Análise estatística e teste de conformidade do concreto em diferentes resistências: estudo de caso

Abstract

The determination of concrete compressive strength has conventionally been used as a criterion for technological control in construction projects. Thus, conducting compressive strength tests is the primary method for determining the compliance of a batch of concrete, standardized by ABNT 12655:2022, which defines criteria for the production and approval of concrete batches, aimed at ensuring excellence in reinforced concrete structures. Consequently, this study collected the compressive strength results of concrete from C25 and C30 classes, with these materials being used in the same construction and supplied by a single concrete services company, with the purpose of applying the acceptance standards established by the mentioned norm. From this, it was possible to identify that regardless of the characteristic strength class, the acceptance rate for concrete batches remained at 100% for both classes. This result ensured the absence of serious deficiencies in the technological monitoring processes associated with concrete manufacturing, and through statistical analysis, such as the standard deviation, 0.91 (C25) and 1.44 (C30), were obtained. The coefficient of variation was 1.31 (C25) and 0.84 (C30). Therefore, it was possible to demonstrate an excellent level of reliability (level 1) of the ready-mixed concrete used in the specific project, in addition to the conformity identification procedures of the various batches analyzed. Hence, although compliance occurred for all batches in the two classes analyzed, technological control practices continue to be of utmost importance for the success of a project, as they identify possible deficiencies in production procedures that may require correction.