What is isolation joint in concrete?
An isolation joint is a separation between adjacent sections of a concrete structure to allow relative movement in three directions and through which all of the bonded reinforcement is interrupted.
What are the three types of concrete joints?
There are three types of joints: Contraction Joints, Construction Joints and Isolation joints. The most common are contraction joints which control cracks which are caused by restrained shrinkage, loads and other stresses. The joint depth should be AT LEAST ¼ of the slab thickness.
Where are isolation joints used?
Isolation joints include full-depth, full-width joints found at bridge abutments, intersections, or between old and new pavements. The term isolation joint also applies to joints around in-pavement structures such as drainage inlets, manholes, footings, and lighting structures.
What is the difference between expansion joint and isolation joint?
Isolation joints separate a concrete slab from something else like a wall, a post, or a pipe. It can also damage pipes and drains. Expansion Joints. While isolation joints are recommended both inside and out, expansion joints are designed primarily for outdoor situations where weather extremes can add to slab movement.
Why do we need isolation joint?
Isolation joints allow for anticipated differential horizontal and vertical movements between pavements and structures. Their purpose is to allow movement without damaging adjacent structures.
What goes between 2 slabs of concrete?
Trim-A-Slab is made from a rubber-like material that flexes and holds itself into the gap between concrete slabs.
What are keyways in concrete?
keyway
- a slot in a lock for receiving and guiding the key.
- (in poured-concrete construction) a longitudinal groove in a footing, or in a pour that has set, providing a key for newly poured concrete.
- a depression or slot carved into rock to provide a bond or anchorage for a structure, as a dam.
What is a longitudinal joint in concrete?
A longitudinal joint consists of a tie bar placed at the mid-depth of a concrete pavement and it is not intended for joint lateral movement. When uneven settlement occurs, the tie bars in longitudinal joints perform as hinges (Ministry of Transport (1955)) which allow for the settlement of concrete carriageway.
Do you need joints in concrete?
Concrete expands and contracts with changes in temperature and moisture. If not properly controlled, cracks can begin to appear. Placement of concrete control joints and expansion joints are crucial when designing and pouring concrete slabs and sidewalks.
What is an isolation slab?
An isolation joint is a separation of an existing concrete slab from a new concrete slab or wall. A piece of expansion joint (usually ½” wide and made of cork or recycled fiber material) is placed against the existing concrete slab and when the new concrete slab is poured, this expansion joint separates the two slabs.
Where do Isolation joints go on a slab?
Isolation joint material should go all the way through the slab, starting at the subbase, but should not extend above the top. For a cleaner looking isolation joint, the top part of the preformed filler can be cut off and the space filled with elastomeric sealant.
What kind of sealant do you use on Isolation joints?
For a cleaner looking isolation joint, the top part of the preformed filler can be cut off and the space filled with elastomeric sealant. Some proprietary joints come with removable caps to form this sealant reservoir.
What causes blowups in Isolation joints in concrete?
Blowups, from expansion of concrete due to hot weather and sun, are more commonly caused by contraction joints that are not sealed and that then fill up with noncompressible materials (rocks, dirt). They can also be due to very long unjointed sections. Polyethylene foam isolation joint material comes in various colors. C 2 Products
Can a wooden column be isolated from a concrete slab?
Here are a few things to consider with isolation joints: Even wooden columns should be isolated from the slab. Very long unjointed sections can expand enough from the hot sun to cause blowups, but this is rare. Polyethylene foam isolation joint material comes in various colors.