The slabcon test, more commonly known as the slump test, is used to measure the workability or consistency of freshly mixed concrete. By placing concrete in a cone-shaped mold and measuring the amount it subsides (slumps) after the mold is removed, the test provides a quick and simple way to ensure that the concrete mix has the desired fluidity for a specific application. This helps in verifying the water content and the quality of concrete batches, ensuring uniformity for construction projects.