Conformity testing of concrete compressive strength based on overlapping groups

Abstract

Conformity testing carried out according to the standard PN-EN 206-1 concerning compressive strength allows the use of two computational procedures. Standardized criteria are checked on a series of a fixed number, created with subsequent strength measurements. The series may overlap or be non-overlap. This paper presents the analysis of the risks borne by the manufacturer using these computational procedures carried out during the compulsory conformity testing. The risk assessment was carried out by means of the operating characteristic (OC-curve). Probabilities of acceptance have been determined using the Monte Carlo simulation method . The calculations of results have shown that the aggregation of data in the series does not affect the risk of rejection of a „good” concrete batch. The author recommends conformity control based on the results of overlapping sequences due to the possibility of early detection of non-compliance, which gives the opportunity to take corrective action as soon as possible.