A new electrochemical method for consolidation of porous rocks

This work shows the preliminary results of a newly developed electrochemica l 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 reacto r, where anolyte and catholyte compositions are selected in such a way that anions in catholyte and cations in anolyte can precipitate as a very insol uble salt. In our experiments the insoluble salt chosen was barium phosphat e. The results obtained show that barium phosphate precipitates in a small area near the catholyte side of the material. The area closer to the surfac e is where the maximum damage takes place. Accepting that the pore sealing is only produced in this region, the theoretical diminution of accessible p orosity in this area should be approximately 25%. (C) 2001 Published by Els evier Science B.V.