Where reinforcement is not desired, slab lengths must be chosen so that intermediate
transverse cracks are eliminated. The most current theory used to determine allowable
slab lengths involves a very old concept developed by Dr. H. M. Westergaard.
Westergaard defined a constant called the radius of relative stiffness as an algorithm
that relates the modulus of subgrade reaction to the flexural stiffness of the slab.
Research indicates that cracking can be expected when the ratio between the slab length