Abstract: A device for use in expansion joints in ramps, bridges, sidewalks, floors of multi-story car parks and the like having at least one cellular sealing strip made of an elastic material which when installed is supported on two opposite sides of the expansion joint. The strip has a number of planar faces that are at all times alined in a single common plane to form the top side of the sealing strip in every working condition thereof. Thus the top side of the strip is always planar no matter to what extent it is compressed or stretched. The webs forming the walls of the cells converge or diverge in relation to each other.