Arya Ebrahimpour and Mustafa Mashal Receive Funding From Idaho Transportation Department

Drs. Arya Ebrahimpour and Mustafa Mashal of the Department of Civil and Environmental Engineering

have received funding from the Idaho Transportation Department (ITD) to determine suitability of a type

of high early strength concrete with polypropylene fibers as a cost-effective alternative to connect

precast bridge deck elements in Accelerated Bridge Construction (ABC). ABC methods are relatively new

in the U.S. and Idaho. ABC requires that the bridge precast concrete components be effectively

connected to one another in the field. To this end, there is currently a growing nationwide trend to use

Ultra High Performance Concrete (UHPC) for field connections. Although UHPC is an excellent material

with an extremely high compressive strength, it is a proprietary material with a cost of $8,000-$10,000

per cubic yard and its proper installation requires very rigorous preparation and quality control. High

early strength concrete with fibers can be batched in the ready-mix plant, brought to the field in the

mixing truck, and placed similar to a conventional concrete. The proposed alternative material has a

lower cost of $600-$700 per cubic yard. The estimated cost saving of the proposed material versus

UHPC or high strength mortar for one bridge project alone is approximately $100,000.

The project objectives are to: (1) obtain experimental data on the behavior of high early strength

concrete Class 50AF with polypropylene fibers for use as a closure pour material between the bridge

Deck Bulb-T girders, and (2) use the experimental results to create a finite element computer model of

the proposed closure pour connection detail. The computer model of the bridge deck connection detail

is anticipated to (1) be capable of assessing the deck connection strength under truck loading, and (2)

provide an indication of fatigue performance under repeated loading. At the conclusion of this project,

if the connection strength results are promising, the next proposed phase will include larger scale

laboratory testing and/or field measurements.