A stay-in-place form comprises a plurality of elongated panels connectable to one another in edge-to-edge relationship. The plurality of panels comprises first and second panels connectable to one another in edge-adjacent relationship by a connection which comprises a contact joint. The first panel comprise a longitudinally extending first seal-retaining projection shaped to project outwardly from the outer surface of the first panel at a location spaced apart from a first outer-surface transverse edge of the first panel in a first transverse direction. The second panel comprising a longitudinally extending second seal-retaining projection shaped to project outwardly from the outer surface of the second panel at a location spaced apart from a second outer-surface transverse edge of the second panel in a second transverse direction opposite the first transverse direction. The first and second seal-retaining projections and the outer surfaces of the first and second panels defining at least a portion of a seal-receiving concavity which opens outwardly from the form when the connection is made.