Concrete Flashcards
(23 cards)
- Concrete is a mixture of
a. Cement, water and additives
b. Cement, sand and water
c. Cement, grave, sand, water and additives
d. Cement, sand and additives
C
- Vertical lines on the face of a concrete structure would indicate
a. Pre- stressing
b. Slip- forming
c. Shuttering
d. Cable tracks
B
- Concrete corrosion refers to
a. Disintegration of the concrete matrix
b. The erosion of the corner edges
c. The corrosion of the rebar through loss of cover
d. Loss of cover
C
- Steel reinforcement must have adequate cover
a. To protect from sea water penetration
b. To protect from accidental damage
c. To protect from spalling
d. All of the above
A
- A wide crack is a crack with a width of
a. 0-1mm
b. 1-2mm
c. More than 2mm
d. Less than 2mm
C
- Salts appearing on the surface of the concrete have been washed out from a crack are called
a. Exudation
b. Incrustation
c. Spalling
d. Carbonation
A
- If concrete is poured from heights greater than 2m what’s like to occur
a. Slipforming
b. Deterioration
c. Honey combing
d. Jointing
C
- The gritty joint formed by insufficient surface wetting in hot conditions
a. A cold joint
b. A dry joint
c. A panel joint
d. A construction joint
A
- Which of the following is not likely to cause discolouration
a. Additives
b. Steam curing
c. Rust
d. Mound oil
B
- Concrete is designed to protect the rebar a situation called passivation, what PH level does the concrete need to be able to achieve this:
a. 4
b. 8
c. 12
d. 14
C
- Which of the following statements about concrete is true
a. It’s impermeable so protecting the rebar
b. It’s totally porous but protect the rebar through passivation
c. It’s porous but if cover is sufficient water will not penetrate
d. It’s porous but the rebar can not rust as no oxygen is present
C
- What should she-bolts indicate:
a. Pre-stressing cables
b. Fixing points
c. Shoddy workmanship
d. Shuttered construction
D
- A jarlan wall is
a. A slip-formed wall
b. A perforated wave wall
c. A caisson wall
d. A shuttered wall
B
14.which of the following are considered to be important features
a. Loss of cover
b. Surface discolouration
c. Fine cracks
d. All of the above
A
- Which of the following are considered to be unimportant features
a. Stains on the concrete
b. Surface crazing
c. Honeycombing
d. Spalling
B
- Pre-stressed tendons are installed to:
a. Prevent the concrete falling apart
b. To impart tension
c. To impart compression
d. To keep the shuttering in place
C
- Construction joint are
a. Planned joints during construction
b. Joints are wet concrete has accidentally been poured on dry concrete
c. Unplanned steps during construction
d. Marks left by the shuttering
A
- Excessive vibration during construction will cause
a. Bleeding channels
b. Sand streaks
c. Water pockets
d. Stratification
D
- Loss of cover is particularly important because
a. The wall thickness is decreased
b. Corrosion may take place
c. It may not be possible to find it again
d. It allows wind and rain to get in
B
- The strongest form of concrete is produced by
a. Slipform shuttering
b. Board shuttering
c. Pre-cast sections
d. Integration
A
- The underside of a concrete beam is
a. Soffit
b. Splay
c. Overhang
d. Underside
A
- Concrete in service defects are
a. A fatigue crack
b. Hot tears
c. Diffraction mottling
d. None of the above
A
- What’s the most common method of inspection for concrete
a. MPI
b. UT metering
c. Visual inspection
d. Radiography
C
