Final answer:
The minimum compressive strength for a slab not exposed to weather is typically around 20 MPa or 2900 psi.
Step-by-step explanation:
The minimum compressive strength for a slab not exposed to weather depends on the specific application and the code requirements. However, in general, the minimum specified concrete compressive strength for structural concrete is 20 MPa (megapascals) or 2900 psi (pounds per square inch).
This means that the concrete should have a minimum compressive strength of 20 MPa at 28 days after casting. The compressive strength is a measure of the concrete's ability to withstand compressive loads without failure.
It is important to note that the actual compressive strength required for a particular slab design may vary based on factors such as the anticipated loads, the concrete mix design, and any specific requirements outlined in the building code or project specifications.