Failure patterns associated with facade zones and anomalies in the initiation and propagation of degradation

Abstract

• Detachment is the most frequent anomaly and its association with the continuous walls zone is the most critical condition. • Continuous walls are areas with the highest incidence of anomalies, and transitions between floors are the areas of greatest severity. • The factors and mechanisms that control degradation are different in initiation and propagation. • Combined effects between agents, mechanisms and anomalies are more important in propagating than the initial effects causing the anomalies. The degradation of facades and the evaluation of their service life can be quantified from the evolution of failure patterns in the elements. It is possible to quantify the level of degradation and evaluate frequency and severity indicators. The objective of this study is to quantify the degradation in a field database and associate this degradation with the facade zones in which they occur. For this, a database of facades of inspected buildings is selected, with samples of different ages and levels of degradation, where the quantification is measured using the Degradation Measurement Method. Then, the failure patterns in the different zones that make up the facades are investigated to observe relations that determine and explain the degradation. The evaluation of the results is conducted under two conditions: initiation and propagation of degradation. The initiation is considered until it reaches the service life limit, and the propagation is considered when it is exceeded. The results show that, in the Continuous Wall zone, the frequency of occurrence is the highest for degradation, and the Transition Between Pavements zone is the one with the greatest degradation severity. The major anomaly is ceramic detachment, followed by joint failure. In conclusion, it can be stated that the failure patterns indicate that the factors that control degradation in the initiation are different from those that control the propagation, which is evidenced by the distribution of anomalies observed in the two phases.