Rob Johnson has been wielding a saw since he was in ninth grade back in the mid-1970s, core drilling holes in the walls at Primary Children's Hospital in Salt Lake City. His employers were his parents, Jack B. Johnson and Ruth Johnson, who founded A-Core Inc. in 1974 and still remain active in the firm. Ruth would pick him up from school and take him to work in the family station wagon, which doubled as the company vehicle for the fledgling business, recalls Johnson, now vice president of A-Core.
Today the Murray, Utahbased firm is one of the country's largest concrete cutting contractors, operating in nine western states with about 250 employees. The privately held company has doubled in size over the past eight years, says Johnson.
In three decades, Johnson has witnessed many advances in cutting technology, such as higher speeds, anti-vibration features, and electronic controls. "Basically the technique is the same but the equipment has evolved," he says. "Maybe the biggest improvement is the lighter weight of today's saws."
A-Core recently wrapped up work on a high-profile project: the $260 million renovation and seismic retrofit of the 90-year-old Utah State Capitol in Salt Lake City. Seismic base isolators were placed under 290 supporting columns to absorb horizontal force from an earthquake and reduce stress on the structure. The loads were transferred to temporary columns while the main columns were cut and the isolators positioned.
"Our job was to separate the building from its foundation so the isolators could be installed underneath," says Johnson. The A-Core crew used wire saws to cut through the thicker concrete segments--up to 7 feet thick--and wall saws for the thinner segments.
The task involved maneuvering around tight, awkward areas to accomplish the deep, intricate angles that were required. Workers experimented with various saws until Johnson called Husqvarna for a demonstration of the CS 2512 wire saw. "It was lightweight, very portable, and perfectly suited for the application," says Johnson.
In addition, A-Core cut openings on five upper floors to accommodate upgraded electrical, mechanical, and plumbing systems, and new windows and doors. Over the course of the project, A-Core's crew of 10 to 12 sawing technicians performed core drilling, wire sawing, flat sawing, wall sawing, hand sawing, and chain sawing. "We pretty much used all the tools available for the concrete cutting industry," says Johnson.
A-Core, which has received three internationally recognized awards from the Concrete Sawing & Drilling Association, serves a full gamut of concrete cutting applications, from houses to power plants.
This scope of work makesit essential for A-Core tomaintain a full saw inventory in its 10 locations. "Husqvarna has been responsive in meeting our demands, upgrading the equipment, and keeping it lighter," says Johnson. "Sometimes we'll design changes to a piece of equipment, such as a core drill wall saw, and take our ideas to them."