A prediction model for uniaxial compressive strength of deteriorated pyroclastic rocks due to freeze–thaw cycle

• Pyroclastic rocks are the most affected rocks from freeze-thaw cycle among building stones.
• Engineering properties of pyroclastic rocks from the Cappadocia region were studied.
• Estimation of uniaxial compressive strength of pyroclastic rocks after freeze-thaw cycle.
• Percentage loss of uniaxial compressive strength of pyroclastic rocks after freeze-thaw cycle.
• A statistical model developed to estimate the UCS of pyroclastic rocks to indicate the impact value of F-T cycle.

Either directly or indirectly, building stone is exposed to diverse atmospheric interactions depending on the seasonal conditions. Due to those interactions, objects of historic and cultural heritage, as well as modern buildings, partially or completely deteriorate. Among processes involved in rock deterioration, the freeze–thaw (F–T) cycle is one of the most important. Even though pyroclastic rocks have been used as building stone worldwide due to their easy workability, they are the building stone most affected by the F-T cycle. A historical region in Central Anatolia, Turkey, Cappadoia encompasses exceptional natural wonders characterized by fairy chimneys and unique historical and cultural heritage. Human-created caves, places of worship and houses have been dug into the pyroclastic rocks, which have in turn been used in architectural construction as building stone.Using 10 pyroclastic rock samples collected from Cappadocia, we determined the rock’s index-mechanical properties to develop a statistical model for estimating percentage loss of uniaxial compressive strength a critical parameter of F-T cycle’s important value. We used dry density (ρd), ultrasonic velocity (Vp), point load strengths (IS(50)), and slake-durability test indexes (Id4) values of unweathered rocks in our model, which is highly reliable (R2 = 0.84) for predetermination of percentage loss of uniaxial compressive strengths of pyroclastic rocks without requiring any F-T tests.