Screed Rail
A screed rail comprises first and second elongate plate members arranged in face-to-face configuration, the first plate member being attached to leg members by height-adjustable lock means and the second plate member being attached to the first plate member by frangible joining means with the upper edges of the plate members in registration. The second plate member is attached only to the first plate member and the first plate member is attached to the leg members and by independent frangible connections to the second plate member whereby the plate members can separate laterally as the concrete cures without the attachment of the leg members inhibiting movement of the second plate member relative to the first.
1 . A screed rail comprising first and second elongate plate members arranged in face-to-face configuration, the first plate member being attached to leg members by height-adjustable lock means and the second plate member being attached to the first plate member by frangible joining means with the upper edges of the plate members in registration.
2 . A screed rail according to claim 1 , in which the second plate member is the same length as the first plate member but is shallower in depth, the lower edge of the second plate member being disposed above the lock means which attach the leg members to the first plate member.
3 . A screed rail according to claim 1 , in which the height-adjustable lock means comprise vertical slotted apertures formed in the first plate member and through which the lock means pass, the second plate member being out of contact with the lock means.
4 . A screed rail according to claim 1 , in which the plates include means for accommodating laterally-disposed dowels or plates for providing load transfer between adjacent slabs.
5 . A screed rail according to claim 4 , in which the plates are in the form of diamonds or trapezoidal plates and the sleeves are adapted to accommodate sideways movement of the plates as well as horizontal movement orthogonal to the screed rail.
6 . A screed rail according to claim 1 , in which the plate members are provided or formed with at least the upper edges being turned over to define a substantially horizontal (in use) planar upper face and a return or downwardly-extending lip.
7 . A screed rail according to claim 6 , in which the horizontal upper-facing surfaces are formed with apertures.
8 . A screed rail according to claim 7 , in which the apertures extend partially to the vertical or main part of the member and/or to the lip.
9 . A screed rail according to claim 1 , in which the plate members have a plain straight upper edge, the first plate member being formed with at least one groove or channel formation extending from one face.
10 . A screed rail according to claim 9 , in which the second plate member is formed, along its lower part, with a laterally-extending skirt region for embedding in the concrete.
11 . A screed rail according to claim 10 , in which the skirt has an array of spaced-apart apertures formed therein for additional keying with the concrete.
12 . A screed rail according to claim 1 , in which the first plate and second plate members are joined together in a longitudinally offset relationship.
13 . (canceled)