CPC Construction Methods & Materials Flashcards
6 cards from real CPC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CPC Construction Methods & Materials flashcards as text
What does the water-cement (w/c) ratio primarily control in a concrete mix design?
Answer: Strength and durability
The w/c ratio is the single most important factor controlling concrete compressive strength and durability; lower ratios produce stronger, more durable concrete.
In post-tensioned concrete construction, when are the tendons typically stressed?
Answer: After concrete has reached sufficient strength
Post-tensioning tendons are stressed after the concrete has cured and reached the required strength, typically around 75% of design strength.
Which type of formwork system uses large prefabricated panels that can be reused many times on repetitive floor plates?
Answer: Flying form (table form) system
Flying forms (table forms) are large prefabricated assemblies that are flown by crane from floor to floor, reducing labor and increasing reuse cycles.
What is the primary function of a vapor retarder placed under a concrete slab-on-grade?
Answer: Prevent moisture migration from soil into the slab
A vapor retarder placed beneath slabs-on-grade prevents ground moisture from migrating upward through the concrete, protecting floor coverings and equipment.
In structural steel erection, what is the purpose of a 'safety cable' installed between columns?
Answer: Provide fall protection for ironworkers walking on beams
Safety cables (perimeter cables) are installed between columns to provide fall protection for ironworkers, as required by OSHA 1926 Subpart R.
Which soil improvement technique involves injecting a grout mixture into loose granular soil to densify and strengthen it?
Answer: Compaction grouting
Compaction grouting injects a stiff, low-slump grout under pressure to displace and densify surrounding loose granular soils.