An Integrated Study of Water Weakening and Fluid Rock Interaction Processes in Porous Rocks: Linking Mechanical Behavior to Surface Properties

We investigated the impact of water weakening on mechanical behavior Obourg Chalk and Ciply (Mons Basin, Belgium). Different tests were conducted to estimate unconfined compressive strength (UCS), tensile strength, Young’s modulus, under triaxial loading, critical pressure, fracture toughness, cohesion, internal friction coefficient samples either dry or saturated with brine. This extensive dataset allowed us calculate wet-to-dry ratios (WDR), i.e., ratio between any property for a sample that water-saturated sample. For both chalks, we found has strong effect WDR ranging from 0.4 0.75. exhibits more than Chalk. The highest was obtained UCS, modulus. Weakening effects are still present in brine-saturated but their magnitude depends fluid composition. data correlated variations surface energy derived three different methods: mechanics, contact angle goniometry, atomic force microscopy. Water tested chalks can be explained by clear reduction existence repulsive forces which lower cohesion.