FDOT Concrete Field Inspector Specification Practice Exam

Cylinder strength is measured by applying axial compression to cured concrete cylinders until they fail. This test directly quantifies how much load the concrete can withstand in compression, which is the defining measure of its strength. Typically performed at specified ages (often 28 days), it uses a calibrated compression machine and a standard loading rate in line with the referenced test method (C39). The resulting compressive strength is what specifications use to determine if the concrete meets the required strength.

The slump test, by contrast, checks workability of the fresh concrete, not its strength. The air content test gauges the amount of air voids in the mix, which affects durability but not the direct compressive strength. The temperature test monitors the concrete’s temperature during curing, which is important for controlling setting and curing conditions but does not measure strength. Therefore, the cylinder compression test is the test method that provides the strength result needed.