Technical Description:
• 40'-6" span x 42' wide Big R Bridge
® Rolled Girder
• 1,680 sf of ArmorFlex
® Class 45 Mats
• 490 units of 24-in. A-Jacks
®
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When the existing bridge on Gann Road over Cooper Lake Creek needed to be replaced, the project's engineer, Croy Engineering, required an option that would not raise the current elevation of the roadway. Products were also needed to address the scour issue occurring around the abutments of the existing structure.
After considering the options, Croy Engineering decided that a 40'-6" span x 42' wide Big R Bridge® Rolled Girder, along with 1,680 sf of ArmorFlex® Class 45 Mats and 490 units of 24-in. A-Jacks® to control the scour, would be the best solution. Croy was impressed that Contech Engineered Solutions could provide not only turnkey solutions for both the bridge and scour control systems, but also a quick installation and cost savings over other alternatives.
The Big R superstructure was designed by the manufacturer and prefabricated in a controlled environment in our Advanced Major Bridge-certified facility and offered precise tolerances, superior welding and continuous quality control versus location-built bridges. Most importantly, it was able to meet the needs of the site. The scour issue was controlled with a combination of two products: ArmorFlex, a flexible, interlocking matrix of cellular concrete blocks of uniform size, shape, and weight and A-Jacks, concrete armor units designed to interlock into a flexible, highly permeable matrix which dissipate energy and resist the erosive forces of flowing water.
Once the project was underway, extensive rain and flooding in the area challenged the installation timeline. Normally, working against the constant water flow would cause a delay, but because ArmorFlex and A-Jacks can be installed under water, the project's contractor, Baldwin Paving Company, Inc. was able to install the product in a timely manner even before the creek bed was completely dry. The Big R and ArmorFlex products were installed via crane, while the A-Jacks were placed by hand.
In the end, the three products were the perfect solution for the site, and Croy Engineering and the project's owner, the City of Smyrna, were satisfied with the outcome.
Funding for the project was provided by the 2016 Special Purpose Local Option Sales Tax.
Technical Description:
• 40'-6" span x 42' wide Big R Bridge
® Rolled Girder
• 1,680 sf of ArmorFlex
® Class 45 Mats
• 490 units of 24-in. A-Jacks
®
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