The maximum size of the conduit or pipe shall NOT exceed _______ of the thickness of the concrete.
1/3
Which of the following tests for concrete
... [Show More] is conducted at the site/field?
Color Test
Explanation:
Rest of the above are laboratory tests.
If the concrete compressive strength specified is less than 3600 psi, it has the option of being tested at 28 days and is able to accept the concrete if it attains ___________ percentage of the minimum required strength.
85
If the admixtures are used in concrete for the purpose of delayed setting and hardening of concrete, they are called _____________?
Retarders
Which of the following are the general types of vibrating needles that are in use?
ALL ANSWERS!
-Internal vibrators
-Immersion vibrators
-Surface vibrators
Concrete proportioning is done based on the facilities available at the site. Which are the general proportioning methods used for concrete?
ALL OF THESE
-Surface area method
-Mix design based on flexural strength
-Maximum destiny method
The minimum cementitious material that is required for concrete bridging deck is ______________lbs/cu yd.
675
The amount of free water used in concrete shall not exceed ____________ pounds per cubic yard of concrete.
310
Explanation:
If the SCM are added, it can be increased to 20 pounds per each required 100 pounds of cementitious material in excess of 550 pounds per cubic yard.
If the concrete curbs are to be constructed over the existing pavement, _______________ are used to fix them to pavement.
Steel dowels
Which of the following is NOT an example of blended cement?
Combination of silica fume and chlorine fluoride
Explanation:
Blended cement is a combination of either Type || or Type V cement with any of the SCM
Which of the following is a line at which the face of the curb meets the top of the payment?
Control Joint
Which of the following is NOT used as concrete chemicals?
Abrasion bonding compound
Explanation:
Concrete curing compound and polymer bonding agent are both concrete chemicals.
The admixtures that are used in concrete to improve durability in freeze/thaw environments are ________________.
Air entrainment admixtures
The fly ash which is used as SCM has the specific gravity ___________________.
1.9 - 2.8
The leveling operation that removes lumps and hollows and provides a true and uniform concrete surface is called ______________________.
Screeding
If the quantity of concrete is less than _____________ cubic yards, the compliance test reports are not required.
50
Which type of Portland cement is used when early strength is expected?
Type |||
Which of the following factor influence the positioning of the joints in a slab on grade?
ALL OF THESE
-Sub grade conditions
-Finishing requirements
-Temperature
Which of the following is NOT a property of concrete?
High tensile strength
The concrete work is done in freezing zones, it gets cured by ______________.
Steam
Explanation:
It is done by heating concrete by steam or using alternating current, so that water content in the concrete is not increased.
Coarse aggregate in concrete is the material that is retained in sieve number ____________.
#4
Explanation:
The one which passes through sieve #4 is the fine aggregate.
All of the structural steel is considered satisfactory even if it is rusted, but still meets the density requirements, except ___________________.
Pre stressing steel
Explanation:
If the pre stressing steel is rusted, it cannot be used since it does not meet the compliance requirements.
The compressive strength of concrete when treated with a 4" cube is always ____________ than when tested with a 6" cube.
More
The practice of making concrete to achieve the stipulated minimum strength and durability and to make concrete in the best economical manner is called _________________.
Mix design
Explanation:
Mix design uses the theoretical calculations to get the desired higher strength in concrete but yet consuming minimum cement.
What is the purpose of using SCM in concrete other than meeting workability requirements?
To avoid emissions:
The cement production is responsible for 7% of the greenhouse gas emissions (GHG).
If the contractor has to transport the concrete, what is the specified time for the concrete after catching under normal circumstances?
Before 1 1/2 hours
Explanation:
Or before 250 revolutions of the drum
What is NOT a key purpose in using SCM in concrete?
Short term curing period
The rough concrete finishes are generally appropriate for surfaces subject to _______________.
Traction
Why would the cylindrical/circular columns be chosen over the square/rectangular columns?
Circular columns carry more load.
Explanation:
For the given cross section area, circular columns carry more load as compared to square/rectangular columns.
The size of the vibration needle to be used for concrete vibration for slab is ______________ inch.
3/4" (20mm)
Explanation:
It is based on the thickness of the slab, generally 3/4" needle is used and in rare cases 1 1/2" needle is also used.
What are the compliance requirements that the concrete must meet to pass the acceptance test?
ALL OF THESE!
-Homogeneity
-Strength
-Workability
The additives used to enhance the performance of concrete for the special purposes is/are called:
Chemicals
Explanation:
Shall not be confused with admixtures
Which of the following are the factors that affect the pulse velocity measurement on concrete?
ALL OF THESE!
Explanation:
-Temperature on concrete
-Presence of reinforcing steel
-Smoothness of the surface
Which of the following is NOT a concrete curing method?
Water entrapment curing [Show Less]