Chapter 21

Question 1

Lime is made by doing what?

Answer 1

Heating crushed limestone and then pulverizing it

Question 2

Quicklime reacts readily with water. True or false?

Answer 2

True

Question 3

Hydrated lime is obtained by treating what?

Answer 3

Quicklime with water

Question 4

Quicklime is most commonly used in building construction. true or false?

Answer 4

False

Question 5

Hydrated lime-water paste sets and hardens due to the ?

Answer 5

Chemical reaction of carbon dioxide in air with lime

Question 6

Which of the following materials is a pozzolana?

a. Portland Cement
b. Lime
c. Fly ash
d. Sand

Answer 6

C. Fly ash

Question 7

One of the important cementitious ingredients in making Roman concrete was?

Answer 7

Volcanic Ash

Question 8

Hydrated lime is available in two types, which are referred to as:

a. Types N and S lime
b. Types I and II lime
c. Types X and Y lime

Answer 8

A. Types N and S lime

Question 9

A pazzolanic material must be composed mainly of:

a. micrscopic silica
b. microscopic and amorphous silica
c. microscopic and crystalline

Answer 9

b. microscopic and amorphous silica

Question 10

The main ingredient used in the manufacture of Portland cement is?

Answer 10

Limestone

Question 11

ASTM specifications classify Portland cement into five basic types, referred to as:

a. Types A, B , C , D, E
b. Types I, II, III, IV, and V
c. Types PC1, PC2, PC3, PC4, and PC5

Answer 11

b. Types I, II, III, IV, and V

Question 12

The most commonly specified type of Portland Cement is:

Answer 12

Type I/II

Question 13

Which type of Portland cement is commonly used in making precast concrete members?

Answer 13

Type III

Question 14

White Portland cement is generally weaker than normal Portland cement. True or False

Answer 14

False

Question 15

The aggregate for concrete is generally subdivided into coarse aggregate and fine aggregate. The distinction between the two types of aggregate is based on the:

Answer 15

Aggregate’s particle size

Question 16

In a No. 4 sieve, the dimensions of voids are approximately:

a. 4 in. X 4in
b. 1/4 in. X 1/4 in.
c. 1 in. X 4 in.

Answer 16

b. 1/4 in. X 1/4 in.

Question 17

A well-graded coarse aggregate is one in which the size of all aggregate particles is approximately the same. True or False

Answer 17

False

Question 18

Everything else being the same, a concrete with a larger coarse aggregate requires less Portland cement and water paste to give the same concrete strength. True or False

Answer 18

True

Question 19

Lightweight structural concrete is heavier than insulating concrete. True or False

Answer 19

True

Question 20

The slump of concrete is measured:

a. when the concrete is fresh
b. 28 days after casting the concrete test specimen
c. 14 days after casting the concrete specimen

Answer 20

when concrete is fresh

Question 21

The slump of concrete is measured by:

a. compressive strength of concrete
b. tensile strength of concrete
c. workability of concrete

Answer 21

c. Workability of concrete

Question 22

The test specimen used for determining the compressive strength of concrete in the United States is a :

a. 6in. diameter, 6in. high cylinder
b. 6in. diameter , 12 in. high cylinder
c. 6in. diameter, 18in. high cylinder

Answer 22

b. 6in. diameter, 12 in, high cyinder

Question 23

The compressive strength of concrete is generally measured:

a. when the concrete is fresh
b. 28 days after casting the concrete in a test specimen
c. 14 days after casting the concrete in a test specimen

Answer 23

b. 28 days after casing the concrete in a test specimen

Question 24

In a high-rise building, the concrete may be brought from the ground to the location of placement by:

a. chutes
b. buckets
c. pumping
d. a or b
e. b or c

Answer 24

b or c

Question 25

After concrete has been placed in the form, it should be consolidated as much as is economically practical. True or false?

Answer 25

False

Question 26

The consolidation of concrete on a construction site are generally done: a. Manually using a 2in diameter, 3 ft long steel rod b. manually using a 1in diameter, 3 ft long steel rod c. using a power-driven rod vibrator d using a power-driven plate vibrator

Answer 26

c. using a power-driven rod vibrator

Question 27

The finishing operations of concrete surface usually involve striking, floating, and troweling. The sequence in which these three operations are generally performed is?

Answer 27

Striking, Floating, and troweling

Question 28

Portland cement sets and gains strength by virtue of its chemical reaction with?

Answer 28

Water

Question 29

The rate at with concrete gains strength increases as the ambient air pressure increases. True or false?

Answer 29

True

Question 30

High strength concrete is defined as concrete whose compressive strength is greater than or equal to how much psi?

Answer 30

6,000psi

Question 31

A high strength concrete generally requires a: a. water-increasing agent b. water reducing agent c. sand reducing agent d. sand increasing agent

Answer 31

b. water reducing agent

Question 32

Steel reinforcing bars, generally used in concrete, have a yield strength of how much ksi?

Answer 32

60ksi

Question 33

A #8 reinforcing bar has a diameter of: a. 1/8in. b. 8in. c. 1in. d. none of the above

Answer 33

c. 1in.

Question 34

In a welded wire fabric mat that has a designation of | 8 X 8-D4.0 X 4.0, the number 4.0 indicates that the wires are?

Answer 34

Deformed wires, each with a cross-sectional area of 0.04in squared.

Question 35

Epoxy-coated bars are generally used in: a. high-rise buildings built in warm climates b. parking garages built in warm climates c. high-rise buildings d. parking garages built in cold climates

Answer 35

d. parking garages in cold climates