Contraction or shrinkage control joints: Install between expansion joints at regular intervals not exceeding 4 m. Construct joints by forming grooves 40 mm deep by 6 mm wide in all exposed surfaces of the concrete kerb and channel. Provide grooves normal to the top surface and square to the alignment of the concrete kerb and channel. Where relevant, locate joints to line up with contraction joints in adjacent structures.
Expansion joints: Provide expansion joints between the concrete kerb and channel and any abutting structures (such as bridges, rigid pavements and concrete slabs), or where directed. Where relevant, locate joints to line up with the expansion joints in adjacent structures. Construct joints by installing 10 mm thick compressible packing for the full width and depth of the concrete kerb and channel. Seal surface of joint with a suitable polyurethane sealant, Thioflex 600 or equivalent.