Non-Destructive Techniques for Characterising Earthen Structures

== Abstract ==

Earthen  architecture  is  one  of  the  most  relevant  building  technologies  among  heritage structures. However, mechanical properties are commonly obtained from destructive tests.  To  contribute  at  changing  this  trend,  two  non-destructive  mechanical  techniques  (ultrasound and modal analysis) are studied to determine their ability at characterizing earthen materials and their possible correlation. 
To  achieve  these  purposes,  twenty  cubic-shaped  earthen  specimens  were  produced  for  testing the  capability  of  ultrasound  transmission  method  to  control  moisture  content  and  its  evolution during drying process at different environments. Additionally, a real-scale rammed earth wall was built to assess the feasibility of using ultrasound technique to determine elastic dynamic Young modulus. This analysis was validated by indirect comparison with experimental modal analysis test results. 
The  most  important  findings  are  that  the  relationship  between  moisture  content  and  ultrasound transmission speed is linear. This information is useful to control the drying process of  earthen materials  and  to  control  the  moisture  content  distribution  on  larger  in-service structures. Finally, numerical simulation using ultrasound transmission data as input information allow to predict the vibrational response of the tested wall with an error around 3%.

== Full document ==
<pdf>Media:Draft_Content_736753825p558.pdf</pdf>