Division of Series of Concrete Compressive Strength Results into Concrete Families in Terms of Seasons within Annual Work Period

The basic concrete characteristic which needs to be controlled is the compressive strength of concrete, the values of which are subject to various random influences, for example climatic conditions, conditions of production and changes in the properties of components. The efficient control requires not only the registration of the decreased or increased concrete strength but also specifying the place and the date of application of concrete batch with characteristics deviating from the project assumptions. The article presents the control procedure, taking into account a division of the series of test results for the compressive strength of concrete from an annual production into concrete families of statistically stable strength parameters, in the identified time intervals. The article presents examples of verification of a hypothesis concerning the attachment of a set of compressive strength results to a concrete family, using selected statistical tests.