RB modular expansion joint consists of edge profile steel, lamella beam, joist beam, control box, rubber seal profile, sliding bearing and anchor rebar. The expansion joint with movement capacity less than 120 mm is composed of two edge beams and a rubber seal. For those of 160 mm or above, increasing number of lamella beams are needed. One lamella beam allows the expansion demand increased by every 80 mm. The range of movements is determined by the operational range of the sealing profile. For instance, if the specified operational range of a sealing profile is 80mm, Modular Joint has three sealing profiles (two lamella beams) will allow a movement range of 3 x 80 = 240mm. When the expansion demand increased by every 80mm, one more lamella beam is needed.