Effect of loading on carbonation penetration in reinforced concrete elements

Concrete tensile microcracking due to a mechanical loading enhances the dif fusion of aggressive agents from concrete cover to the reinforcements, whic h leads to the beginning of the propagation period of steel corrosion. The purpose of this work is to quantify the effect of concrete microcracking on CO2 penetration. Concrete carbonation was studied on two 13-year-old reinf orced concrete beams subjected to atmospheric carbonation. Indeed, these be ams were exposed to the climate of the south-west of France but in a covere d place and were always stored in a loaded state. Because the microcracking network is quite impossible to characterise, the tensile stress in the rei nforcements was chosen as the main parameter of the microcracking state. Th is investigation results on a proposed model whose accuracy predicts the in crease of the carbonation depth of the concrete in relation to the tensile stress in rebar. (C) 1999 Elsevier Science Ltd. All rights reserved.