Swing loop joints
1. Overview
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The highway bridges built during Japan’s period of high economic growth are aging, which means an increasing amount of bridge deck slab renewal work is needed. Loop joints are typically used when replacing existing reinforced concrete floor slabs with precast PC floor slabs; however, because the minimum floor slab thickness is determined by the minimum bending diameter of the loop portion of the loop joint, this creates a problem in that it increases the floor slab thickness, which tends to increase the dead weight load.
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With the swing loop joint method of joint construction, the loop rebar is arranged diagonally during installation of the loop joints in the precast PC floor slabs, thereby reducing floor slab thickness.
Precast PC floor slab thickness can be made thinner than the minimum floor slab thickness determined by the minimum bending diameter.
2. Key Features
- Swing loop joints have the same yield strength and fatigue resistance as loop joints.
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By arranging the loop rebar diagonally, the thickness of the precast PC floor slab can be made thinner.
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Because no special rebar processing is performed for the loop rebar, the production costs can be kept lower than those for joints requiring special processing and materials.
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It is possible to perform partial replacement.
3. Catalogs, Technical Reports, Associations, Other
4. NETIS Registration / Patent
- Trademark registration: No. 6084382 (utility model)