The purpose of the Dwight D. Eisenhower Transportation Fellowship Program is to stimulate interest among Minority Institutions of Higher Education (MIHE) students in conducting transportation-related research, pursue transportation-related degrees, to enter the transportation workforce.  The proposal of the project was to provide a summary of how the plan of study will impact and enhance the field of transportation [Quesada, FHWA Application Proposal 2013].

This project focuses on the design and improvement of deep beams.  A deep beam is a beam with a short shear span (see figure 1 in Appendix A).  This means that a deep beam has a low span-to-depth ratio.  According to the American Association of State Highway and Transportation Officials (AASHTO), deep beams must contain a minimum amount of reinforcement equivalent to 0.3% of the cross-sectional area in both the vertical and horizontal directions.  Researchers have shown that this quantity is not a strength requirement.  Rather, it is required to control cracking or, limit the maximum crack width to less than 0.016 inches under the application of service loads.   Steel fiber reinforcement is known to be highly effective at limiting crack widths in concrete [Quesada, FHWA Application Proposal 2013]. 
When considering the actual size of these members, the quantity of reinforcement necessary to meet the AASHTO minimum requirement is substantial and installation is labor intensive.  It is likely that the steel congestion and subsequent labor costs of these members can be reduced through the addition of steel fibers.  This would likely decrease the maximum crack widths of these structures; thereby increasing their serviceability performance. For this project, “serviceability performance” is quantified as the rate of growth of the width of the maximum diagonal crack.   

Previously, researchers have studied fiber reinforced deep beams; however, they have not specifically examined the correlation between the fiber percentage and the minimum amount of web, or conventional, reinforcement.  As such, there is a demand for deep beam research where the primary variable is the quantity of fibers provided in the concrete mixture.

“Serviceability performance” is quantified as the rate of growth of the width of the maximum diagonal crack.  According to the American Association of State Highway and Transportation Officials (AASHTO), deep beams must contain a minimum amount of reinforcement equivalent to 0.3% of the cross-sectional area in both the vertical and horizontal directions.  Researchers have shown that this quantity is not a strength requirement.  Rather, it is required to control cracking or, limit the maximum crack width to less than 0.016 inches under the application of service loads.   Steel fiber reinforcement is known to be highly effective at limiting crack widths in concrete. 
Deep beams designed in practice are commonly as thick as 3-10 feet. When considering the actual size of these members, the quantity of reinforcement necessary to meet the AASHTO minimum requirement is substantial and installation is labor intensive.  It is likely that the steel congestion and subsequent labor costs of these members can be reduced through the addition of steel fibers.  This would likely decrease the maximum crack widths of these structures.  As a result, their service life would be increased.  

The experimental work will include the testing of nine reduced-scale deep beam specimens.  Specimens will be approximately 12-inches wide and 18-inches deep and will be tested with a span-to-depth ratio of approximately 1.8.  Experimental variables will include the volumetric percentage of steel fibers and the percentage of transverse web reinforcement.  Table 1 presents an overview of the testing program. 

Table 1: Testing Program Overview