A connector (1) for joining two pipe sections (2) and (3) making up a riser includes a male tubular element (4) and a female tubular element (5) which fit into each other and have an axial shoulder (8) or (9). Locking ring (10), mounted mobile in rotation on the male element (4) or the female element (5), includes studs which cooperate with the studs of female element (5) or the male element (4) so as to form a bayonet connection. The male (4) and female (5) tubular elements include teeth and cavities, the teeth of one of the elements fitting into the cavities of the other element so as to lock in rotation one of the elements in relation to the other.