Vol 2 Flashcards
If you are laying out an area for concrete, how many inches on each side should you allow for the width of the forms?
6 inches
On a centerline stake, where is the amount of earthwork to be done marked?
Back
What type of cut is made to lower the grade for the road or runway?
Through
The base course distributes wheel loads to the?
Subgrade
What two construction materials can you recycle to use for other purposes?
Asphalt and Concrete
What percentage of slightly plastic silt and clay is present in a satisfactory base course mix when added to crushed rock?
10%
What is the numerical value of π?
3.14
How many cubic feet are in 1 cubic yard?
27ft
What information must you ask the company providing base course in order to get an exact amount of base course for your project?
The exact weight of their material.
To compensate for low spots in the subgrade when you are computing base course materials, what percentage of the computed volume should you add to your order?
5%
What is directly or indirectly responsible for most pavement failures and deterioration?
Water
Storm drains should not be used except where the slope of the ground is not suited for ditches, gutters, or flumes, and where
Space is restricted
Which of these conditions is not a function of subsurface drainage?
a. To intercept seepage or underground springs.
b. To divert water away from structures.
c. To lower the water table.
d. To raise the water table.
To raise the water table.
If you are installing culverts or storm drains, the bottom of the trench should be
Shaped to fit the pipe.
What can you do if you want to funnel water into the inlet of a culvert?
Flare the End Walls
French drains are not recommended for permanent construction because they have
A tendency to silt up
You should treat the bottom of vertical dry wells with calcium chloride or hay to
Prevent Freezing
Holes in perforated pipe should be placed UP when the
structure is to be placed along the side of the pavement
After you place either your impervious soil layer or filter material for a subsurface structure, make sure the bottom of the trench is
Shaped to fit the pipe.
The purpose of a drainage inspection is to report on the
Condition
Function
and safety of the items inspected
What type of drainage inspection should you do during or immediately after a rainstorm?
Operational
When should you do a maintenance check?
After all water has cleared the structure.
What are the types of drainage defects?
Breaks
Erosion
Vegetation and Obstructions.
You should install a drop inlet at the end of a culvert to
Control Silting
What type of Portland cement is used in large masses of concrete, such as large dams?
IV
What percent of the volume of a concrete mix is aggregates?
60-75.
How many gallons per yd3 of water can be added at the jobsite without detrimental effects?
1-2
One purpose of air-entraining agents is to
Increase resistance to the action of chemicals
What is generally considered to be the third dimension in a measurement?
Depth
If the shape of your concrete project is not common, what can you do to simplify calculating the concrete you need?
Break the shape up into common shapes and add them together
What type of string should you use as a guide for setting forms?
Nylon
What holds the steel form firmly against the stake?
Wedges
If a dowel is to be placed across an expansion joint, it must be
Smooth
You can prevent wooden keyways from cracking by
Oiling and Grooving with a saw kerf
What is the purpose of using tie bars in concrete?
Hold slabs together
When installing multiple sections of welded wire fabric, how much should be overlapped?
6 inches
Footings and other principal structural members should have at least how many inches of concrete between the steel reinforcement and the ground?
3 inches
What can you do to the pile of concrete after a slump test is completed to indicate its cohesiveness, workability, and place ability?
Tap gently with tamping rod
Why must the ends of cylinders used for testing be finished carefully?
If not perfectly flat, the results could be skewed.
What is the most common mix for concrete when mixing it by hand?
1 part cement + 2 parts sand + 3 parts gravel
How long should the first cubic yard of concrete be mixed in a portable concrete mixer for a medium job?
1-Minute
When a transit truck is used, the concrete should be delivered and discharged within
1½ hours.
When transporting concrete, you should be careful to prevent
Segregation
What is it called when large voids are visible in concrete that hasn’t been consolidated properly?
Honeycomb
What is the most widely used mechanical method for consolidating concrete?
Vibration
What type of joint is installed to relieve compressive stresses of a slab?
Expansion
Which curing method is most effective for the prevention of mix water evaporation?
Water curing
Which curing method should you not use when discoloration is objectionable?
Plastic Films
When should you apply chemical membranes?
As soon as the concrete is finished
What is the MOST IMPORTANT part of landscaping
Drainage
You cannot conduct a walking inspection when
Time is a critical factor
In what United Facilities Criteria (UFC) can the guidance concerning pavement maintenance management be found?
UFC 3-270-05
What is the most common cause of cracking in concrete pavements?
Overloading by traffic
The defect characterized by chipping or breaking away of concrete at joints, cracks, or edges is called
Spalling
When you saw concrete for a partial-depth repair, you should adjust the blade to cut a minimum depth of
2-Inches
For a partial depth concrete repair, you want to remove
The defective concrete only
When should you apply bonding agents?
Immediately before the repair material is placed
When performing a full-depth repair, how much material must be removed?
Until hard, firm soil is reached
You should add calcium chloride to a concrete mixture to
Increase the concretes early strength
What is the diameter of a random crack-saw blade?
5 Inches
During crack cleaning, what serves the same purpose as brooming, but is much more efficient
High Pressure Air
How much wider than the joint must the backer rod be when it is compressed into the joint
25%
Today’s asphalt cements are graded according to
Performance Grade
What type of asphalt emulsion has little or no ability to mix with an aggregate?
Rapid Setting (RS)
Which type of asphalt emulsion is developed for slurry seals?
Quick-set (QS)
Which of these materials can be used with damp aggregate?
Asphalt Emulsion
Bituminous surfaces must be constructed on bases that are reasonably dry and free from
caked mud or dust
Bituminous construction normally should be suspended when the temperature goes below
50F
What is the purpose of a Tack Coat?
Acts as glue between two layers of asphalt
What is the purpose of a Prime Coat?
Waterproofs the surface
Because of environmental concerns, the best materials to be used as prime coats are
Emulsions
What is the most widely used type of flexible pavement construction material?
Central plant mix
Can you use the same weight of asphalt for multiple mixes when computing requirements?
No, asphalt weight varies by mix design.
What shape should a load of hot mix asphalt have in the bed of a dump truck?
Dome
When inspecting a truck of asphalt, blue smoke indicates the mix is
Burnt
One advantage of a bituminous paver over a motor grader is that the bituminous paver
Saves spreading time
Breakdown rolling is best done with
steel-wheeled rollers.
Where should the breakdown rolling operation start after joints have been pinched?
The Low Side
How far from the lower unsupported edge should the rolling process start for thick lift construction?
12-15Inches
Under which condition would you operate the steel-wheeled roller with the tiller wheel forward?
The grade is excessive
Finish rolling is done solely to
Improve the Surface
What types of cracks are interconnected and form a series of small blocks resembling chicken wire?
Alligator
What type of crack in flexible pavement is caused by a lack of bond between the surface layer and the course beneath?
Slippage
Where do corrugations in flexible pavement normally occur?
At points where traffic brakes and accelerates.
The progressive loss of surface material from flexible pavement by traffic abrasion is called
Raveling
When should asphalt pavements be inspected
Spring and Fall
Large cracks in pavement is repaired the same way as
Potholes
Small and medium cracks in flexible pavement can be sealed individually with a
Prepared Joint Sealer
What item is used to force sealing material into the cracks in flexible pavements?
Squeegee
Which item should you use to mark defective flexible pavement?
Crayon
As you mark an area for removal of defective flexible pavement, how far into the good pavement should you make your marks?
12 Inches
When removing defective flexible pavement, you should remove base course materials until
you reach firm, dry material
When should the rolling operation for pavement repair using hot-mix begin?
Immediately after the material is placed.
Which of the following is not a purpose of a bituminous surface treatment?
Strengthen the Surface
What should be used to seal hairline cracks in asphalt pavements?
Fog Sea,
Each additional layer of aggregate for a multiple surface treatment should be about
one half the size of the previous layer
One purpose of an emulsion slurry seal is to
prevent moisture intrusion into the pavement
Immediately before you apply slurry, the pavement surface should be thoroughly cleaned, broomed, and
Moistened with a light application of water
Road shoulders protect the basic pavement structure by giving what kind of support/
Lateral
What do shoulders provide motorists?
An emergency lane
What type of road shoulder exists along narrow pavements, inside curves and at intersections?
Dual-Type
