A device and method for assembling two structural elements made from a composite material is provided. The device includes two cylindrical flanged receptacles, each pierced by an aperture perpendicular to the axis of the cylinder, and a shaft that can be introduced into said apertures. The device also includes bearing means, which bear on the interior surfaces of the cylindrical receptacles and can maintain tension in the shaft when the shaft extends through the apertures in the two receptacles. The device includes means of placing the shaft under tension.