Applications & Innovations
Better Roads Staff
By Lauren Heartsill Dowdle
Whether it’s patching a hairline crack or completely rebuilding an area with a crater-sized pothole, repairing concrete roads early on can minimize future damage and the time required for the job.
The repairer’s success with the work depends not only on the quality of the patching work itself but also on his pre-patching assessment and choice of solution. Figuring out the cause of the pavement deterioration can help determine what type of repair is best suited for the project.
“Know what kind of repair you need to make and then follow through with it,” says Dale Harrington, senior principal engineer, Snyder and Associates/National Concrete Pavement Technology Center. “You can’t just jump into it.”
If a crack occurs while working on a current project, it may be easier for the crew to diagnose the problem by retracing their steps. Was there a sudden change in the temperature? Did it rain? Did they forget to cover the surface? Or, was there a change in materials, saw timing or subgrade with the cracked section? Volume changing, restraint, curling, warping, strength, stiffness, base condition and early loadings are also factors that can cause early stage cracking.
It’s possible for concrete to go 20 to 30 years without needing any renovation, so for existing pavement, the direct cause may be unknown – it could, for example, range from load-associated issues to long-term drying shrinkage. But no matter the reason, the road deterioration symptoms are universal. Once diagnosed, the repairer can set a plan of action.
In many jobs, the deterioration will require a combination of techniques to become a smooth, sturdy pavement. Knowing what signs to look for and how to best treat the area will help road contractors achieve the best long-term results. “The types of repairs range from slab stabilization to joint-crack resealing,” Harrington says. “If multiple repairs are required, the sequence of applications needs to be understood and followed.”
Let’s dicuss eight popular types of concrete repair.
1. Full-Depth Repair
For major distress pavement areas, full-depth repairs can provide quality performance for 10 to 15 years if crews use the right materials. These repairs normally consist of cast-in-place concrete that replaces the full depth of the existing slab, or at least a portion of a slab to the bottom of the concrete.
This technique can be used where utility cuts are needed in the roadway, to restore problem areas at airports or at deteriorated cracks and joints on highways.
One of the most common types, full-depth repairs are usually a full lane-width wide, say12 feet, and 4 to 6 feet long, says the American Concrete Pavement Association.
Key techniques for effective full-depth repairs include having adequate working room (a minimum of 6 feet longitudinally), a uniform/stable platform, full-depth perimeter saw cuts, a longitudinal strike-off and being prepared for changes. The success of this repair also depends on installing it at the proper time with the right design.
If the slab could disintegrate when lifting it, crews should remove the patch area with a backhoe, angle the lift pins, position the cables and keep the lift height to a minimum.
MORE FROM Applications & Innovations
- Sydney uses water curtains to alert drivers to stop (VIDEO)812 Views
- Obama signs memorandum to expedite infrastructure projects617 Views
- Florida’s Red Light Camera Game: G R E E N orange R E D320 Views
- Big four cellphone companies jointly launch anti-texting campaign267 Views
- Acceptance of connected vehicles depends on cost, LaHood says265 Views