Ray Heid Construction Ltd., St. Clements, Ontario, Canada, finished a 65,000-square-foot concrete driveway and parking lot in just 3 days using a power screed mounted on skis. The skis enabled workers to control screed elevations without the need for rails, forms, or other screed guides. The concrete driveway and parking lot, built for the Nova Steel Ltd. plant in Cambridge, Ontario, is 7 inches thick. Because of its size and thickness, the pavement required 1,390 cubic yards of concrete. The job was done in three pours, each taking a day to complete. The largest pour was 537 cubic yards.
The 2.3-foot-long steel skis bolt onto the main frame of any power screed, one ski at each end. Using a laser beam as a reference, the skis hydraulically raise or lower the screed to the desired elevation. The laser gives a signal to the receivers, which are mounted on masts at each end of the screed. This tells the hydraulics to go up or down to keep the screed level. For the Nova Steel project, the skis rode on a subbase of two layers of road gravel compacted to 100 percent proctor density. One worker controlled the laser while eight other workers raked and leveled concrete in front of the screed.