Top 10 Keyhole Uses For Smart Construction

February 2014, Vol. 69 No. 2

The cost of installing and maintaining underground utilities continues to increase.

Pavement restoration costs can be reduced by as much as 80 percent by employing new and safer construction techniques such as the keyhole coring and reinstatement process. In the past 15 years, more than 250,000 keyhole cores have been successfully cut and reinstated in the nation’s streets and sidewalks, saving North American utilities billions of dollars in pavement restoration costs.

Like microsurgery in the medical field, the keyhole technology process enables utility crews to safely and cost-effectively conduct main replacement activities, locate underground infrastructure and perform repair or maintenance work from the road surface through 18-inch or 24-inch diameter ‘keyholes’ cored through the pavement, thereby avoiding more costly, disruptive and inherently more dangerous excavation methods. The reinstated pavement cores result in a permanent, almost invisible, perfectly matching, waterproof pavement repair that can maintain the performance life of asphalt and concrete pavements and significantly reduce traffic delays and inconvenience to the public.

In addition to reducing cost and public inconvenience, keyhole technology is also an environmentally friendly process that eliminates the need for new paving materials and the disposal of old, by reusing the same materials that were originally used to build the roadway to restore it after the excavation. The coring and reinstatement process reduces the carbon footprint of utility cuts and pavement restorations to one-sixth of that generated by conventional means and avoids the consumption of millions of tons of asphalt paving materials and the disposal of millions of cubic feet of asphalt spoil every year in utility cut repairs.

Here’s a look at the top 10 applications for keyhole technology.

1. Daylighting for damage prevention
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Daylighting or potholing can be used everywhere but is most commonly found in advance of horizontal directional drilling work. These small access holes can be opened through both soft and hard surfaces to allow for visual confirmation of buried utilities in the bore line to reduce the chance of inadvertent hits to existing buried infrastructure. Not only does this process prevent damage, but a precisely cored and reinstated keyhole is better for the roadway, easier on the worker, causes less inconvenience to the public and saves thousands of dollars in paving restoration costs.