CTQP Structures Inspection 2 — Questions and Answers
Question 1: What is the purpose of 'concrete cover' requirements for reinforcing steel in bridge members?
- To increase the section modulus of the member
- To protect reinforcing steel from corrosion by providing adequate depth of concrete (Correct answer)
- To ensure the member can achieve the required moment capacity
- To reduce the weight of the finished bridge member
Correct answer: To protect reinforcing steel from corrosion by providing adequate depth of concrete
Concrete cover protects reinforcing steel from chloride penetration and corrosion, which is especially critical in Florida's coastal and marine environments.
Question 2: What is 'spiral reinforcement' in a bridge column (pile or column pier)?
- Horizontal circular hoops spaced along the column height to provide confinement and shear resistance (Correct answer)
- Diagonal reinforcing steel placed at 45 degrees to resist torsion
- Vertical bars placed in a spiral pattern to resist buckling
- Reinforcing placed in the column footing to prevent punching shear
Correct answer: Horizontal circular hoops spaced along the column height to provide confinement and shear resistance
Spiral reinforcement consists of closely spaced circular ties wound helically around the column core, providing confinement, ductility, and resistance to shear and seismic forces.
Question 3: What is the inspector's role during placement of precast bridge girders?
- Only to verify the girder identification marks match the plans
- To verify girder placement location, bearing pad installation, and girder alignment and plumbness (Correct answer)
- To operate the crane during erection
- To approve the rigging plan before any lifts begin
Correct answer: To verify girder placement location, bearing pad installation, and girder alignment and plumbness
During girder erection, the inspector verifies that girders are placed at the correct location, bearing pads are properly installed, and girders are plumb and correctly spaced before any connections are made.
Question 4: What is 'deck drainage' in bridge construction and why is it critical?
- Drainage of stormwater from the approach roadway to the bridge
- The system of scuppers, drains, and downspouts that removes water from the bridge deck surface (Correct answer)
- Drainage of water from inside box girders
- The drainage layer installed beneath the bridge deck waterproofing
Correct answer: The system of scuppers, drains, and downspouts that removes water from the bridge deck surface
Bridge deck drainage removes water quickly from the deck surface through scuppers and downspouts to prevent ponding, reduce hydroplaning risk, and minimize chloride exposure to the deck.
Question 5: What is 'camber' in a prestressed concrete bridge girder?
- The horizontal curvature of the girder to match roadway alignment
- The upward deflection built into the girder by prestress forces before any applied loads (Correct answer)
- The downward slope of the girder to provide deck drainage
- The lateral bow of the girder that must be corrected before erection
Correct answer: The upward deflection built into the girder by prestress forces before any applied loads
Camber is the upward bow in a prestressed girder caused by the eccentric prestressing force; it partially or fully offsets dead load deflection when the girder is loaded.
Question 6: What type of inspection is performed on welds in a steel bridge structure?
- Visual inspection only
- Visual inspection supplemented by nondestructive testing (NDT) such as magnetic particle, ultrasonic, or dye penetrant testing (Correct answer)
- Destructive core sampling of the weld
- Chemical analysis of the weld metal
Correct answer: Visual inspection supplemented by nondestructive testing (NDT) such as magnetic particle, ultrasonic, or dye penetrant testing
Bridge welds require visual inspection for workmanship, plus nondestructive testing (NDT) methods such as magnetic particle testing or ultrasonic testing to detect internal defects not visible to the eye.
CTQP Structures Inspection 2
What is the purpose of 'concrete cover' requirements for reinforcing steel in bridge members?