New method for controllable accelerated aging of marble: Use for testing of consolidants

Research is needed on novel consolidants to restore weathered marble, because the available products exhibit limitations. To test new consolidants, samples with features similar to naturally weathered marble (i.e., near-surface damage) are recommended. We developed a novel method that produces decayed samples with a gradient in properties that can be tuned to any desired level, in terms of depth from the surface and decrease in dynamic elastic modulus. The idea is to produce near-surface damage by putting a marble sample in contact with a plate at a certain temperature for a certain time, calculated by a mathematical model. The model was used to predict the heating conditions to produce a certain decrease in dynamic elastic modulus in the first 1 cm from the surface, comparable to naturally weathered marble. Good confirmation of the model predictions was found experimentally. The suitability of using thermally “weathered” samples for testing consolidants was demonstrated in the case of a hydroxyapatite-based treatment. The mathematical model can be tailored to other lithotypes or ceramics, using the relevant property data.