The mechanism of pressure and thus stress build-up due to corrosion of a reinforcing bar in a reinforced concrete member is a very complex phenomenon because there is a certain pressure-free corrosion strain which has not been explored in the…
The mechanism of pressure and thus stress build-up due to corrosion of a reinforcing bar in a reinforced concrete member is a very complex phenomenon because there is a certain pressure-free corrosion strain which has not been explored in the previous studies. The purpose of the present study is to explore the critical corrosion amount which causes the cracking of concrete cover and also to determine the realistic me- chanical properties of corrosion layer including the pressure-free corrosion strain and the stiffness. To this end, a comprehensive experimental and theoretical study has been conducted. Major test variables include concrete strength and cover thickness. The corrosion products which penetrate into the pores and cracks around the steel bar have been considered in the calculation of expansive pressure due to steel corrosion. A concept of pressure-free strain of corrosion product layer was devised and introduced to explain the relation between the expansive pressure and corrosion strain. The proposed theory shows good correlation with corro- sion test data of reinforced concrete members.