Análise da vida útil estimada das edificações baseada na norma de desempenho (ABNT NBR 15.575:2013)

Abstract

Analysis of service life of a building requires the observation of many variables, especially corre-lating to the performance and durability. In this meaning, the NBR 15.575:2013 - Residential Buildings - Performance establishes requirements, criteria and methods assessment for analyz-ing the performance of buildings, and sometimes subsidize designers to determine the design life consistent with the performance level desired by the builder and user. Adding that the calculation of the estimated service life of buildings takes into account the natural aging of the building sys-tems components, but not contemplates of the damage effect caused by the entry into operation and use of the building or absence conservation. Moreover, the NBR 5.674:2012 - Buildings Maintenance - Requirements for the maintenance management system, indicates which systems and services that must go through the maintenance process and in what period, enabling mainte-nance management quality. However, it is not always what happens in the buildings after entry into operation and use. In the survey, we tired so verify the relationship between the predicted service life and the warranty period of the building. The information analyzed were provided by an active construction of Recife, collected in a database from the technical assistance after work eight buildings in the Metropolitan Region of Recife. To measure the percentage difference be-tween the design life and estimated service life, following the intervention of the technical assis-tance after work was used the factors method set out in ISO 15.686:2000 - Building and construc-tion assets - Service life planning and recommended by NBR 15575-1:2013. The frequency of occurrence damage in buildings was analyzed by determining the rates of failure in the buildings. The results show to a reduction of the design life of the order of 20% of the reference service life, from values adopted in the Performance of Brazilian Standard; also point to a concentration of damage in the initial stage of construction, above 50%, which correlate with the conditional prob-ability of failure curve (Bathtub Curve) sorting a high abrupt failure rate, ranking the building at the stage of infant mortality. These results reflect an unplanned variation in performance level proposed for the building. In this context, it is suggested to link the period of the works guarantee to the level of actual performance of the building. The application of reliability concepts allows infer about warranty period of the Building and make comparisons with the requirement of Brazi-lian law enforcement.