Frequently Asked Questions
Q: How long does it take for the reinstated core to set using the Utilibond?
A: With ambient temperatures of 70° F, the core will set and gain sufficient strength to exceed AASHTO H-25 standards by five times (over 50,000 lbs) in 30 minutes after reinstatement, and the road can safely be opened to traffic.
Q: Can I reinstate the core when the ground is frozen?
A: Not without some form of external heat source that will take the frost out of the core and the ground. Utilibond is a water-based cementitious product that will not bond or gain strength at freezing temperatures below 32º F or 0º C. The optimum working temperature is around 70º F or more that allows the Utilibond to set up and create a bond of sufficient strength to reopen the road within 30 minutes. As the temperature decreases, the time to set and gain strength will increase. At around 50º F it will take about 45 minutes to one hour to gain strength. At 40ºF it will take longer. It is not recommended to attempt to reinstate the core at temperatures below 40ºF without the aid of an external heat source.
Q: Can you recommend some sort of external heat source to warm the cut core and the hole in the pavement?
A: Utilicor manufactures a core heater that when properly used can heat a frozen core and the surrounding pavement from below 32 degrees F to 70 degrees F in less than 15 minutes.
Q: Do I have to use the Utilicor coring equipment / process in order to use Utilibond for core reinstatements?
A: No. The Utilibond will work on any cored pavement consisting of asphalt, composite asphalt / concrete, or concrete sidewalks.
Q: Why does the Utilicor process include a centre pilot hole?
A: The 2 " diameter bi-cone central pilot bit, which is integral to the Utilicor coring process, acts as a concentric guide for the coring drum, centering and stabilizing it to ensure a fast and accurate cut. The pilot hole itself provides a convenient access for the core-lifter by which the core or coupon is removed from the pavement and by which it is repositioned back into the pavement during reinstatement after completion of the repair. The central pilot hole, when filled with Utilibond increases the bonding surface of a typical 12" deep 18" diameter core by almost 100 square inches, adding strength to the reinstatement process.
Q: How long does it take to core through the roadway, and how deep can you cut?
A: It depends on the composition of the pavement but the entire process, from set up to finished cut, typically takes less than 30 minutes. In the case of an asphalt/concrete composite road with 4 inches of asphalt on top of 6 inches concrete, the Utilicor Rotary Coring truck will cut the core in 10 to 15 minutes. The standard core drum or barrel is 24 inches deep and will accommodate a 22-inch core. A 36-inch drum can accommodate a 34-inch core.
Q: How many cuts can I expect to get out of each drum?
A: Depending on roadway thickness and composition, you should get 60 to 100 cuts out of each of our Pro II coring drums. Normally, each drum can be re-toothed two to three times.
Q: How is Utilibond packaged?
A: Utilibond is packaged in a double-walled, plastic-lined, waterproof bag holding 20 kgs. (44 lbs.) that is contained in a sealed 30-gallon polyethylene pail that can be used for mixing. For convenience Utilibond also comes in a Twin-Pack version consisting of two 10 kgs. (22 lbs.) bags in each pail. Not only does the pail simplify the mixing and reinstatement process but also it preserves the watertight integrity of the product and contributes to its long, two-year shelf life.
Q: How much Utilibond permanent Pavement Bonding Compound is needed to reinstate a core?
A: It depends on the diameter and the depth of the core. A typical 18-inch diameter core between 9 to 22 inches deep will need 20 kgs. or one pail of Utilibond. The same diameter core 4-8 inches deep will only need 10 kgs. of Utilibond, and that's why we offer the Twin Pack which include two 10 kgs. bags of Utilibond. A 12-inch diameter core less than 15 inches deep will only need 10 kgs. of Utilibond, and so on.
Q: How much does it cost to reinstate a core?
A: It depends on the size of the core. Typically the cost to reinstate a core is comparable to the cost of a temporary asphalt patch on a typical utility cut, with the exception that the Utilibond repair is permanent.
Q: What kind of backfill material do you recommend when reinstating the core?
A: That will depend on what the city/municipality/facility owner has stipulated. The reinstatement process with Utilibond will work regardless of what material is used. i.e. native fill, unshrinkable fill, engineered fill, etc. For a number of reasons, many municipalities prefer native fill, but regardless of what type of fill is used, standard compaction requirements should be followed.
Q: Do you have to seal the edges of the core after reinstatement?
A: No. If properly installed, Utilibond creates a waterproof bond that is impervious to water penetration and it will not squeeze out or be displaced by traffic like other forms of sealants.
Q: What are the advantages of a circular cut over a traditional 2 foot by 4 foot utility cut?
A: First of all a reinstated circular core is more aesthetically pleasing and is almost invisible, But beauty is more than skin deep. Because you are replacing the actual core that was removed from the road it exactly matches the composition and structure of the rest of the road surface and contributes to its load sharing characteristics. A cored hole is also considerably smaller. An 18 inch diameter core leaves a 1.75 sq. ft. footprint as compared with an 8 sq. ft. foot print of a convention 2 by 4 cut, -- and like in micro surgery - smaller is better. Finally, in a conventional rectangular utility cut, the stress from traffic loading tends to concentrate in the corners where it causes cracking that can allow surface water to penetrate down and erode the road base which contributes to more rapid deterioration of the road. With a circular cut there are no corners. No corners no cracks.