In-situ performance of CPF concrete in a coastal environment

The paper describes the work of an investigation carried out to evaluate the performance of controlled permeability formwork (CPF) in a seawall. Tests were carried out in the splash (SP) and inter-tidal (I/T) regions of the seawall at two locations (built in two phases, approximately 1 year apart), which used CPF, and on a groyne where the system was not used (reference (Ref) concrete). The tests were made both in-situ and on cores removed from the walls, in the laboratory. Properties measured included, core strength, surface hardness, capillary porosity, absorption, carbonation, chloride profiles, half-cell potentials and concrete resistivity. The results indicate that CPF gave improved performance compared to the Ref concrete for almost all properties. Comparisons with other laboratory and early site-based data indicate that the benefits observed in these for CPF concrete were obtained in the test concretes of the study. In addition, there appeared to be no depletion in CPF concrete performance due to the aggressive conditions.