This study proposes a probability-based carbonation prediction approach for successful monitoring of deteriorating concrete structures. Over the last several decades, a number of researchers have studied the concrete carbonation prediction to estimate the long-term performance of carbonated concrete structures. Recently, probability-based durability analyses have been introduced to precisely estimate the carbonation of concrete structures. Since the carbonation of concrete structures, however, can be affected by material compositions as well as various environmental conditions, it is still a challenge to predict concrete carbonation in the field. In this study, the Fick’s first law and a Bayes’ theorem-based carbonation prediction approach is newly proposed using on-site data, which were obtained over 19 years. In particular, the effects of design parameters such as diffusion coefficient, concentration, absorption quantity of CO2, and the degree of hydration have been thoroughly considered in this study. The proposed probabilistic approach has shown a reliable prediction of concrete carbonation and remaining service life.

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Recently, environmental issues have been raised in offshore bridge constructions, which requires constructing temporary bridges in shallow water levels instead of temporary embankment roads. Therefore, this has significantly increased the amount of trestle required in offshore bridge projects. Due to limitations in using marine equipments to approach shallow waters, the phased forward method needs to be implemented in constructing a trestle in shallow waters. However, depending on the capacity of the crane, the phased forward method restricts the span length of the trestle, which would critically increase the construction period. Therefore, in order to perform offshore bridge projects, more competitive approaches are required to reduce the construction period and the quantity of trestle through optimized designs. This research adopts high strength steel and truss type safety barrier as members to control deflection and propose ways of elongating the span of the trestle. Under the same conditions, the application of SM490 steel and truss type safety barrier enable the trestle span to increase up to 21 m. In addition to considering a trestle at a total length of 1050 m, the proposed approach can reduce the number of spans by 33% and decreasing the quantities of sub-structures and the construction period by approximately 2 months.