The influence of methods of concrete quality control by physical and mechanical parameters on the reliability of building structures

Introduction. The construction technical control system evaluates the physical and mechanical properties of concrete on the base of testing a series of samples taken from a batch of concrete. It is necessary to take into account the influence of the control method on the quality of concrete structures and their reliability. Aim. Creation of a technical control system that should eliminate the causes of the identified risks by reducing the impact of the identified causes. Materials and methods. The control method affects the reliability of concrete structures being built and is evaluated from the point of view of choosing the number of samples and discarding the minimum strength values in the series. The results of the control of a series of concrete samples for 6 samples selected in such a way as to ensure compliance with the declared class when discarding 2 minimum sample values are compared. Results. As a result of the analysis of the impact of the methodology on quality and reliability: class B turns out to be 2 steps lower than the prescribed one, the in-series coefficient of variation exceeds the permissible one by 8 %, and the reliability level is significantly lower by 36 %. Conclusions. The conducted research shows an underestimation of the methodological component of material control, which can leave significant gaps in the system of technical control of construction products and does not allow to ensure the required level of reliability of structures.