Simulation of a portuguese limestone masonry structure submitted to fire: 3D ultrasonic tomography approach(Article)

A multianalytical approach combining 3D ultrasonic tomography, FESEM, capillary absorption coefficient, open porosity and elastic constants (s, E, μ and K) has been applied to characterize the extent and severity of Lioz limestone decay processes induced by fire, as well as the performance of two consolidants (ethyl silicate and nanolime). Samples (15 cm × 3 cm × 3 cm) were partially buried in fine sand (to mimic the real situation of stone blocks in masonry structures) and a section of 15 cm × 3 cm × 0.5 cm was exposed to direct heat (600°C). The region directly exposed to heat exhibited lower P-wave velocity and more intense fissuration whereas the areas more protected showed thermal etch pits structures. Ethyl silicate showed better performance than nanolime and 3D ultrasonic tomography allowed estimating the depth reached by this consolidant.