Risk analysis in quality assessment of ready-mixed concrete using fuzzy logic

The decision to include the considered batch of concrete in the designed class depends on the satisfaction of the conditions imposed on the strength of each individual result and the average value. The concrete conformity criteria are formulated in EN 206+A1:2016. When considering risk in concrete quality assessment, it can be assumed that there are three levels of result: low, medium, and high risk in quality assessment. Using logical operations on fuzzy sets, inference rules can be constructed to establish relationships between different variables. The paper presents an analysis of the risk of produced concrete carried out for two input parameters. Parameters on the average compressive strength of concrete and online defects obtained during compliance checks. Defects are identified by the probability of their occurrence. The third parameter introduced relates to the consequences of the occurrence of events identified with the obtained defectiveness after the compliance check of the compressive strength of the concrete produced. When verifying the compressive strength of concrete based on a sample size of n = 3, with the result obtained of a mean value of 28 MPa and a defect before and after conformity control defined at the medium defectiveness, the risk regarding the correct assessment of the quality of the produced concrete is medium.