Structural Slab Joints? What are they? and How can we draw or model them in Revit Software. In this video I show you a couple of ways to do this.
Examples of slab joints in structural drafting:
- Control Joints (C.J.) – These can be sawn, tooled, construction, expansion and key joints as the control the concrete shrinkage as it cures. Typically for slabs on ground / grade.
- Construction Joints (C.J.) – These are temporary joints between two concrete pours, but with reinforcement between which permanently stitches the pours together as the concrete sets.
- Expansion Joints (E.J.)
- Isolation Joints (I.J.)
- Key Joint (K.J.)
- Sawn Joint (S.J.) – These are for slabs on ground, typically they are sawn to 1/3 the depth of the slab when the slab is still “green” or not fully set yet. They are for shrinkage control as the concrete dries out after pour.
- Tooled Joint (T.J.) – Similar in purpose to the sawn joint, but they are manually placed in the wet concrete after pour.
- Temporary Movement Joint (T.M.J.) – In post tensioned slabs the strands/tendons compress the slab. For the first 56 days of a post tension concrete pour controlling this is important for big concrete slab areas, or they will lock together and create undesirable cracking. After 56 days these joints are grout filled and become locked in place, hence they are only temporary.
- Permanent Movement Joint (P.M.J.) – Use for large structures to allow permanent movement between distinct areas.