Influence of moisture content of samples on the depth of penetration of water under pressure

The article deals with the impact of samples moisture content on the results of the depth penetration of water under pressure according to EN 12390-8, considering the fact, that technical standard does not prescribe definite condition of the samples prior testing. To obtain results of the water penetration depth, samples from eight different batches (strength classes from C 12/15 to C 55/67) were prepared. The experiment simulated two boundary conditions: saturated samples were tested immediately after taking from the water. This procedure of samples treatment was marked as the reference (REF). The second one: oven dried samples were tested after cooling to room temperature. This procedure of samples treatment was marked as the comparative (COMP). The results showed an increased tendency in the penetration depth when the samples were oven dried compared to the reference method. There is also discussed the substance, aim and relevance of the technical standards in connection with practical use. (paper)