Patent ID: 8870236

Claim:
A method of joining a first pipe section comprising a first keyway that is concave relative to the outer surface of the first pipe section to a second pipe section comprising a second keyway that is concave relative to the inner surface of the second pipe section, the method comprising: inserting the first pipe section into the second pipe section; aligning the first keyway and the second keyway; positioning a first key comprising a first shape memory polymer having a first transition temperature between the first keyway and the second keyway, wherein the key has a length and a cross section perpendicular to the length; heating the first key above the first transition temperature; and reducing the length and expanding the cross section of the first key such that the first shape memory polymer fills a portion of both the first keyway and the second keyway, forming a mechanical inference bond between the first pipe section and the second pipe section, wherein the first or second keyway comprises a plurality of first recesses, the other keyway comprises a second recess, wherein aligning the first keyway and the second keyway comprises aligning two or more of the first recesses with at least a portion of the second recess to form a plurality of paired first and second recesses.