The present disclosure concerns a preform for a curved composite stiffener for an axisymmetric part such as a shroud, including at least one web and at least one flange curved about an axis of revolution of the preform and defining a substantially “T” or an “I” shaped section. In one form, the preform includes a web and a flange, wherein the web includes a plurality of warp yarns circumferentially oriented relative to the axis of revolution of the preform, and a plurality of weft yarns oriented radially relative to said axis, and the flange includes a plurality of warp yarns circumferentially oriented relative to the axis of revolution of the preform, and a plurality of weft yarns substantially parallel to said axis.