Calcium Carbide Test –
The moisture content of the screed is assessed by testing a sample of the screed using a carbide moisture meter. A sample of the screed is removed at approximately 50% of the screed depth, and the weight of the sample is measured accurately. The removed screed sample is further mixed with a calcium carbide reagent and subjected to orbital rotation in a vacuum flask. The results are displayed on a pressure gauge as CM%. The test is relatively quick and easy to carry out, and yields accurate results. However, as the calcium carbide method is a destructive form of testing, minor remedial repairs would generally be necessary for the screed area from where the sample is removed.