A new electrochemical method for consolidation of porous rocks

This work shows the preliminary results of a newly developed electrochemical method to seal the porous system of a building stone. The method is based on the use of porous rock as separator in a divided electrochemical reactor, where anolyte and catholyte compositions are selected in such a way that anions in catholyte and cations in anolyte can precipitate as a very insoluble salt. In our experiments, the insoluble salt chosen was barium phosphate. The results obtained show that barium phosphate precipitates in a small area near the catholyte side of the material. The area closer to the surface is where the maximum damage takes place. Accepting that the pore sealing is only produced in this region, the theoretical diminution of accessible porosity in this area should be approximately 25%.