For a Durable Bridge Surface, Shot Blast
When it comes to dealing with bridge surface preparation, Shot Blast Inc. has enough experience to create superior surfaces that can endure for years. When a bridge is rebuilt, the top 2–5 inches of concrete must be removed through scarification. This results in micro-fracturing of the concrete surface, leaving a weak layer.
The only solution – shot blasting. We remove micro-fractured concrete by shooting high velocity steel balls at the surface, like we did on the Delaware Memorial Bridge. As a result, we eliminate micro-fractured concrete and contamination.
Each project has unique specifications, with varying grades (from coarse to very fine) and intensities of shot blasting. After this process, we then magnet-sweep the surface to remove excess steel and use high-powered blowers to prepare for resurfacing.
Job Specification and Surface Examination Checklist
- Determine if job specifications are in alignment with expectations of the project engineer.
- Create a detailed proposal that includes cleaning methods, concrete surface profile, and surface defect repair procedures.
- Check current surface for existing sealers, curing materials, grease, oil, efflorescence, traffic lines, tar, and dirt, all of which need to be removed.
Concrete Repair Guidelines
The International Concrete Repair Institute (ICRI) has created a guideline, “Selecting and Specifying Concrete Surface Preparation for Sealers, Coatings, and Polymer overlays.” It provides concrete surface profiles (CSP) that are used under the following conditions:
- Light Shot Blast (CSP 3): coating applications from 4–5 mils in thickness
- Medium Shot Blast (CSP 4 or 5): coating applications from 15–50 mils in thickness
- Medium-Heavy Shot Blast (CSP 5 or 6): coating applications from 40 mils to 1/8″ in thickness
- Heavy Shot Blast (CSP 6 or 7): topping applications from ¼” to ½”
- Extreme Shot Blast (CSP 8 or 9): concrete overlays greater than ½”
For more information about our bridge surface services, view our PDF brochure.