Abstract: A joint sealing member such as may be used in civil engineering works for providing a watertight seal between joint members is disclosed. In one embodiment, the sealing member takes the form of a band-like member constituted by a central portion made of a water expansible material which expands upon absorbing water and lateral nonexpansible portions made of a rubber which does not change in volume when in contact with water. The thickness of the central portion is greater than that of the lateral portions. In another embodiment, the joint member takes the form of a belt-like base plate made of a water expansible material having one or more longitudinally extending rib-like ridge portions formed on one side thereof.

Abstract: The invention relates to a seal (1) for a joint comprising a cylindrical inner core layer (2) made of a water-unexpansible flexible material and having an internal opening (2a), and an outer coating layer (3) which is made of a water-expansible rubber. The outer coating layer (3) coats the inner core layer (2) and has penetrating openings (4) in the form of slits, pinholes or the like. The penetrating openings (4) extend to penetrating openings in the inner core layer (2) and communicate with the internal opening (2a) through the penetrating openings of the inner core layer (2).