Concrete, Aggregates, Admixtures

Question 1

of cement is usually measured indirectly by measuring
the surface area with Blaine air permeability.

Answer 1

Soundness

Question 2

Wagner turbidimeter is used to determines the surface area by
measuring the rate of sedimentation of cement suspended in

Answer 2

kerosene

Question 3

Fineness can also be measured by determining the percent
passing the sieve diameter of

Answer 3

0.045 mm

Question 4

Refers to the stiffening of the cement paste or the change from a
plastic state to a solid state

Answer 4

Setting

Question 5

set time must allow for handling and placing the
concrete before stiffening.

Answer 5

initial setting

Question 6

Refers to its ability to retain its volume after setting of the cement
paste

Answer 6

Soundness

Question 7

The autoclave expansion test is used to check the ____ of the
cement paste.

Answer 7

Soundness

Question 8

The acceptance criteria for questionable water are specified in
ASTM __

Answer 8

C94

Question 9

After 7 days, the average compressive strength of mortar cubes
made with the questionable water should not be less than _____
of the average strength of cubes made with potable water.

Answer 9

90%

Question 10

Aggregate particles that are retained on a 4.75 mm sieve (No. 4)

Answer 10

Coarse

Question 11

Aggregate particles that pass a 4.75 mm sieve (No. 4).

Answer 11

Fine

Question 12

One sieve size larger than the nominal maximum aggregate size

Answer 12

Maximum size

Question 13

One sieve larger than the first sieve to retain more than 10% of the
aggregates.

Answer 13

Nominal Maximum

Question 14

Two considerations in the shape of the material: angularity
and_____.

Answer 14

flakiness

Question 15

Referred to as flat and elongated, describes the relationship
between the dimensions of the aggregate.

Answer 15

Flakiness

Question 16

It is desirable to use rounded and smooth aggregates to improve
the ____ of fresh concrete during mixing.

Answer 16

workability

Question 17

Angular and rough particles are desirable for asphalt concrete and
base courses to increase the ____of the materials in the field.

Answer 17

Stability

Question 18

The Superpave mix design method recognizes an angularity test,
Test Method for Uncompacted Void Content. A test for ___.

Answer 18

Fine

Question 19

The ability of aggregate to withstand weathering is defined as ___.

Answer 19

Toughness

Question 20

The ability of aggregates to resist the damaging effect of loads is
related to the ____of the aggregate particles and is described as
abrasion resistance.

Answer 20

hardness

Question 21

The aggregate may have some moisture but the saturation state is
not quantified.

Answer 21

air dry condition

Question 22

The aggregate contains no moisture; this requires drying the
aggregate in an oven to a constant mass.

Answer 22

Bone dry

Question 23

Defined as the moisture content in the SSD condition

Answer 23

Absorption

Question 24

The aggregate’s voids are filled with moisture but the main surface
area of the aggregate particles is dry

Answer 24

(SSD) condition

Question 25

The moisture content in the aggregate in excess of the moisture content in the SSD condition.

Answer 25

Free moisture

Question 26

Field samples must be reduced using the following except:

Answer 26

slump

Question 27

There are four major reasons for using admixtures except:

Answer 27

to substitute the quality of aggregates in the concrete mix

Question 28

This admixture is recommended for all concrete exposed to freezing.

Answer 28

Air entraining

Question 29

When superplasticizers are used, the fresh concrete stays workable for a short time, _____ minutes, and is followed by rapid loss in workability.

Answer 29

30-60mins

Question 30

Advantages of retarding admixtures except

Answer 30

increase the time between the initial and final set

Question 31

an ultrafine gray powder, binds sand and rocks into a matrix of concrete.

Answer 31

Cement

Question 32

A cement which possesses the property of hardening in combination with water

Answer 32

HYDRAULIC CEMENT

Question 33

It is the product obtained by pulverizing clinker consisting of hydraulic calcium silicates

Answer 33

Portland Cement

Question 34

Hydrates and hardens rapidly and is largely responsible for initial set and early strength.

Answer 34

Tricalcium silicate

Question 35

Hydrates and hardens slowly and is largely responsible for strength increases beyond one week.

Answer 35

Dicalcium silicate

Question 36

Hydrates and hardens the quickest.

Answer 36

Tricalcium aluminate

Question 37

___ undergo a series of chemical reactions that cause it to harden or set.

Answer 37

Hydration

Question 38

a siliceous and aluminous material in finely divided form react with calcium hydroxide at ordinary temperatures to form compounds having cementitious properties.

Answer 38

Pozzolan Cement

Question 39

Apperance of water on the surface of the concrete after it has consolidated but before it is set.

Answer 39

Bleeding