Análise da capabilidade em testes de resistência de corpos de prova de concreto

Abstract

It is not new that in the industrial sector process control is a priority in any company, because processes that do not have control, incur waste and products with undesirable quality. The quest for continuous improvement must be unceasing because, through it, the company will ensure survival in the market by reducing waste and standardizing processes. Statistical control of the process is a strong ally to raise the competitive level of companies, since it uses a methodology based on practical tools and simple implementation, seeking the continuous improvement of processes, optimizing time and cost of production. At this way, control charts are one of the most important statistical control tools of the process. They have a statistical based on data analysis and help us to visualize biased behavior in the the variability of the process. Furthermore, it is an easy application tool with little recourse for the company that chooses to use them. Control charts provide important information regarding the control limits of a production process, each variation outside the control limit must be studied for healing. The main objective of this paper was to evaluate the strength of concrete specimens with curing of 7 days, which were removed from the productive process of concrete posts. NBR5739 / 1993 determines that concrete for this type of product must have a minimum of 25MPa compressive strength. So the study found that the process was not adequate to the regulatory standard and therefore classified it as out of statistical control. In order to support this classification, process capability indices were calculated which facilitated the interpretation of the data. The causes of process variation were analyzed and a plan of action was developed to minimize their impact. The techniques proposed by the statistical control of the process were effective in showing the company the importance of having a standardization of the process, with the lowest possible variability. At this way, they could better plan the production in relation to the consumption of the concrete inputs, as well as manage to dilute costs of standardizing the production process.