Construction Methods and Materials Flashcards
7 cards from real CITB practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Construction Methods and Materials flashcards as text
What is the primary purpose of a vapor barrier in wall construction?
Answer: To prevent moisture migration into insulation and framing
A vapor barrier prevents moisture-laden air from migrating into wall cavities, protecting insulation and framing from condensation damage.
Which type of concrete mix design has the highest water-to-cement ratio?
Answer: Lean concrete used as a mud slab
Lean concrete (mud slab) typically has the highest water-to-cement ratio because strength is not the primary concern — workability and economy are.
In steel frame construction, what is the function of a shear tab connection?
Answer: To connect beams to columns while transferring shear loads
A shear tab is a simple framing connection welded to the column that allows a beam to be bolted to it, transferring vertical shear forces.
What distinguishes engineered lumber products like LVL from dimensional lumber?
Answer: LVL uses veneers bonded under heat and pressure for consistent strength
Laminated Veneer Lumber (LVL) is manufactured by bonding wood veneers with structural adhesives, eliminating natural defects and providing predictable, higher strength.
Which excavation method is most appropriate for installing a large-diameter water main under an active roadway?
Answer: Horizontal directional drilling (HDD)
Horizontal directional drilling installs pipe underground without disturbing the road surface, minimizing traffic disruption and restoration costs.
What is the term for the process of gradually increasing load on a newly constructed post-tensioned concrete slab?
Answer: Propping and de-propping sequence
Post-tensioned slabs require a carefully planned propping and de-propping sequence to gradually transfer loads and allow the concrete to reach design strength.
Galvanized steel fasteners are required when connecting pressure-treated lumber primarily because:
Answer: The preservative chemicals in treated lumber corrode standard steel fasteners
Modern pressure-treated lumber contains chemicals that accelerate corrosion of standard steel fasteners, so hot-dipped galvanized or stainless steel must be used.