Concrete

Question 1

Is the process of measuring concrete mix ingredients by either mass or volume and introducing them into the mixture.

Answer 1

Batching

Question 2

Most specs require batching be done by

Answer 2

Mass rather than by volume

Question 3

Concrete is sometimes mixed at the job site in a

Answer 3

Stationary mixer or paving mixer

Question 4

Many specs require a minimum mixing time of

Answer 4

1 minute plus 15 seconds for every cubic meter (yard)

Question 5

Wood forms, unless oiled or otherwise treated with a form-release agent, should be moistened before placing concrete, otherwise they will

Answer 5

absorb water from the concrete and swell.

Question 6

However, if a _________ is not used to control the flow of concrete onto sloped surfaces at the end of an inclined chute, segregation can occur.

Answer 6

Baffle

Question 7

The diameter of the tremie pipe should be at least ____ times the diameter of the maximum size of aggregate.

Answer 7

8

Question 8

__________________________ makes easy work of placing concrete underwater.

Answer 8

Mobile concrete pumps with a variable radius boom

Question 9

_________________ is the process of compacting fresh concrete; to mold it within the forms and around embedded items and reinforcement; and to eliminate stone pockets, honey- comb, and entrapped air

Answer 9

Consolidation

Question 10

___________ is the process of cutting off excess concrete to bring the top surface of a slab to proper grade.

Answer 10

Screeding or strikeoff

Question 11

To eliminate high and low spots and to embed large aggregate particles, a _________________ should be used immediately after strikeoff.

Answer 11

Bull Float or Darby

Question 12

___________ must be completed before bleed water accumulates on the surface.

Answer 12

Bull floating or darbying