NCARB Structural Systems 2

Question 1

In a reinforced concrete beam, where is the primary tension steel typically located?

Accepted Answer

At the bottom of the beam in a simply supported span

Answer

In a simply supported beam, bending causes tension in the bottom fiber; steel reinforcing bars are placed there because concrete is weak in tension but strong in compression.

Question 2

What is the purpose of 'shear walls' in a building's lateral force resisting system?

Accepted Answer

To resist lateral wind and seismic forces through in-plane shear action

Answer

Shear walls resist horizontal forces by acting as vertical cantilevers, transferring lateral loads from the diaphragm down to the foundation through their in-plane stiffness.

Question 3

A post-tensioned concrete slab differs from conventionally reinforced concrete in what way?

Accepted Answer

Steel tendons are stressed after concrete placement to place the slab in compression

Answer

In post-tensioning, high-strength steel tendons are stressed by jacking after the concrete cures, compressing the slab and counteracting tensile stresses from applied loads.

Question 4

What is a 'transfer beam' or 'transfer slab' in structural design?

Accepted Answer

A heavy structural element that collects loads from columns above and redistributes them to a different column grid below

Answer

Transfer beams redirect column loads when the structural grid changes between floors—common in mixed-use buildings where parking columns don't align with upper floor columns.

Question 5

Which structural material has equal strength in both tension and compression?

Accepted Answer

Steel

Answer

Steel's crystalline structure gives it roughly equal yield strength in tension and compression, making it uniquely efficient for members subject to alternating stresses like seismic loading.

NCARB - National Council of Architectural Registration Boards Practice Test

NCARB - National Council of Architectural Registration Boards Practice Test

NCARB Structural Systems 2