No. Concrete is capable of enormously greater compressive than tensile
stress. Reinforcing steel is used for tensile strength, which will
have to cope with potentially large stresses.
It will crack, especially thin, large-area slabs. That's why tools are
used to make "parting lines" in slab, on pouring- to locate where the
cracks will be.
Properly dimensioned, supported, and drained below, problems will be
minimized. Quality of materials and workmanship are important,