Akademik Veri Yönetim Sistemi
ACTA GEODAETICA ET GEOPHYSICA, cilt.58, sa.1, ss.1-19, 2024 (SCI-Expanded)
Fracture toughness is an important parameter in determining the fracture mechanism of
rocks, concretes and other composites, and it is used in performing design and stability
analyses. In this study, the aim was to determine the effects of different environmental
conditions (dry, saturated, freezing, thermal shock and thermal aging) on fracture toughness
and fracture energy values of rocks from three different origins: gabbro, recrystallized
limestone and limestone. In the first stage, the physical, chemical, mechanical, mineralogical
and petrographic properties of rocks were determined. The material properties of
rocks were revealed by physico-mechanical tests, XRD, XRF and petrographic analysis. In
the second stage, the rocks were aged by exposing them to pre-determined environmental
conditions for a certain period of time and then, semi-circular bending strength tests were
applied to the aged rocks. SEM images were taken to determine the effects of different
environmental conditions on surface cracks. According to the experimental results, thermal
shock, thermal ageing and water saturation conditions led to decreasing fracture toughness,
while freezing conditions led to increasing fracture toughness. It was determined that thermal
shock was the environmental condition that caused the most weakening. In freezing
conditions, it was observed that physico-mechanical properties and fracture toughness values
of rocks increased. It was seen that the fracture toughness values of the monomineralic
structured samples were more affected by the environmental conditions than the multimineralic
rocks.