Corrosion measurements on reinforcement in silica fume concrete

Corrosion of reinforcement is a major cause of deterioration of concrete structures. Linear polarisation resistance measurements can be used to test different concrete mixes to predict their performance in protecting the steel in structures. An apparatus to carry out these measurements on concretes containing silica fume has been used at Leeds. When carrying out linear polarisation measurements care must be taken to ensure that the readings are not disrupted by the capacitance of the interface and the resistance of the concrete. In this project a time delay of 30 seconds was used to reduce the effect of the capacitance and the resistance of the concrete was measured separately and subtracted. In order to obtain results in laboratory time scales it is necessary to accelerate the corrosion. In this project the concrete samples were placed in a salt solution and an anodic voltage was applied. The results show that under these conditions the silica fume concretes performed better than the ordinary portland cement control concretes.