Curling Concrete Floor

Curling is the distortion of a slab into a curved shape by upward or downward bending of the edges.

Curling concrete floor. Curling of concrete slabs. As a new concrete floor dries during the first year surface tension caused by this drying of the concrete creates shrinkage and more specifically a lifting or curling of the floor at all floor joints. Written by ramon planas masip. The occurrence is primarily due to differences in moisture and or temperature between the top and bottom surfaces of a concrete slab.

If the total curl is less than 1 4 inch or curling occurs primarily in low traffic areas or under storage racks the owner can often live with it provided that cracking isn t excessive. The best time to pour concrete is when temperatures are expected to remain above 50 degrees for five to seven days but plans can go awry with the arrival of. Curling is the distortion of a slab into a curved shape by upward or downward bending of the edges. Reinforcing steel placed near the top surface of the slab can help restrain curling.

Tolerance floor covering conundrum concrete international july 2003 includes two examples of measured floor flatness and levelness that decrease by as much as 50 in a year due to curling. Don t let new concrete get too cold. Curling in concrete floors causes consequences and solutions. Both the canadian standards association csa and the american concrete institute aci recognize that control of curling is a designer responsibility.

The american concrete institute. 09 january 2019 posted in concrete placing inforce fibre slab design fibre reinforcing technical information. Founded in 1904 and headquartered in farmington hills michigan usa the american concrete institute is a leading authority and resource worldwide for the development dissemination and adoption of its consensus based standards technical resources educational programs and proven expertise for individuals and organizations involved in concrete design. Placing 4 bars on 18 inch centers both ways and chairing the bars to keep them within an inch of the surface has been suggested see controlling curling and cracking in floors to receive coverings concrete construction july 1998 pp.

This occurs primarily due to differences in moisture and or temperature between the top and bottom surfaces of a concrete slab. When concrete slabs on grade curl the curling sometimes has little effect on floor performance. Data from floor slabs indicates that tolerances losses from curling can result in up to a 50 reduction in tolerances that were originally. Page 4 of 6 curling of concrete slabs if the curling had not been highlighted by the cracked brickwork joints it would probably not have been evident as the extent of curling is within typical floor construction tolerances for residential buildings.