Papers by Author: In Seok Yoon

Abstract: The purpose of this study is to establish an analytical formulation for determination of the critical chloride content in concrete. In this study, factors affecting the critical chloride content such as mix proportion, environment, chemical evolution of pore solution with time, carbonation and so on are taken into account. The numerical simulation program of cementitious materials, HYMOSTRUC was utilized for the construction of the formulation. This was expressed as a free chloride content in a mass unit of concrete as a time function.

Abstract: This study is focused on examining the effect of critical crack width in combination with crack depth on chloride penetration into concrete. Because concrete structures have to meet a minimum service-life, critical crack width has become an important parameter. Specimens with different crack width / crack length have been subjected to rapid chloride migration testing (RCM). The results of this study show a critical crack width of about 0.012 mm. Cracks smaller than this critical crack width are considered not to have a significant influence on the rate of chloride transport inwards, while chloride penetration does proceed faster above this critical crack width.

Abstract: It is a prerequisite to formulate material parameters affecting chloride penetration into concrete. This paper is focused on defining intrinsic parameters of concrete, linking a theoretical solution for durability design in submerged concrete under marine environment. Material parameters, such as surface chloride content, chloride diffusivity, critical threshold critical content, chloride binding capacity are formulated.

Abstract: In most studies, deterioration of concrete due to carbonation or chloride penetration is investigated separately. However, the deterioration of concrete is normally caused by the combination. The purpose of this study is to investigate the interaction between carbonation and chloride penetration and their effects on concrete. This was examined experimentally under various boundary conditions. For concrete under the double condition, the risk of deterioration due to carbonation was not severe. However, it was found that the carbonation of concrete could significantly accelerate chloride penetration. As a result, chloride penetration in combination with carbonation can cause harmful deterioration of concrete.