A pavement placed in Kansas City by Clarkson Construction Company was not an ordinary paving job. Job-cured cylinders broke at 4600 psi after only one day. Although the concrete will be exposed to harsh winters, no air-entraining mixture was added at the batch plant. The concrete was made with a blended hydraulic cement that contains a proprietary addition to speed strength gain and improve durability. Within four hours of mixing, concrete made with the cement typically gains compressive strengths of 2000 to 3000 psi and flexural strengths of 500 psi. Because of its good strength gaining performance, the cement is ideally suited for repair projects. It also resists sulfate attack and damage caused by deicers and freeze-thaw cycles.
The pavement in Kansas City was placed in early October with air temperatures at about 45 degrees. Air content of the 1-inch-slump concrete was 3.8 percent, but the cement manufacturer says this is entrapped, not entrained, air. Concrete made with the cement reportedly resists freeze-thaw damage without entrained air. Because of the low water-cement ratio there was no bleed water and finishers occasionally used a fog spray when hand floating was needed.