Movement joint

A free movement, arris protection, construction joint for dividing a concrete during pouring of slabs on opposite sides of the joint, the joint having a top-to-bottom depth in the joint's use orientation, giving depth to the slabs, the joint comprising:

• a pair of elongate fabrications of steel one for each side of the joint, the pair of elongate fabrications each having:
• a top and a bottom edge separated by the top-to-bottom depth;
• and
• means for frangibly fastening the pair of elongate fabrications together, in metal-to-metal contact prior to and during pouring of the slabs;
• and
• the pair of elongate fabrications including:
• means for anchoring the pair of elongate fabrications in the slabs on opposite sides of the joint;
• two arris protection members, one in each elongate fabrication of the pair of elongate fabrications for protecting an arris of one of the slabs at one of the opposite sides of the joint;
• the two arris protection members:
• being complementarily formed along a length of the joint with a regular wave shape, with each arris protection member extending with a regular wave shape across a mid-plane of the joint from one side to the other side and back again at successive positions along the joint at least whilst the pair of elongate fabrications remain frangibly connected;
• having a width transverse the length of the joint giving the joint the top-to-bottom depth, the width being suitable for the depth of load bearing slabs;
• being single pieces configured to act together as a divider for dividing the slabs with the top edges flush with each other and with the bottom edges flush with each other;
• and
• the regular wave shape extending throughout the depth of the arris protection members, including each arris protection member, whereby on pouring, the slabs are formed with interdigitated concrete fingers edged at the slabs' arrises by the arris protection members and extending through the entire depth of the slabs;
• and
• dowels, which are welded-in-place extending outwards of the mid-plane of the joint on one side of the joint and having sleeves extending on the dowels on the other side of the joint for transferring a vertical load between the slabs on opposite sides of the joint, wherein:
• the means for anchoring comprises continuous welded-on members, the welding being at the furthest extent of the arris-protection members from the mid-plane of the joint, that is at lateral wave peaks;
• the dowels being welded to the arris-protection member on the one side of the joint and to the continuous welded-on anchor members at this one side of the joint;
• whereby after casting and shrinkage of the slabs, the free movement, arris protection, construction joint has:
• each of the arris protection members abutting one of the slabs, with a pair of arris protection members being separated by shrinkage of the slabs, with the frangible fastening together of the arris protection members being broken;
• and
• each dowel remaining within a respective one of the sleeves on the other side of the joint.