John Hillman, P.E. (born April 20, 1963) is an American structural engineer who invented the hybrid composite beam (HCB) and founded the HC Bridge Company. In 2010, he was recognized with the Award of Excellence from Engineering News-Record.
Education and career
Born in North Dakota and raised in east Tennessee,[1] Hillman received a bachelor's degree from the University of Tennessee in 1986[2] and a master's degree in civil engineering (MSCE) from Virginia Tech in 1990.[3] Hillman has worked at several well-known bridge companies including Figg & Muller (see Eugene Figg), Jean Muller International (see Jean M. Muller), VSL, Teng & Associates in Chicago.[2] He is currently employed at Kiewit (see Kiewit Corporation) in Denver, Colorado.
Development and design of the hybrid composite beam
At one point in his career, Hillman worked on developing fiber reinforced polymer (FRP) bridges. This led to his idea of the hybrid composite beam: combining a concrete and steel tied arch structure within an FRP box. A $320,000 grant from the Transportation Research Board's Innovations Deserving Exploratory Analysis (IDEA) program paid for the first HCB's to be constructed.(insert ENR ref tag) These beams were installed on a railroad test track (the Federal Railroad Administration's Facility for Accelerated Service Testing (FAST) loop at the Transportation Technology Center near Pueblo, Colorado). There the beams successfully supported a heavily-loaded train.[1]
The hybrid composite beam is single structural element, a beam. It is constructed as a composite of three materials steel strands, concrete, and fiber reinforced polymer. The materials are arranged in a manner that the materials act as what would traditionally be separate structural elements. The concrete is in the shape of an arch and carries compressive load internal to the beam. The steel strands act as a tie for the arch and carry the tensile load internal to the beam. The FRP shell carries the shear and bending moment internal to the beam. This means that the beam acts structurally in a hybrid nature, somewhere between a tied-arch and a beam.