Owner
Allegheny County Department of Public Works
Pittsburgh, PA

Project Engineer/
Designer
MS Consultants, Inc.
Coraopolis, PA

Repair Contractor
Concrete Repair Specialists
Sharon Center, OH

Material Suppliers/
Manufacturers
The Euclid Chemical Company
Cleveland, OH

George L. Wilson
Pittsburgh, PA

Jacks Run Bridge in Pittsburgh, PA, is a 15-span, 770 ft (235 m) long concrete bridge built in 1924 as a vital transportation link for Pittsburgh. The structure consists of a 320 ft (98 m) ribbed open-spandrel concrete arch and 14 approach spans. Since 1924, the age of the structure and the harsh weather have taken their toll on the bridge. The Allegheny County Department of Public Works made the decision to repair the structure.

The restoration work involved removing and replacing approximately 4000 cubic feet (113 cubic meters) of deteriorated concrete. A working platform, man lifts, and scaffolding were all used on the project; the conditions varied from confined spaces to locations 140 ft (43 m) above the valley floor. The scope of work also included applying a cementitious waterproofing coating. Concrete removal methods included chipping hammers, sandblasting, and hydrodemolition. Once the deteriorated concrete was removed, reinforcing steel was sandblasted and coated with an anti-corrosive cementitious coating. Severely deter- iorated steel and wire mesh were replaced as needed. Several ICRI guidelines were consulted throughout the restoration project for selecting the proper concrete surface profile and the mechanical means to achieve the appro- priate profile, providing guidance on proper treatment of corroded reinforcing steel and determining which type of concrete repair materials to select for the various sizes of patches.

The Jacks Run Bridge restoration was completed on time and under budget. The thorough planning of all phases of the concrete repair process—from removal of unsound materials to surface preparation, application of a bonding agent, formwork, repair material installation, and waterproofing coating application—allowed the contractor to restore the durability of the concrete bridge for many years to come.