NCIDQ IDFX Practice Exam

What is a key characteristic of a concrete beam and girder system?

1. Supports electrical installations directly

2. Has no beams and depends on columns alone

3. Slab is supported by intermediate beams

4. Involves only lightweight materials

The correct answer is: Slab is supported by intermediate beams

A concrete beam and girder system is characterized primarily by its structural setup where slabs are supported by intermediate beams. This system typically consists of beams that span between columns, providing support for the floor slabs above. The use of these beams allows for efficient load distribution and helps in managing larger spans, which can accommodate various architectural designs. In this context, the slab acts as a flat surface upon which life loads and dead loads are applied, transferring those loads to the intermediate beams. The beams then carry these loads down to the columns. This is essential in modern construction where space and flexibility are critical components of building design. The other choices do not reflect the fundamental nature of a concrete beam and girder system. Supporting electrical installations directly is not a structural characteristic, and stating that there are no beams relies solely on columns is inaccurate as that describes a different type of system, like a flat slab design. Lastly, claiming the system involves only lightweight materials misrepresents the typical construction materials where concrete, a heavy material, plays a vital role in providing strength and durability.