Case Study
| Title: | Black Creek Bridge Repair, East of Exit 3 on Rt. 490 |
| Purpose: | 1.4 cubic yard DOTLine Deck Repair |
| Location: | Churchville, NY |
| Date: | September 26, 2007 |
Procedure & Observations:
Badly cracked and spalled section of bridge deck which butts directly against the steel joint. A portion of the deck was previously repaired with cold patch (asphalt) until a more permanent repair could be completed.
Preparation:
After determining the size of repair that could be completed; based on the quantity of available DOTLine, the perimeter was saw-cut and the field removed with jackhammers. Once the concrete was removed approximately ¾” to 1” below the rebar the area was sandblasted and blown free of debris. The final repair area dimensions were approximately 9’4” X 8’ X 7” deep.
Installation:
Surface temperature at time of installation startup was 75°F, material temp was 76°F and water temp was 710F. The weather started out mostly sunny then turned partly cloudy with a chance of rain. A steadily increasing breeze developed as the installation progressed.
The bridge crew had two, 2-bag concrete mixers that they used for placement. Do to the size of the repair the mixers were to small to effectively deliver material in a timely manner. The installation required 84 bags of DOTLine and took 2 hours and 53 minutes to install. Placement time could have been significantly reduced if a larger mixer or mixers had been available. Additionally the finish on the repair would have been greatly improved with faster material delivery.
The DOTLine performed within specification for working and finishing time. Overall the NYS DOT personnel on site were impressed with the product. It was stated by one of the bridge crew that they would never have tackled a repair of this size with the product they are currently using.
Conclusion:
The DOTLine demonstrated superior working characteristics for an installation of this size. The Assistant Bridge Maintenance Engineer for the Region was pleased with the results and will monitor the repair through the winter. The primary lesson learned by everyone present was that matching the mixers to the size of the repair is critical for ease of placement.
