Vol.14, No.3, 2014, pp.171–175
UDC 620.192.46:691.328

It is well known that the presence of cracks in reinforced concrete structures in aggressive environments accelerates rebar corrosion. The influence of real cracks in concrete structures on the penetration of chlorides and the resulting service life is being investigated in this study. Investigations are carried out at the Magnel Laboratory for Concrete Research of Ghent University in Belgium within a bilateral agreement with Politehnica University of Timisoara, Romania. Non-steady state migration tests are realized according to NT BUILD 492 using an electrical field and real cracks in order to determine the chloride profile. Samples with different crack patterns obtained by drilling from a reinforced concrete slab exposed to a simulated accidental failure of the central support and subsequent vertical loading until collapse have been used in the study in order to provide a more realistic image of the geometry of the cracks. The crack widths are measured using the optical microscope. The chloride penetration depth is measured with a colorimetric method on each specimen and the non-steady state diffusion coefficients are determined. For evaluating the parameters which have the most influence on chloride migration on the samples used in this experiment, a two-level factorial experiment is designed and carried out. The results obtained provide a better understanding of the diffusion process when dealing with concrete structures with real cracks.

Keywords: real crack, chloride penetration, crack width, non-steady state migration test, factorial experiment