19 construction materials made of plastic--namely, waterstops and fittings and splices therefor, keyways, control joints, chamfer strips, rustication strips, paving caps, tilt-up shims, flexible drop chutes, hoppers, radius corner formers, split tubing, rigid tubing, flexible tubing, form liners, moldings, joint formers, joint sealers, column formers, sewer pipe, drain pipe, drain boards, ducts to be embedded in walls or floors, sheets of flexible material, architectural form liners, doweling systems for aligning and installing slip dowels in concrete construction joints comprised of a sleeve and attachment base, and expansion boards, for use in the concrete construction industry