Correlation between the properties of structural clay blocks obtained by destructive tests and Ultrasonic Pulse Tests

The use of building constructive systems based on structural ceramic blocks masonry has experienced in Brazil a great advance in past decades. This is being associated with successful government housing programs for low income people. However, the system still lacks detailed studies to improve the construction quality. To evaluate the quality of ceramic blocks the use of destructive tests are conventionally carried out to standard required parameters such as mechanical strength and water absorption. These destructive tests are costly and time consuming. In many cases they demand sophisticated laboratory equipment's. Thus, the objective of the present work is to correlate destructive tests results with those of faster and less expensive non-destructive methods to determine the compression resistance and water absorption required by the standards of structural ceramic blocks. Ceramic samples, using two different clays, were sintered at temperatures from 800 to 1000 degrees C and subjected to conventional compression, water absorption and dimensional tests, as per the Brazilians standard. Ultrasonic Pulse Tests (UPTs) were also perform and correlations were established with the conventional properties. Results of this comparison indicate, for the first time, that it is possible to use UPTs to evaluate to qualify structural ceramic blocks.