Investigation of the effect on phycico-mechanic characteristics of the water content dependent upon porosity in the tuffs used as a building stone in Afyonkarahisar

In this study, tuff which is extracted from Ayazini and Seydiler precincts and used as building stones in Afyonkarahisar district is examined according to the effect of porosity-related water content on physicomechanical properties. To do this, mineralogical and petrographical examinations (polarizing microscope, SEM, XRD) as well as chemical (XRF), physical and mechanical tests haven been made on tuff samples from both precincts, and the results are interpreted according to their relations with porosity.From porosity measurements and SEM images, porosity and average pore size of Ayazini tuffs are determined as 37.3% and 2.9 µm, and porosity and average pore size of Seydiler tuffs are determined as 36%, and 5.98 µm, respectively. Later, the way porosity effects tuff's mechanical strength is examined. For this, mechanical properties of waterlogged samples are compared to others which are dried by natural means. As a result, compared to dry samples, uniaxial compressive strength and bending strength of Ayazini tuffs saturated with water for 48 hours are decreased by 44% and 43% respectively, and uniaxial compressive strength and bending strength of Seydiler tuffs saturated with water for 48 hours are decreased by 52.5% and 46% respectively. Considering these results, it is determined that porosity levels are extremely important depending on areas of usage of tuffs.