DURABILITY PERFORMANCE AND SERVICE LIFE OF CONCRETE STRUCTURES UNDER CORROSION OF STEEL REINFORCEMENT

Author(s): Byung H. Oh, Bong S. Jang and Seung Y. Jang
Paper category: Proceedings
Book title: Proceedings of CONSEC13 Seventh International Conference on Concrete under Severe Conditions - Environment and Loading Volume I
Editor(s): Z.J. Li, W. Sun, C.W. Miao, K.Sakai, O.E. Gjørv, N.Banthia
ISBN: 978-2-35158-124-7
e-ISBN: 978-2-35158-134-6
Publisher: RILEM Publications SARL
Publication year: 2013
Pages: 50-66
Total Pages: 961
Language : English

Abstract: The durability performance and service life of concrete structures have received great attention in recent years. This becomes increasingly important as the number of constructed facilities accumulates with increasing ages. Chloride ingress and thus corrosion of steel reinforcement in concrete may be the most important factor that governs the durability and service life of concrete structures.
In this lecture, a series of research results on the durability and service life of concrete structures under corrosion of steel reinforcement is presented. First, the critical chloride concentration that causes the initiation of steel corrosion in concrete is discussed. This threshold value of chloride concentration for corrosion initiation is one of the most important parameters in determining the service life of concrete structures. The critical chloride concentrations causing active corrosion of steel bars were proposed for various cases through comprehensive tests.
The other important parameter that affects the service life of concrete structures may be the critical corrosion amount to induce the cracking of concrete cover. The corrosion-induced expansion of steel bars causes tensile stresses in concrete around the reinforcing bar and eventually induces cracking through concrete cover. Corrosion tests of steel bar in concrete were conducted and the critical corrosion amounts to induce the cracking of concrete cover were then determined. It is shown from the tests that the concrete strength as well as cover thickness affects greatly the critical corrosion amounts. The quantitative values of critical corrosion have been proposed according to cover thickness and concrete strength.
Another important factor that affects greatly the cracking process of concrete cover and thus service life is the nonuniformity of corrosion around a reinforcing bar. Comprehensive nonlinear analyses have been executed to explore the cracking pressures according to the degree of nonuniform corrosion. The present study indicates that the cracking occurs much earlier in case of nonuniform corrosion, which reduces eventually the service life of concrete structures. Finally, the service life of concrete structures considering above factors is discussed.

Online publication : 2013
Publication type : full_text
Public price (Euros) : 0.00