QUIZ 4 CONCRETE AGGREGATES

Aggregates may affect the following properties of concrete except :

• STRENGTH

• ELASTICITY

• DURABILITY

• ECONOMY

Which property of aggregate affects the workability of fresh mass and the bond between the aggregate and cement paste in hardened concrete?

• Mineral character

• Amount of aggregate in unit volume of concrete

• Surface characteristics

• Grading of aggregate

What is the classification of aggregates based on petrological characteristics?

• Igneous rocks, sedimentary rocks, metamorphic rocks

• Fine aggregate, coarse aggregate

• Heavy weight, normal weight, light weight

• Natural aggregate, manufactured aggregate, recycled-concrete aggregate

What is the unit weight range for normal-weight concrete aggregates according to ASTM C33?

• Up to 6400 kg/m3

• 250 to 1450 kg/m3

• 2200 to 2400 kg/m3

• 1350 to 1850 kg/m3

Which type of aggregate is obtained from natural deposits without change in their nature during production?

• Manufactured aggregate

• Marine-dredged aggregate

• Recycled-concrete aggregate

• Natural aggregate

What is the grain size diameter (in mm) that serves as a boundary limit for the coarse aggregate and fine aggregate?

• 5

• 3

• 8

• 10

How can the amount of aggregate sample be reduced using the 'Quartering' method?

• Discard the entire sample

• Divide into eight equal parts

• Divide into four equal quarters

• Divide into two equal halves

What type of particle shape has sharp corners and shows little evidence of wear?

• Flaky

• Irregular

• Rounded

• Angular

Which characteristic of aggregates refers to the bond between cement paste and aggregate?

• Absorption and surface moisture

• Specific Gravity

• Resistance to abrasion

• Unit weight

What is the significance of sampling aggregates in the testing process?

• It is not important

• It is more important than testing

• It is equally important as testing

• It is less important than testing