Chloride penetration dependency on freeze-thaw testing cycles

Concrete research is focusing ever more on the combined effect of degradation mechanisms on the durability of reinforced concrete structures. While most of the research has been directed at combined carbonation and chloride penetration, recently some attention has been given to emulate combined degradation conditions, especially those existing in Nordic countries (frost attack/chloride penetration), with regards to the harsh environmental conditions. Frost attack of concrete effects the chloride penetration by reducing the concrete cover, and more importantly, by changing the characteristics of the surface and internal concrete due to cracking. Recent research has shown there to be a synergetic effect, but no steps have been taken to characterize and comprehend the mechanisms involved, and to develop a procedure to make it possible to transfer this knowledge to the industry and into practise. As part of an ongoing research progress addressing this need, series of tests were undertaken to ascertain what influence freeze-thaw cycles would have on the transport of chlorides into concrete. In this paper the, the preliminary result of this research project are presented.