CRACK-BRIDGING ABILITY AND LIQUID WATER PERMEABILITY OF PROTECTIVE COATINGS FOR CONCRETE

A surface coating for concrete can be exposed to a wide range of envir onments, movements and stresses depending on which application the str ucture is used for. Therefore the coatings have different requirements to satisfactorily protect concrete constructions in different service environments. Water permeability is an important factor to be conside red in evaluating the performance of a coating since water penetration generally leads to the degradation of the substrate (concrete) and/or to the electrochemical reaction of steel when it is present (reinforc ed concrete). The crack-bridging ability of coatings is another import ant characteristic that has to be evaluated to assess if a coating can protect a concrete structure which surely will crack. This study inve stigates the relative importance of the parameters water permeability rate and viscoelasticity of coatings for different applications. (C) 1 998 Elsevier Science S.A.