Construction Materials & Methods Flashcards
7 cards from real CMA 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 cause of 'concrete carbonation' and its main consequence for reinforced concrete?
Answer: Carbon dioxide reacts with calcium hydroxide, lowering pH and destroying rebar passivation
Atmospheric CO2 reacts with calcium hydroxide in concrete to form calcium carbonate, reducing the pH and destroying the passive oxide layer that protects embedded steel from corrosion.
Which masonry bond pattern staggers vertical joints but uses only stretchers (no headers), relying on metal ties for wythe connection?
Answer: Running (stretcher) bond
Running bond uses all stretchers with staggered vertical joints; in cavity and veneer walls, metal ties rather than masonry headers connect the wythes.
What does 'shotcrete' (sprayed concrete) offer as an advantage over conventionally placed concrete?
Answer: Ability to place concrete on vertical or overhead surfaces without formwork
Shotcrete is pneumatically projected at high velocity, consolidating against the receiving surface without formwork, making it ideal for tunnels, slopes, and irregular shapes.
In wood-frame construction, what is the purpose of 'blocking' installed between floor joists at mid-span?
Answer: To provide lateral stability and prevent joist rotation under load
Mid-span blocking (bridging) prevents wood joists from rotating or buckling laterally under load, distributing concentrated loads to adjacent joists.
Which membrane waterproofing material is applied as a liquid and cures to form a seamless elastomeric coating?
Answer: Fluid-applied polyurethane or silyl-terminated polyether (STPE) membrane
Fluid-applied membranes such as polyurethane or STPE are roller- or spray-applied as liquids, curing in place to create a seamless, monolithic waterproofing layer.
What is 'post-tensioning' in concrete construction, and when is it preferred over conventional reinforcing?
Answer: High-strength steel tendons stressed after concrete cures; preferred for long spans and thin slabs
Post-tensioning stresses high-strength tendons after the concrete reaches adequate strength, introducing compressive forces that offset tension, enabling longer spans and thinner sections.
Which flooring system uses a raised grid of pedestals to create an accessible plenum for mechanical and electrical distribution?
Answer: Raised access flooring (RAF) system
Raised access flooring consists of removable panels supported on adjustable pedestals, creating a plenum beneath the floor for flexible routing of cabling and HVAC.