Avaliação da integridade mecânica em paredes de taipa de pilão utilizando a técnica do ultrassom: utilizando a técnica do ultrassom

Abstract

This thesis presents a study on the development of a methodology for ultrasonic tests applying to prototypes walls in rammed earth. The first and second phases were successfully realized, proving the existence of a correlation between mechanical strength and ultrasonic velocity in earth materials. Searching to achieve the objective, the research was conducted in five stages. In the first stage, was elaborated a study about rammed earth construction technology. In the second, technical visits were realized on map buildings erected using this building technology, in Minas Gerais state. In a third the soil to be worked was chosen, taking into consideration the type of soil used in the second stage of the research project. In the fourth stage, geotechnical tests were conducted in order to understand the behavior of the chosen soil. On the fifth phase, ultrasonic tests and compressive strength test were conducted. At this research stage, a small wall was constructed, presenting similar thickness to the existing walls built during the Brazilian colonial period, where ultrasound tests were performed. After, at the tested points, specimens were removed and were submitted to compressive strength tests. The results generated from both tests were analyzed, seeking to determine the existence of the correlation between the pairs. Although results showed a low correlation between ultrasonic velocity and simple compression strength, when performed in prototypes with similar dimensions to the existing rammed earth walls, it would be premature to affirm the use of ultrasound inadequacy as a nondestructive method of verifying the presence of cracks in existing walls built in this constructive technique. Analyzing the obtained data, it was verified that the ultrasound, with the aid of an amplifier, is able to generate valid results. Therefore, it is hoped that this work may be a contribution to development studies on the use of non-destructive testing in the evaluation of structure walls built with earth material, among them, the rammed earth.