DAYFREE

POINT

• Deck replacement possible with single-lane nighttime closures

  DAYFREE overview video

  Conventional bridge deck replacement requires multiple steps—removal of the old deck, steel girder surface cleaning, installation of the new deck, concrete placement at joints, waterproofing, and paving—often necessitating continuous lane closures both day and night over extended periods.
  DAYFREE is a new construction method that enables deck replacement by closing just one lane at night when traffic volume is low. By utilizing specialized equipment, deck jointing techniques, and a temporary deck panel system designed for constrained space and time, the method allows for full traffic flow during the day.

• Mobile deck slab installation machine “Highway Strider”

  Highway Strider animation

  Developed by Obayashi, this deck slab installation machine operates within a single-lane closure zone. After being transported to the installation site by a trailer, it extends its legs for a lifting position by itself, enabling quick setup and removal.

• “Slim NEO Plate” joint method enables daytime traffic reopening

  

  To reopen lanes to traffic, concrete at the deck joints must be filled and hardened—but there isn’t enough time for curing during daytime reopenings. To solve this, precast plates made of ultra-high-strength fiber-reinforced concrete (SLIM-Crete) are installed at the joints. These high-strength plates can withstand traffic loads, making daytime traffic reopening possible. Later, SLIM-Crete is pressure-injected beneath the precast plates to permanently join the deck sections.

• “Temporary Deck Panel System” enables splitting of work processes

  

  It is not feasible to complete all necessary processes—removing the old deck, cleaning steel girders, installing the new deck, placing joint concrete, and applying waterproofing and paving—within a single night. To address this, the work is split into two nights: night 1 for deck removal and girder cleaning, and night 2 for deck installation and paving. During the daytime opening between the two nights, a steel temporary deck panel system is used to allow traffic to pass.