Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 54 12 2023 02 20 Effect of Freeze-Thaw Cycles on Fracture Toughness and Strength Parameters of Travertine Effect of Freeze-Thaw Cycles on Fracture Toughness and Strength Parameters of Travertine 4589 4614 4953 10.22060/ceej.2022.20757.7521 FA Fardin Nezamivan Chegini Imam Khomeini international university Mehdi Hosseini Imam Khomeini international university Journal Article 2021 11 07 The present research investigates the effect of freeze-thaw cycles on mode I and mode II fracture toughness and strength parameters of travertine. In order to investigate the effect of freeze-thaw cycles on mode I and mode II fracture toughness, the samples were exposed to 0, 1, 4, 8, 16 and 32 freeze-thaw cycles and mode I and mode II fracture toughness were studied in different cycles. Confining pressures of 0, 2.5 and 5 MPa were applied to the samples to explore the effect of freeze-thaw cycles on strength parameters of travertine. Furthermore, microscopic studies were conducted to more precisely examine and evaluate the structural changes of the samples due to freeze-thaw cycles. Results show that mode I and mode II fracture toughness decrease exponentially as the number of freeze-thaw cycles increases. Mode I fracture toughness of the white and brown travertine were decreased after 64 cycles compared to 0 cycle as much as 35.48 and 37 percent, respectively and mode II fracture toughness of the white and brown travertine were decreased after 64 cycles compared to 0 cycle as much as 45.75 and 50 percent, respectively. Moreover, as the number of freeze-thaw cycles increases, triaxial compressive strength, uniaxial compressive strength, cohesion and internal friction angle decrease with regard to 0 cycle. Microscopic studies revealed that due to the freeze-thaw cycles, the microcracks of the stones propagate and new cracks are developed. The present research investigates the effect of freeze-thaw cycles on mode I and mode II fracture toughness and strength parameters of travertine. In order to investigate the effect of freeze-thaw cycles on mode I and mode II fracture toughness, the samples were exposed to 0, 1, 4, 8, 16 and 32 freeze-thaw cycles and mode I and mode II fracture toughness were studied in different cycles. Confining pressures of 0, 2.5 and 5 MPa were applied to the samples to explore the effect of freeze-thaw cycles on strength parameters of travertine. Furthermore, microscopic studies were conducted to more precisely examine and evaluate the structural changes of the samples due to freeze-thaw cycles. Results show that mode I and mode II fracture toughness decrease exponentially as the number of freeze-thaw cycles increases. Mode I fracture toughness of the white and brown travertine were decreased after 64 cycles compared to 0 cycle as much as 35.48 and 37 percent, respectively and mode II fracture toughness of the white and brown travertine were decreased after 64 cycles compared to 0 cycle as much as 45.75 and 50 percent, respectively. Moreover, as the number of freeze-thaw cycles increases, triaxial compressive strength, uniaxial compressive strength, cohesion and internal friction angle decrease with regard to 0 cycle. Microscopic studies revealed that due to the freeze-thaw cycles, the microcracks of the stones propagate and new cracks are developed. https://ceej.aut.ac.ir/article_4953_4ae1e2b07ecf6c799b91ed45e95278b8.pdf