Con-Cor Core Drilling

With over four decades of concrete cutting experience, we have encountered numerous concrete cutting scenarios. Con-Cor-Co has vast experience and a skilled workforce to work with any of your core drilling needs. We can drill large or small diameters, angled or deep drilling concrete coring.

Con-Cor is readily equipped to handle any service core drilling no matter the size or quantity. As an added bonus, Con-Cor has skilled employees who have worked in the industry many years. Con-Cor is always ready to satisfy your scheduling needs in any situation.

Our expertise at Con-Cor is reflected in our track record of excellence. Con-Cor has performed work on the following major projects around Milwaukee, Wisconsin, and beyond:

  • Miller Park
  • Marquette Interchange
  • Mitchell Field
  • MMSD
  • Racine WTP
  • Hanson’s Landing
  • Froedert Hospital
  • Camp Randall
  • O’Hare Field
Con-Cor Core DrillingCore Drilling Froedert Eye Clinic, Milwaukee, WI O'Hare Field, Chicago, IL - John Polzer, past owner of Con-Cor Milwaukee Metropolitan Sewer District (MMSD) Sewer Manhole, Milwaukee, WI O'Hare Field, Chicago, IL Marquette Interchange, Milwaukee, WI UW-Madison Hospital, Findorff Construction, Madison, WI 30

Froedert Eye Clinic, Milwaukee, WI

The 48″ diameter holes pictured were drilled through a bank poured footing. The holes had to be drilled so that GC-Mortenson could excavate and pour deeper foundations for the new Eye Clinic building. The foundations were 36″ thick. The three holes were completed in three days. A double column set up had to be used to support the drilling equipment.

O’Hare Field, Chicago, IL – John Polzer, past owner of Con-Cor

This was the first recessed lighting job ever completed at O’Hare Field. There were multiple holes drilled at each location, not only to set the lights into the runway but also to recess the lighting and keep them flush with the surface of the concrete runway. This was done in 1972, long before the modern drilling equipment of today was invented. Con-Cor used a converted soil drilling rig to complete the job under budget and ahead of schedule.

Milwaukee Metropolitan Sewer District (MMSD) Sewer Manhole, Milwaukee, WI

This 40″ diameter hole was drilled for a 30″ diameter concrete sewer pipe. The connection was drilled through a typical 72″ diameter concrete manhole and the bench was approximately 24″. The hole was set up and drilled in 6 hours. This is one of many holes Con-Cor has drilled through manholes. The largest to date has been a 57″ diameter through a manhole and several water treatment facility walls.

O’Hare Field, Chicago, IL

The above scene is a picture of the converted soil testing drill rig used for drilling the recessed runway lighting on the O’Hare job. There were 293 – 20″ diameter holes drilled through the 15″ concrete runway and then 293 – 24″ diameter holes were drilled 5″ deep over the 20″ holes to create a recessed edge for the flush mount bi-directional lights. Con-Cor drilled a total of 798 holes with less expense and more precisely than traditional pre-formed sleeving methods.

Marquette Interchange, Milwaukee, WI

The above picture shows four Con-Cor employees setting up and drilling 9″ diameter holes 48-60″ deep on a 20-degree angle through secant pile walls. These holes were required for the tie backs for the new decorative concrete walls. Con-Cor drilled over 400 holes for Walsh, Marquette Constructors, and Hayward Baker.

UW-Madison Hospital, Findorff Construction, Madison, WI

Con-Cor crews had to drill three 30″ diameter holes 84″ deep because of improper placement of the reinforcing steel. As the crews drilled, reinforcing bars were slivered vertically and portions of the cores had to be chipped out entirely. The whole process took about 6 days to complete.

30″ Diameter Hole

Here is one of our Con-Cor employees standing in the 30″ diameter hole. As you can see, the holes were quite deep. Hydraulic jacks had to be used to break off the cores as they had to be drilled and snapped off in 30″ sections.

Milwaukee Metropolitan Sewer District (MMSD) Sewer Manhole, Milwaukee, WI

“Old School” is the title of this job. This hole had to be line cored or stitch drilled. A series of 3″ diameter holes were drilled through the 30″ thick wall to create a 60″ opening for a new connection. Sixty-four 3″ diameter holes had to be drilled to complete the opening. The job took 3 days to drill.

Racine Water Treatment Plant, Racine, WI

Con-Cor employees had to drill a lot of large diameter holes on this job. This is a picture of one of the 57″ diameter cores after it was pulled out from the opening. Con-Cor had to drill two 57″ diameter, four 40″ diameter, and two 36″ diameter holes along with several other smaller diameter holes on this major renovation of the Water Plant. There were also several wall sawed openings through the 21″ thick walls. One 72″ opening was cut in an octagon shape to minimize the concrete removal.