BC chapter 10

Question 1

concrete

Answer 1

strong, hard building material produced from a mixture of portland cement and a aggregate filler/binder to which water is added to form a slurry that sets into a rigid building material.

Question 2

concrete is strong

Answer 2

in compression but weaker in tension…ultimate compressive strength can range from 2500 to 6000 psi

Question 3

rebar sizes are commonly referred by standardized number

Answer 3

the most commonly used size is #5

Question 4

precast concrete

Answer 4

is placed in forms and is cured at a plant away from the job site

Question 5

common applications for concrete

Answer 5

• pavement
• foundations
• columns
• floors
• walls
• concrete masonry units (CMU)

Question 6

the single most important factor in determining the ultimate strength of concrete is

Answer 6

water-to-cement ratio

Question 7

slump test

Answer 7

method of evaluating the moisture content of wet concrete by measuring the amount that a small,cone-shaped sample of the concrete slumps after it is removed from a standard- sized test mold.

Question 8

spalling

Answer 8

primary cause of spalling is the expansion of the moisture with in the concrete when heated or frozen

Question 9

flat-slab concrete frames

Answer 9

consists of a concrete slab with concrete columns for support …the slab of concrete ranges in thickness from 6 to 12 inches

Question 10

advantages to using precast concrete

Answer 10

• higher degree of quality control possible than with cast-in- place concrete
• work can proceed more quickly at the job site
• precast concrete sandwich panels can be produced using a polystyrene core to improve the insulating properties of the precast concrete

Question 11

disadvantage to using precast concrete

Answer 11

is the need to transport the finish components to the job site

Question 12

standard shapes of precast concrete

Answer 12

slabs
hollow core slabs
single tee
double tee