Diamond tools are to concrete as fins are to fish: Without them, cutting, demolishing, drilling, polishing, and sawing would be impossible.
In January, World of Concrete attendees applauded four contractors whose work exemplifies particularly skillful use of these tools. The award-winning companies were chosen from 15 job stories published in Concrete Openings, the Concrete Sawing & Drilling Association’s (CSDA) quarterly magazine. Judges evaluated their work based on degree of difficulty, innovation, pre-planning, and quality requirements in four categories.
The only magazine devoted to concrete, asphalt, and masonry cutting, polishing, and imaging, Concrete Openings launched the awards program in 2013. Founded in 1972, St. Petersburg, Fla.-based CSDA is an international trade association of contractors, manufacturers, and affiliated members from the construction and renovation industries.
BUILDING CONSTRUCTION: Holes Inc., Houston; est. 1972
Company profile: wall sawing, slab sawing, core drilling, wire sawing, scanning, breaking, anchor bolt installation, demolition, and load and haul for commercial, industrial, residential, state highway, and municipality clients
Project: Houston Chronicle Building Renovation
Methods used: wall sawing and core drilling
General contractor: JM Design Build, Broadview Heights, Ohio
When Houston’s largest daily newspaper decided to move employees to a different building, eight window openings had to be cut through 12-inch concrete exterior walls to light conference rooms. Windows allow virtually no room for error, so this project illustrates how challenging renovations are. Contractor Holes Inc. drilled two 6-inch-diameter cores into each window location for rigging and two holes into the top of each opening to create a series of 8-foot-wide, 10-inch-tall relief pieces. The cutter completed 368 feet of wall sawing and core drilled 46 holes in two-, six-, and 10-inch diameters through the walls. Each piece weighed 13,200 pounds and was removed by crane.
INDUSTRIAL RENOVATION: Precision Concrete Cutting of Carey, Carey, Ohio; est. 1997
Company profile: ﬂat sawing, core drilling, wall sawing, hand sawing, curb sawing, scarifying and surface grinding for wastewater treatment facilities and rural bridge reconstruction; seven employees and four trucks
Project: Plastics Manufacturing Facility Refurbishment
Method used: slab sawing
General contractor: Clouse Construction Corp.; New Riegel, Ohio
Navigating the factory floor got groovy after Continental Structural Plastics in Carey, Ohio, expanded operations, what with more steel-wheeled carts moving more material around concrete slab placed in the 1960s. After deciding that installing 4-inch-wide, 0.25-inch-thick steel bearing plates would keep ruts from forming, the general contractor called in a 19-year partner to create slots that would house the reinforcing plates. Precision Concrete Cutting had two days to saw mill 1,026 feet of 0.25-inch-deep and 4-inch-wide openings. The project also required that an 11-foot radius groove and a 7-foot-radius groove be the same width and thickness and a 9-foot-radius groove to a depth of 1 inch with a 5-inch width.
INFRASTRUCTURE RENOVATION: J.P. Hogan Coring & Sawing Corp., Staten Island, N.Y.; est., apx. 1997
Company profile: Woman Business Enterprise and Disadvantaged Business Enterprise (WBE/DBE)-certiﬁed contractor provides core drilling, slab sawing, wall sawing, hand sawing, wire sawing, and selective demolition; 36 employees and more than 20 trucks
Project: New York City Department of Environmental Protection Water Siphon Replacement
Method used: core drilling
General contractor: Judlau OHL Contracting; College Point, N.Y.
Power plant, dam, and transportation projects usually involve extremely thick reinforced concrete in difficult-to-reach, potentially hazardous locations. A 48-inch slurry wall stood in the way of a New York City Department of Environmental Protection water supply project. When called in to cut a 79-inch hole through it, J.P. Hogan Coring & Sawing Corp. had Husqvarna Construction Products fabricate a 79-inch-diameter, 5-foot-long core drill bit and powered it with a 45.6-cubic-inch Diamond Products motor. Working in a 25-foot-deep trench, the operator controlled coring speed at 41 RPM, adjusting as necessary when the bit encountered any steel reinforcement. The core took eight days to create and weighed 23,000 pounds.
ROADS, BRIDGES & AIRPORTS: Core Cut Ltd., West Lothian, Scotland; est. 1978
Company profile: core drilling, slab sawing, hand sawing, wall sawing, wire sawing, selective demolition, ﬂoor polishing and preparation, and hydrodemolition; 40 operators
Project: Glasgow Queen Street Tunnel Upgrade
Methods used: slab sawing, core drilling, wall sawing
General contractor: Story Contracting
At $1.54 million, renewing the 40-year-old concrete track beds in Scotland’s busiest subway station was the country’s largest diamond drilling project. Core Cut Ltd.’s role involved 5,906 feet of slab 19.7 inches to 29.5 inches thick. Working around the clock to finish within 20 weeks, crews drilled 8,500 holes and sawed 9,022 feet in a pre-blockade phase. The second, main blockade phase included 12,139 feet of 20.5-inch-deep longitudinal slab sawing and more than 1,500 transverse cuts of 11.5 feet. A robot reduced 10,000 of concrete into manageable sections that were removed by train.