Concrete testing - wet and dry : Baxter, M 1F Civ Engng Nov. 1974, P43–45

Abstract

The article introduces a new method of testing concrete and reviews some of the problems of existing testing procedures. The cement and concrete association (c&ca) have developed A machine costing found1250 which runs on 240 volts electric supply and reads out the cement content of an 8 kilogramme sample of concrete with a standard deviation of 21 grammes. If pulverised fuel or similar cement substitute is present the machine cannot distinguish between the two. A subsidiary test is then required to determine the proportions accurately. The operator has to put in 8 or 10 kilogrammes of fresh concrete and in about 5 minutes time a graph is obtained of the cement content, the machine cleans itself during the operation and there is no danger of dried concrete affecting the accuracies of the next test. The main advantage of this method is that the testing is done before the concrete is laid. /TRRL/