Shrinkage in hot and arid environments is a major concern, as it often leads to early-age cracking in slabs-on-ground cast under such climatic conditions. The low humidity and high thermal gradient provide significant impetus for the rapid drying of concrete slabs. An experimental program was conducted to monitor the development of strains and cracking in large-scale concrete slabs-on-ground of dimensions 6000 mm × 1100 mm × 200 mm reinforced with nonmetallic FRP bars, exposed to field conditions during the hot summer months. GFRP bars, unlike steel, are immune to corrosion and offer superior durability in aggressive environments, making them a more suitable choice for long-term performance in hot and arid regions. The evolution of shrinkage strain and the formation of cracks were monitored in six slabs reinforced with ribbed and sand-coated glass fiber-reinforced polymer (GFRP) bars, a basalt fiber-reinforced polymer (BFRP) mesh, and conventional ribbed steel bars, all placed on a 100 mm thick layer of lean concrete laid over compacted soil. Nonlinear finite element (FE) simulations of these slabs-on-ground were developed in ABAQUS to replicate the evolution of strain and crack development. The FE model accurately predicted the development of environmentally induced stresses and cracking in the concrete slabs. Numerical parametric studies were then conducted using the validated model to explore the influence of factors such as concrete strength, bar diameter, and slab thickness on the evolution of strains, stresses, and cracking over time.