THE EFFECT OF SEA TIDES ON HISTORICAL BRICKWORK IN VENICE

The conditions of historical brickwork in Venice are very peculiar ind eed because the presence of seawater influences, directly or indirectl y, the wall systems. We have initiated a study concerning the physical and chemical effects of water on the brick walls along the canals, wh ich are usually submerged during the sea high tide. The situation exam ined is the worst one, since both the cyclic contact of brickwork with water and the physical effect of wave movements occur concurrently. C hemical analyses and porosity measurements have been performed on samp les taken from walls of different age and exposed differently to the t idal waters. Tests have been performed on the samples at various depth s, in order to evaluate the changes in the parameters and to define th e relationships among the physical and chemical processes leading to t he decay of the material.