-service behavior. The study
included quality control / quality assurance (QC/QA) testing program. As a part
of this research study, an innovative infrared (IR) thermal imaging approach
was developed to detect the voids in the concrete arch section during its
casting. The approach is found to be an ideal solution for QC/QA of the
concrete arch concrete placement. A series of load tests on the bridges
together with meticulous theoretical and numerical analyses were executed. The
first finite element analysis (FEA) for a HCB bridge superstructure was
accomplished. The analysis was used to provide better understanding for the girder
behavior and to emphasize the areas that need more examination. Based on the
FEA results the existing flexural design methodology and assumptions were
tested. The methodology was found unable to detect the maximum compressive
stress in the concrete arch, and the strain compatibility assumption was found
invalid. However, the experimental measurements along with the mathematical
calculations indicate that the HCB owns abundant nominal bending and shear
strength to withstand the expected loads during its lifetime. A modified
methodology that is based on the same assumptions as the existing one was
produced. The methodology was found to achieve significant enhancement in
predicting the stresses under the service loads. The durability of the HCB was
tested through subjecting the composite shell to different aging regimes. The
testing results indicate that the HCB possesses excellent durability in
relation to the expected weathering exposure in Missouri. Longer exposure
regimes are under implementation to assure these results.
Title: Field Evaluation of Hybrid-Composite Girder Bridges in Missouri
Published: August 2014
Report number: cmr15-002
Project number: TRyy1124
Author(s): John J. Myers, (Project Principal Investigator), Mohamed A. Aboelseoud, C. Renee Earley, Glenn Washer (Project Co-Principal Investigator), Justin Schmidt
Performing organization: Missouri University of Science and Technology and
University of Missouri-Columbia
