GWT - New Testing System for “in-situ” Measurements of Concrete Water Permeability

The paper presents principle of a German's Water permeation Test (GWT) and results of experimental study which was carried out to assess a possibility to implement in engineering practice a new testing system (GWT) for assessment of water permeability of concrete with the respect to a new European Standard (EN 12390-8). The testing details and procedure of evaluation of the results obtained by means of GWT have been also described.Research program consisted of laboratory tests and “in-situ” examinations of three concrete bridges situated along the national road nr 3 in Lower Silesia, Poland, close to Wrocław. Two types of concrete have been considered. Examinations carried out have shown that the results of standard water permeability measurements are with the agreement of “in-situ” NDT tests performed by means of GWT system. Obtained results confirmed that this new method is very useful for engineering practice. The “average flux of water” (qm) has been proposed as an evaluation parameter. It has been shown that concrete can be considered as water permeable if qm ≤ 0.32μm/sek.