Construction Materials & Methods Flashcards
7 cards from real CBP 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 Materials & Methods flashcards as text
What is the primary purpose of a 'bond beam' in concrete masonry unit (CMU) construction?
Answer: To distribute concentrated loads and tie the masonry wall together horizontally with reinforced concrete
A bond beam is a horizontal course of CMU cells filled with concrete and steel reinforcing bars, used to distribute loads and provide continuity and tensile resistance across the wall.
Which insulation material has the highest R-value per inch of thickness?
Answer: Closed-cell spray polyurethane foam (SPF)
Closed-cell spray polyurethane foam achieves approximately R-6 to R-7 per inch, the highest of common insulation materials, compared to R-3.5 for fiberglass, R-5 for XPS, and R-3.7 for mineral wool.
In foundation construction, what is the primary purpose of 'cleanouts' at the bottom of a CMU or poured concrete foundation wall?
Answer: To provide inspection and debris removal access at the base of reinforced masonry cells before grouting
Cleanouts are temporary openings at the base of CMU cells that allow workers to remove mortar droppings and debris before grouting, ensuring proper bond between grout and reinforcing steel.
What is the correct installation sequence for a drainage plane (weather-resistive barrier) and window flashing in a wood-framed wall?
Answer: Install sill flashing first, then WRB lapped over the sill flashing, then jamb flashings, then window unit
Proper installation requires sill pan flashing first, then the WRB lapped over the sill, then jamb flashings, then the window unit, creating a shingle-lap drainage path that directs water away from the opening.
What does the 'U-factor' of a window assembly measure?
Answer: The rate of non-solar heat transfer through the entire window assembly
The U-factor measures the rate of heat transfer (conduction, convection, and radiation) through a window assembly; lower U-factors indicate better insulating performance.
Which method of concrete placement is most appropriate when pouring a continuous strip footing that is 12 inches wide and 24 inches deep?
Answer: Pneumatic placement via concrete pump truck for speed and consolidation
A pump truck allows controlled placement of concrete in a confined deep footing without segregation, and the hose can be positioned at the bottom of the form to minimize drop height and aggregate separation.
What is the primary structural role of steel reinforcing bars (rebar) in reinforced concrete construction?
Answer: To resist tensile forces in zones where concrete alone is insufficient
Concrete is strong in compression but weak in tension; steel reinforcing bars are placed in the tensile zones of structural members to resist the tensile stresses that concrete cannot adequately carry.