Applicability of an accelerated test for long-term performance estimation of hydrophobic treatment for reinforced concrete structures

Rebar corrosion in reinforced concrete structures does not only lead to high maintenance and repair costs but also causes problems related to user’s safety. Preventative methods may prolongate the structural service life by limiting corrosion initiation and/or propagation. One among those are the so-called hydrophobic pore lining treatments which are limiting the penetration of water and can promote the dry condition into the concrete. However, only little infor-mation is available regarding the long-term performance of this products. The lack in knowledge does not only regard the influence of the coating on different durability relevant parameters (water penetrabil-ity, breathability, …) but also the possible degradation of the latter. A prediction of the long-term behaviour of a coated structure is thus difficult and even more, time con-suming. This paper is discussing the applicability of an accelerated test procedure carried out in order to evaluate the long-term behaviour of a coated structure. Reinforced concrete samples were prepared and subjected to accelerated carbonation. One carbonated sample was coated by a hydrophobic pore lining treatment and the other one was left uncoated. The samples were then initially submitted to atmospheric conditions of Milano (2 years) and subsequently moved to an accelerated chamber applying a 48 hours cycle that simulates a harsh atmospheric exposure (rain, wind, IR and UV- radiation). By comparison of the results of the coated and uncoated sample obtained during atmospheric and accelerated exposure, the effectiveness of the accelerated test procedure for the evaluation of the long-term performance of the coated reinforced concrete structures was analysed.