Expansion Joints Concrete Slabs Spacing

It is also influenced by the slab dimensions type of concrete and the reinforcing materials being used.

Expansion joints concrete slabs spacing.

Cracks in concrete may occur at the expansion joints due to improper concrete mix or curing. Joint spacing that is greater than 15 feet require the use of load transfer devices dowels or diamond plates. So for a 4 inch thick concrete slab expansion joints should be no more than 8 to 12 feet apart. How to cut joints groover tools cut joints in fresh concrete.

Joint spacing in meters. Maximum joint spacing should be 24 to 36 times the thickness of the slab. When using joint groove for contraction joints the joint should be a minimum depth of thickness of the slab. Make sure joints are cut deep enough.

They need to be at least a quarter of the thickness of the slab. The expansion joint gap depends on the type of slab like floating slab floor vehicle pavement sidewalk or monolithic slab foundation. They should also be placed around structures that go deeper than the concrete slab such as columns or walls. Keyed joints are not recommended for industrial floors.

Saw cut joints should be done within 4 to 12 hours after the concrete has been finished. If you have a 4 inch slab and multiply it by 24 to 32 you will find that your joints should be placed every 96 to 144 inches or 8 to 12 feet if you have a 5 inch slab and multiply it by 24 to 32 you will find that your joints should be placed every 120 to 180 inches or 10 to 15 feet. It is also important to keep slabs as square as possible. A 4 slab should have joints 8 12 feet apart.

Usually expansion joints should be no farther apart than 2 to 3 times in feet the total width of the concrete in inches. Joints should be spaced about 10 feet and a maximum of 15 feet. Longitudinal joint spacing on two lane and multilane concrete pavements typically is about 10 to 13 ft 3 0 to 4 2 m. Transverse joint spacing should not exceed 125 to 150 of the longitudinal joint spacing.

A 4 thick slab should have joints 1 deep. This tool provides an estimate of the maximum allowable joint spacing based on the slab thickness and the subgrade subbase used two of the variables with the most prominent effect on joint spacing requirements. Joint spacing in feet contraction joints may be tooled into the concrete surface at the time of placement. Typically for jointed plain concrete streets the joint spacing should be 24 to 30 times the pavement thickness with a maximum spacing of 15 ft 4 5 m.

Saw cutting cuts joints as soon as the concrete is hard enough that the edges abutting the cut don t chip from the saw blade. For a 100mm slab. Tips for placing concrete expansion joints place joints around 30 times the slab thickness apart. So for a slab which is 100mm thick the joints should be placed.