Aged highway bridges have become substantially prevalent in recent years. Moreover, combined deterioration, caused by using deicing agents in winter, has led to increased bridge maintenance costs. Accordingly, to extend the service life of bridge decks, this study utilized actual inspection data and major deterioration factors to derive the remaining service life of bridge decks. Based on this study, the following three factors are selected: deicing agent exposure grade, pavement condition state, and surface improvement status. Performance degradation curves were derived for 11 cases that considered the representative three deterioration factors, and the performance degradation of decks was examined for each deterioration factor. Additionally, a process to determine maintenance priorities, using the current condition of highway bridges and the deterioration factors of individual bridges, was proposed. The maintenance demand was predicted based on the end of deck life, which indicated that the demand for deck replacement will sharply increase in 15 years, and that the decks of more than 2000 bridges will reach the end of life in 40 years. Furthermore, this paper proposes a process for prioritizing the maintenance of approximately 9000 highway bridge decks. By applying the prioritization process for bridge deck maintenance to the bridge deck, not only can the life of the bridge deck be extended, but also environmental pollution can be minimized. Additionally, an optimizing design for bridge decks, by considering the remaining life and deterioration factors, can be possible. Therefore, it is expected that the sustainability of the bridge deck can be accomplished.

Prestressed concrete structures are used in various fields as they can reduce the cross-sectional area of members compared with reinforced concrete structures. In addition, the use of high-performance and strength concrete can help reduce weight and achieve excellent durability. Recently, structures have increasingly been constructed using high-performance and strength concrete, and therefore, structural verification is required. Thus, this study experimentally evaluated the structural performance of a long-span bridge deck slab joint, regarded as the weak point of structures. The specimens were designed with a 4 m span for application to cable-stayed bridges. To ensure the required load resistance and serviceability, the specimens comprised of 120 MPa high-performance fiber-reinforced concrete and were prestressed. The deck slabs satisfied all static and fatigue performance as well as serviceability requirements, although they were thinner than typical concrete bridge deck slabs. The study also verified whether the deck slabs were suitable to help implement precast segmental construction methods. Finally, the results confirmed that the structural performance of the developed prestressed concrete (PSC) deck slab was sufficient for the intended bridge application as it achieved a sufficiently large safety factor in the static and fatigue performance tests, relative to the design requirement.

The aberrant winter temperatures resulting from climatic shifts give rise to the formation of imperceptible black ice on road surfaces, posing a risk of accidents. In this study, a carbon nanotube (CNT)-based heating module was fabricated, embedded in a concrete slab, and subjected to a full-scale test in an outdoor environment. Preliminary tests were conducted to scrutinize the thermal behavior of the CNT heating modules applied to the concrete slab, considering the inter-module distance and the concentration of multiwalled carbon nanotubes (MWCNTs) in the concrete perimeter. A full-scale concrete slab was fabricated on the basis of the preliminary test results. Thermal performance analyses of the concrete perimeter were performed according to the MWCNT concentration, the distance between the MWCNT heating modules, and the supply voltage based on a full-scale test conducted in an outdoor environment. The full-scale test results indicated that the maximum temperature variation of the MWCNT heating module embedded concrete slab was 46.8 °C, and its thermal performance varied by 1.9 times depending on the concentration of MWCNTs in the concrete perimeter.