FORCES DUE TO THERMAL EXPANSION IN CONCRETE

[n62121]

If an infinitely long (theoretically) PCC SLAB-ON-GRADE is rigidly constrained (non-yielding) on the two edges, what would be the buildup in edge forces, in psi, thru a range of delta T (F°)? The slab has no expansion joints either longitudinally nor along the edges. The slab is 5" thick and minimum 3,000 psi compressive strength specified. In this case the slab is twenty five (25) feet wide. In another location it is 28 feet wide. T (F°) varies seasonally between 34°F and 110°F.

 

[ishvaaag]

This can be deduced from the force required to bring the freely expanding slab back to its non elongated status, that is, the restrained one. Calculate elongation for the increment of temperature, then through modulus of deformation (Young) ascertain the restoring force, then the stress.

 

[twinsemi]

You may want to add a few degrees (if the slab is in sunlight) for radiant heating.