Comparative analysis of the mechanical properties of water saturated and air dry volcanic tuffs

Abstract

Volcanic tuffs were tested under laboratory conditions to obtain data on the influence of water content on the strength. The studied lithologies included rhyolite tuff from NE Hungary, andesite tuff from Central Hungary and basalt tuff from central western Hungary. Tests included the determination of density, ultrasonic pulse wave velocity, the uniaxial compressive strength (UCS) and modulus of elasticity of both dry and water saturated specimens. The samples were fully immersed into water until full saturation was reached, following the descriptions given in EN 13755:2008 and densities were measured prior and after the saturation (EN 1936:2007). The ultrasonic pulse velocities were measured according to EN 14579:2005, while uniaxial strength was determined as described in EN 1926:2007 standard. Modulus of elasticity was calculated. The mechanical properties of dry and water saturated specimens were compared and the relationships between these parameters were analyzed by using statistical methods. A linear relationship was found between air dry and water saturated UCS of tuffs. Density and UCS were also correlated, with exponential equations for both airdry and water saturated tests conditions.