Pile_Foundation Flashcards
A branch line feeds a fire hose 45’ from the riser, what’s its size?
1.25”
According to the code, steam pipe which must be buried by tunneling, the trench may be no longer than _________ when the trench is 14’ deep.
7
According to code, plates or sills shall be anchored to concrete foundation walls with bolts spaced not more than how far apart?
72”
According to code, what is the minimum thickness permitted for a concrete slab that is supported directly on the ground?
3 1/2”
A slab has just been placed and finished. It is normal concrete. According to code, unless accelerated curing methods are used, the slab must be cured in a moist condition for at least:
7 days
After one season, a concrete slab shows crazing and dusting and spalling. These defects were caused by:
Working the surface while bleed water was present
What should be done when the excavation for a footing is dug too deep in some places?
The excavation should be dug out so that the bottom is level and a thicker footing poured
Steel embedded in concrete almost always becomes:
Cathode
Horizontal members on the outside of prefabricated forms used to straighten and align forms are called
Walers
Piles are specified for a bridge. What action drives a single acting pile driver?
They fall by gravity
A contractor cannot place backfill material against a concrete structure wall until the concrete has developed a compressive strength of _____ PSI
3000
What is a Jackshore?
A single all metal adjustable post
Concrete consistency is determined by
Slump
Segregation in concrete walls is caused by:
Excessive water to cement ratio
According to design and control of concrete mixtures, water tightness in concrete is best achieved by which of the following
Low cement to water ratio
What is the main purpose for installing a sub-surface dewatering system
Lower water table
In what soil will a well-point dewatering system be most effective?
Sand
When is sheet piling installed in areas with a high water table
Before excavation
Concrete used in public works flood control and drainage systems must be air-entrained within what percentage range?
4%-7%
If the subgrade is damp prior to placing a concrete slab during hot dry weather, it will
Prevent the subgrade from drawing too much water from the concrete
Difference between piers and pilasters used in masonry construction?
Piers are isolated and freestanding whereas pilasters are built into a wall thickening a small wall section
When joints to control cracking in concrete slabs are cut, they should be cut to a depth of:
1/4 the slab thickness
What are all the tests that may be required in the project specs for concrete quality control?
Strength, slump, air
When super plasticizers are used in a concrete mix:
Less water will be needed for the same workability
Which factor does not affect the lateral pressure of plastic concrete form wall?
Use of air-entrained mixture
A failed concrete slab contains a construction joint. What is used to continue a construction joint through a concrete patch repair?
Permanent bond breaker
Concrete curing procedures for a new slab should begin immediately after:
Finishing is complete
After one season, a concrete slab shows crazing and dusting and spalling. These defects were caused during finishing by:
Overworking the concrete surface
A concrete slab is to be poured during hot dry weather. What is the result when the subgrade is moistened with water just before pouring the slab?
There will be an increase in the water to cement ratio, which reduces concrete strength
If concrete weighs 150 pounds per cubic foot, it will place a load on the forms of _______ pounds per square foot for each inch of slab thickness
10
To what depth are concrete control joints raked?
1/2”
Material that must be removed from reinforcing steel before placement
Dry mortar
Concrete blocks piers are being used to support a manufactured home. The cells must be reenforced with concrete and steel if the height of the piers exceeds a minimum of
48”
What are the minimum acceptable dimensions for a wood cap on a pier that is 42” high?
2x8x16
What is the minimum acceptable thickness for a masonry pier cap?
4”
Piers shall be spaced a maximum of how many feet on center?
8’
What is the minimum length of time that a concrete slab, beam, or footing (other than high early), must cure to achieve 70% of its design strength?
7 days
Purpose of bull floating a freshly placed slab is to
Embed large aggregates and level the surface
Troweling of a fresh concrete is performed following the _______ of the slab
Floating
Air entrainment of concrete is to
Improve the freeze thaw resistance
How many layers of concrete are in a slump test?
3
What type of pile has the most friction
Wood
What is a pile driven on an angle called?
Battered
A _________ is used to perform a slump test
Cone
Reinforcing steel in a slab is used for ________ strength
Tensile (flexural)