The equations 17 to 19 make clear why nowadays relatively small concrete
slabs are applied in plain concrete pavements, with horizontal dimensions
smaller than about 5 m (roads) or 7.5 m (airports) respectively. For these slab
dimensions the span of the slabs both in the longitudinal (L’) and the
transverse (W’) direction is much smaller than the critical slab length lcrit,
resulting in reduced warping stresses ''
t σ
(equation 19).