Reinforced Concrete Design Flashcards
6 cards from real BCE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Reinforced Concrete Design flashcards as text
The effective flange width in a T-beam is limited to account for which phenomenon?
Answer: Shear lag, where stresses are not uniform across wide flanges
Shear lag causes non-uniform stress distribution across wide flanges; ACI limits the effective flange width to the region where flange stress is significant.
For a doubly reinforced beam, the compression steel is included in the design primarily to:
Answer: Increase moment capacity when singly reinforced section is insufficient or reduce long-term deflection
Compression steel is added when the required moment exceeds the capacity of a singly reinforced section (ρmax), or to reduce long-term creep deflections.
Under ACI 318, which factor primarily determines whether a section is tension-controlled or compression-controlled?
Answer: The net tensile strain in the extreme tensile steel at nominal strength
ACI 318 classifies sections by the net tensile strain εt: tension-controlled when εt ≥ 0.005, compression-controlled when εt ≤ εy, and transition in between.
Beam deflection calculations for reinforced concrete use which moment of inertia per ACI 318?
Answer: Effective moment of inertia (Ie) interpolating between Ig and Icr
ACI 318 uses the Branson formula for effective moment of inertia Ie, which interpolates between gross (Ig) and cracked (Icr) section values based on the ratio of cracking to applied moment.
In the equivalent frame method for two-way slab design, what is an 'equivalent frame'?
Answer: A planar frame formed by a row of columns and the slab strips between panel centerlines in each direction
The equivalent frame method models the 3D slab-column system as a series of 2D planar frames, each consisting of columns and the full slab width between panel centerlines.
What is the purpose of a construction joint in a concrete structure?
Answer: To provide a planned location where concrete placement is stopped and resumed, requiring proper design to transfer forces
Construction joints are pre-planned stoppage points in concrete placement designed with roughened surfaces, dowels, or keys to ensure adequate shear and moment transfer across the joint.