Aluminium body structural expansion joints with synthetic rubber insert. Designed to bear structural movements of large sized buildings or compounds of buildings. They are installed over the spaces existing between two semi-detached parts of a building of smaller entity or between different beam bays. They can connect and close these inter-spaces adjusting themselves up-wards, downwards and even transversally, according to the shrinkage-settlement movements of the whole building, either cyclic or permanent. Within the flooring bays frame created with the structural joints, a further surface subdivision with a suitable pattern of movement / expansion joints should be always provided for.