The correct answer is: A. It supports live loads in both directions.
A two-way slab is a type of concrete slab that is supported by columns at both ends. It is designed to carry loads in both the longitudinal and transverse directions. This type of slab is often used in buildings with open floor plans, as it allows for greater flexibility in the layout of the space.
The main advantage of a two-way slab is that it is more efficient in terms of material usage than a one-way slab. This is because the load is distributed more evenly across the slab, which means that less material is required to support the load.
However, two-way slabs are also more complex to design and construct than one-way slabs. This is because the loads must be carefully calculated to ensure that the slab is not overloaded. Additionally, two-way slabs require more reinforcement than one-way slabs.
Overall, two-way slabs are a versatile and efficient type of concrete slab that can be used in a variety of applications. They are particularly well-suited for buildings with open floor plans, as they allow for greater flexibility in the layout of the space.
Here is a brief explanation of each option:
- Option A: It supports live loads in both directions. This is the correct answer, as a two-way slab is designed to carry loads in both the longitudinal and transverse directions.
- Option B: The ratio of spans in two directions is less than 2. This is not necessarily the case, as two-way slabs can be designed with any ratio of spans.
- Option C: The slab is continuous over two supports. This is not necessarily the case, as two-way slabs can be designed to be either continuous or discontinuous over supports.
- Option D: The slab is discontinuous at edges. This is not necessarily the case, as two-way slabs can be designed to be either continuous or discontinuous at edges.