Gravity is the solution

Case Studies
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When Clermont County, Ohio, needed to repair the deteriorating Elmwood Road Bridge, finding a solution that allowed them to finish the bridge repair on schedule was a top priority.

The bridge’s deteriorating abutments were composed of crumbling concrete blocks and natural stone. Fortunately, the bridge deck was still in good condition so the county was able to set it aside to be reused.

Based on the requirements and schedule for the project, the county chose Redi-Rock retaining walls to create the new bridge abutments. The county had used Redi-Rock to create bridge abutments and restore a similar bridge in 2005, and that experience heavily influenced the decision to use Redi-Rock on the Elmwood Road Bridge.

“The quickest way to repair the bridge was to remove the beams and replace the abutments using Redi-Rock blocks, similar to what we did on the Gaynor Road Bridge,” explained Clermont County’s Bridge Engineer Todd Gadbury, P.E.

Massive, 1-ton Redi-Rock blocks are known for their ability to harness the power of gravity to build tall walls that often do not require reinforcement. The blocks stack like giant Legos, making them quick and easy to install using an excavator and a small crew. The county’s engineering office decided to use the new Redi-Rock Ledgestone texture, because they liked the aesthetics it added to the project.

“It looks good, and we’ve gotten a lot of compliments. It adds nice character to the bridge,” Gadbury said.

Redi-Rock’s new Ledgestone texture blocks are cast in molds taken from natural quarried stone. Even though each block has nearly 6 sq ft of exposed face, the Ledgestone texture makes individual blocks nearly indistinguishable in a finished wall.

Gadbury designed the abutments using Redi-Rock 41-in. blocks, which allowed the abutments to be built as gravity structures. The design called for a 4- x 4-ft reinforced footer for which the crew had to excavate down into bedrock and shale. The first course of blocks was at creek level.

Gadbury designed a reinforced concrete grade beam to be placed directly atop the Redi-Rock abutments to help distribute the load throughout the walls. Because the abutments did not require excavation for reinforcement, the county’s crews saved on installation time and costs.

The Redi-Rock blocks were manufactured off-site by local manufacturer Redi-Rock Structures of OKI, so the walls did not require provisions for heating and curing as cast-in-place would have, even though they were installed during the cold Ohio winter.

In total, the abutment walls stood 13.5 ft tall. Construction of the project began in October 2010 and was completed in December with several delays due to weather.

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