CSA A23.2-19-1C - Sampling plastic concrete

Sampling of plastic concrete represents the starting point for most concrete testing and the importance of following proper procedures cannot be overstated since any errors made at this stage of the testing progress can directly affect the results of the subsequent concrete testing procedures. Concrete samples are typically obtained in order to perform the following standard concrete tests: • Temperature of concrete • Slump of concrete • Plastic air content of concrete • Casting of compressive strength moulds In general, there are two types of sampling that a concrete field technician can perform: • Sampling for the evaluation of the concrete quality (most common) which involves obtaining a single concrete sample at the appropriate location within the load • Sampling for the evaluation of the uniformity of the concrete mixing process which involves obtaining three samples from distinct portions of the load and comparing the resulting slump, plastic air and density values to evaluate uniformity of the mixing process