Cryofracturing effectiveness using liquid nitrogen on granite: Fracture toughness and Brazilian tests following freezing-thawing cycle

• DOI: 10.1016/j.rineng.2024.101895
• Publication Date: 2024-02-09T17:41:49Z
• Authors: Sotirios Nik Long...; Piotr Skrzypacz; Randy Hazlett
• Keywords: Liquid nitrogen; Thermal shock

The influence of repeated liquid nitrogen (LN2) exposure treatments on the geomechanical integrity granite samples from Kazakhstan was investigated using measures fracture toughness and indirect tensile stress (Brazilian tests) with initial temperatures ranging 100 °C to 500 °C. These tests were compared baseline conducted at 50 without LN2. Our research indicated that LN2 treatment in freezing-thawing cycles can significantly degrade strength, making permeability enhancement mechanical impairment more pronounced. In Brazilian test, peak load before specimen failure decreases as sample temperature difference between boiling point 1 atm increases, duration increases. semi-circular bend (SCB) LN2-treated specimens' also decreased when differential increased. specimens heated an showed most substantial alteration, thermal shock generated numerous new fissures created extensions pre-existing ones, yielding increased plastic behavior. Scanning Electron Microscope (SEM) analysis confirmed formation or prolongation fractures. novelty this work is combination corroborate alteration both behavior rock strength subjected shocks varying magnitude confirmation dramatic granites above 300