Construction Materials & Systems Flashcards

Which ASTM standard governs the testing of compressive strength for hydraulic cement mortars?

Answer: ASTM C109

ASTM C109 covers the standard test method for compressive strength of hydraulic cement mortars using 2-inch cube specimens.

In curtain wall systems, what is the primary function of a pressure plate?

Answer: To clamp the glazing or infill panel to the framing member

Pressure plates mechanically clamp glazing or infill panels against a structural gasket on the curtain wall framing, securing them in place.

What distinguishes Type S mortar from Type N mortar per ASTM C270?

Answer: Type S has higher compressive strength and is used where high lateral loads occur

Type S mortar has a minimum compressive strength of 1,800 psi and is used where high lateral loads from wind or seismic forces must be resisted.

Which roofing membrane system relies on the weight of ballast rather than mechanical fasteners or adhesive to remain in place?

Answer: Loose-laid ballasted EPDM

Loose-laid ballasted EPDM systems are held down by gravel or pavers placed on top of the membrane rather than by fasteners or adhesive.

In a suspended acoustical ceiling system, what component directly supports the main runner?

Answer: Hanger wire

Hanger wires attach to the structure above and support the main runners (carrying tees) of a suspended acoustical ceiling grid.

What is the key advantage of using glass fiber reinforced concrete (GFRC) for architectural cladding panels?

Answer: It achieves high strength at significantly reduced panel weight

GFRC panels achieve compressive strengths comparable to conventional concrete but at roughly one-quarter the weight, enabling thinner, lighter cladding panels.

Which term describes the measure of a material's resistance to water vapor transmission?

Answer: Permeance

Permeance, expressed in perms, measures how readily water vapor passes through a material; lower permeance indicates a better vapor retarder.