In bridge construction, a method that applies prestressing to steel bars in half-depth precast concrete deck panels—similar to the technique used in steel composite girders—has been designated as a Construction New Technology, drawing industry attention. This technology, developed by bridge specialist JANGHEON Industry Co., Ltd. (CEO Seong-hyeol Seo), utilizes pre-tensioned half-depth precast concrete deck panels connected to I-shaped steel girders with expanded head anchors. The ‘Pre-Deck Method,’ jointly developed with HANMAC Engineering, PTC, SAMAN Corporation, and HALLA Energy & Environment, was designated as Construction New Technology No. 852 by the Ministry of Land, Infrastructure and Transport.

JANGHEON Industry currently holds three Construction New Technologies related to girders, including the DR Girder (No. 582), the Pre-tensioned PSC I-Girder (No. 752), and the segmented Nodular Girder (No. 812), which recorded the highest level of application performance in 2016 and 2017.

Unlike previous technologies focused on girders, this newly designated technology applies prestressing and precast principles to bridge deck panels. By introducing prestressing steel bars into the concrete deck, the method improves durability by applying tensile stress within the concrete.

The Pre-Deck Method follows a similar principle by embedding steel bars in concrete and applying stress after casting to enhance deck durability. However, the method incorporates an additional technology to address a limitation of conventional prestressing. In typical prestressing systems, tensioned steel bars may gradually retract inward during the curing period after concrete casting, resulting in a reduction of prestressing force. To mitigate this issue, the Pre-Deck Method applies anchorage devices at both ends of the steel bars, which are formed with round, enlarged heads. This configuration ensures that even if the bars tend to retract during curing, they are restrained by the anchorage devices, thereby minimizing the loss of prestressing force.

Another advantage of the Pre-Deck Method is that factory fabrication (precasting) is possible. Deck panels with lengths of approximately 2.4 to 3.0 meters and a thickness of 110 mm are prefabricated in a factory and then transported to the site, where they are installed sequentially. This approach shortens the construction period and enhances product quality by reducing defects such as cracking. In addition, the use of nut-type connection bolts minimizes interference between adjacent deck panels, allowing deck-to-deck connections to be performed efficiently on site.

In conventional bridge construction, deck slabs are typically constructed on site through rebar placement, formwork installation, and concrete casting. While precast methods exist, issues such as inward retraction of steel bars during curing can reduce durability. JANGHEON Industry’s Pre-Deck Method addresses these on-site challenges by applying prestressing and precast technologies to deck construction.

Compared to conventional cast-in-place methods, the technology shortens the construction period by approximately 40 days and reduces construction costs by about 14%. It also improves economic efficiency by reducing the amount of reinforcing steel compared to conventional prestressing methods.

The Pre-Deck Method was applied to the Namgye Bridge on Section 1 of the Jeoksong–Jeongok project commissioned by the Seoul Regional Construction Management Administration in 2016. According to project feedback, the method achieved a high level of satisfaction from the client.

A representative from JANGHEON Industry stated that, in addition to reducing construction time and costs, the factory-based production of the Pre-Deck Method helps minimize construction waste and industrial accidents, thereby reducing social costs. The representative added that by enhancing structural stability while maintaining constructability, the technology can be applied not only in Korea but also in overseas construction markets.