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Services : Saving & Drilling Concrete

Anytime you need to put a hole through concrete, masonry or solid rock, you will want to call on a drilling specialist. He will very likely use one or more diamond core bits, mounted on a drilling rig or a multi-drill, gang-drilling machine. Typical applications include walls, pavement, tunnels, bridge parapets, ceilings, roofs, mine facings, roadside rock shapes, and so on.

Often the holes are made to route cables, conduit, pipes, wires, or other "thru the structure" components. Other times the holes are made to anchor bolts or lifting rods. Still, other times the holes are made simply to place explosive charges. Sometimes to install load-carrying devices, like dowel bars. There are probably thousands of reasons for making holes in concrete. Whatever the reason, the holes are normally made with the core bit.

Core bits consist of the bit tube, which has diamond segments or a full crown brazed or welded on the drilling end.

Bit sizes range from 1" diameter to 48" diameter. The bits are mounted on the rotating shaft of various types of drilling machines. Some are large drilling columns, some are track mounted, some are mounted in groups on specialized, multi-hole drill rigs, and some are even hand held drills.

The applications highlighted in the photos are representative of the many different types of holes drilled every day by members of CSDA.

Think of those square, rectangular or large round openings you often see in concrete walls for doors, windows and vent casings. The corners of the square and rectangular openings, as well as the very large round holes may well have been made by a technique called stitch drilling. A series of small holes are made so close together that they overlap. That has the net effect of making a curved hole in the wall when all the holes are completed and the center section is removed. The numerous rounded edges that remain are removed by grinding to leave a clean, neat opening.

Another use for stitch drilling is to sever very thick concrete blocks, which are beyond the cutting depth of the largest saw blades.

Core bits from 4" to 6" in diameter are typically used for stitch drilling, although larger diameter bits can be used. Drilling rigs similar to those used for core drilling are used, although most are track mounted when the concrete is inclined or vertical.

Typical stitch drilling applications by CSDA members are shown in photographs.

The term "flat" refers to the concrete surface. If you have a surface you need cut that is reasonably level, this type of sawing would normally be chosen. Flat sawing is commonly done on pavement, floors, bridge decks, dams, culverts and similar tastes. It is typically done to provide expansion joints, to remove damaged pavement sections prior to patching, to clean and prepare random cracks for repair, to insert pipes, conduit and electrical cables into concrete, for demolition purposes and many other reasons.

Saw blades with diamond segments around the periphery are normally used for flat sawing. Blades may vary in size from 4" diameter to 60" diameter. Saws range from 5 HP up to 65 HP in gasoline, diesel and electrically powered versions.

The photos you see here are typical applications that were completed by members of CSDA. Keep in mind that sawing comparatively flat surfaces is commonly done all over the world; however, each project is somewhat unique and requires special skills to do it properly.

Vertical surfaces and surfaces inclined to the point that flat saws cannot be used are the application areas for wall saws. Sawing door, window and conduit openings in newly poured concrete walls and in structures being rehabilitated constitutes the major application for wall saws. However, they are used on many other vertical concrete surfaces, such as car inclines, dam spillways and turbine tubes, factory equipment pads, missile silos, highway median barriers, bridges, tunnels, levee walls, aquarium tanks, power station stacks and so on.

Wherever they are used, four components are involved - the blade, the track, the power unit and the wall saw. The diamond wall saw blade consists of a core with diamond segments on the perimeter. Blade sizes run from 12" diameter to 72" diameter. The blade itself is mounted on the saw spindle. The spindle runs along a vertical track normally bolted to the wall. The unit is powered pneumatically, electrically or hydraulically by a remote power unit.

The applications shown here are typical wall sawing projects, all done by CSDA members.

Other Services:  Wire Sawing, Breakout Removal, Joint Filling, Concrete Replacement