Determination of Specific Electrical Resistance and Carbonation Depth of Concrete in Reinforced Concrete Elements

摘要

The carbonation of concrete and chloride ions in it affect on the durability and proper functioning of reinforced concrete structures. They contribute to the faster corrosion of the reinforcement. In this paper is experimentally investigated the actual state of 12 reinforced concrete beams at age of 1926 days from their preparation. They are loaded on bending till the yielding of the longitudinal reinforcement or till loading stage before the yielding, corresponding to a maximum crack width of 0.3 mm. Then the reinforced concrete elements were indoors for two years and after that subjected to external atmospheric influences for three years. For assessing the state of the beams destructive and non-destructive methods for control have been used. The chloride ion penetration is determined by measuring the surface specific electrical resistance of the concrete with a 4-point Wenner probe with instrument ResiPod Family of the company Proceq. The carbonation depth of concrete is determined on concrete cores that have been taken from the reinforced concrete beams. The cores were treated with a solution of 1% phenolphthalein in alcohol according to EN 14630: 2007.