タイトルまたは説明

Waterproof Membrane Finger Joint (WMF)



Since the U-shaped waterproof sheet of existing finger joint has a problem that foreignmatter entry which causes frequent breakage.



To resolve such problem, there is a finger plate at the upper expansion joint(bridge face) and waterproof support plate at the lower part, and multi-porous waterproof seal is assembled between them to provide the same bridge surface waterproofing as the rail type expansion joint.

1. Problems of existing finger joints

• Loss of waterproofing sheet and waterproofing function due to accumulated load of

  foreign matters accumulated in finger gap

• Corrosion of waterproof sheet due to chemical reaction caused by foreign matters,

  shortening the durability life of bridges

• When the waterproof material is broken, there is no maintenance method

• Periodic cleaning is needed to remove foreign matters

• Increased cost of construction and maintenance due to installation of separate stormwatergutter

2. Features of waterproof membrane finger joint

• No separate drainage facility required in the same way as rail joint.

• Unlike conventional finger joints, there is no foreign matter entry between clearances,eliminating the need for separate maintenance

• Finger plate and waterproof material support plate are divided and assembled, increasingthe ease of installation and maintenance

• Improved durability of bridges by completely eliminating the problem of waterproofingmaterial damage caused by accumulated foreign matter

• Applicable to all sizes, regardless of the amount of expansion

• The lower elastic member support plate adopted corrosion resistant material