CSLB Concrete C8 License Practice Test 1,2,3 and 4
DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY
GRADED A+
What is the volume of a cylinder if the diameter equals 3 feet
and the length equals to 12 feet? - CORRECT ANSWER
84.78 cubic feet
Explanation:
There are two ways to solve the problem. However,
regardless of which method is used, you need to first
determine the area of the circle then multiply it by the
length.Traditional MethodUse the following formula:Area of
the circle = π x r x rWhere π = 3.14 and radius (r) = 1.5 feet
(half of the diameter length)Area = 3.14 x 1.5 x 1.5Area =
7.065 sq. ft.Multiply area by the length to find the
volume.7.065 x 12 = 84.78Shortcut MethodArea of the circle
is 78.5% of the square. Treat the circle as a square and
solve for the area.Find the area of the square instead of the
circle.3' x 3' = 9 sq. ft.Since circle is 78.5% of the square,
multiply area of the square by 78.5% (or .785 if there is no
percentage sign on the calculator).9 sq. ft. x .785 = 7.065
square feetMultiply area by the length to find the
volume.7.065 x 12 = 84.78 cubic feet
Where are spiral rebar ties used? - CORRECT ANSWER
In round columns
,Control joints in sidewalks should be spaced at what
intervals? - CORRECT ANSWER Equal to the width of
the slab
Explanation:
Generally the control joints in sidewalks should be spaced
equal to the width of the slab, but not more than 6 feet
apart.
One cubic foot of cement weighs approximately: -
CORRECT ANSWER 95 lbs
How many cubic yard of concrete is required for a 4" slab
with the diameter of 15 feet? - CORRECT ANSWER 2
½ cubic yards
Explanation:
Traditional MethodUse the following formula:Area of the
circle = π x r x rWhere π = 3.14 and radius (r) = 7.5 feet (half
of the diameter length)Area = 3.14 x 7.5 x 7.5Area = 176.625
sq. ft.Multiply area by the depth of the slab (in feet) to find
the volume in cubic feet.176.625 x .333 = 58.82 cubic
feetConvert cubic feet into cubic yards.58.82 ÷ 27 = 2.18
cubic yardsSince 2.18 is not a given option, round up the
number to 2.5 cubic yardsShortcut MethodThis problem can
be solved using a much simpler method. First is to find the
area of the square, then convert it into the area of the circle
by multiplying it by 78.5%.Area of the square = 15' x 15' =
225 square feetArea of the circle = 225 x .785 = 176.625
square feetDivide the volume by 81 to solve for the cubic
yards for a 4" slab.176.625 ÷ 81 = 2.18 cubic yardsSince 2.18
is not a given option, round up the number to 2.5 cubic yards
,The normal tolerance for the location of bends and ends of
reinforcing bar is: - CORRECT ANSWER +/- 2 inches
How many cubic yards of backfill are required for a 3' x 5'
trench, 1500 ft long, with a 1 foot diameter pipe? -
CORRECT ANSWER 789.72
Explanation:
Step 1. Find the net face area of the trench deducting for
pipe.Face area including pipe: 3 x 5 = 15 square feetArea of
the pipe: 𝐴=𝜋𝑟2A = 3.14 x .5 x .5A = 0.785Find the face area
of the trench minus area of the pipe, which will give you the
net area for the backfill.15 - 0.785 = 14.215Step 2. Find the
total volume of the backfill.14.215 x 1500 = 21322.5 cubic
feetConvert the volume into cubic yards.21322.5 ÷ 27 =
789.72 cubic yards
When can the live load be calculated by multiplying the
height, width and length of a pour and dividing by the
deadload? - CORRECT ANSWER Never
Tensile strength in concrete is achieved by: - CORRECT
ANSWER The use of steel reinforcement.
Refer to the house plan. What is the total cost for the
foundation slab if the contractor charges $3.54 per square
foot? - CORRECT ANSWER $6524.90
Explanation:
, The easiest way to solve for the area of the slab is to image
a full rectangle of the slab and subtract void areas from the
area of the slab.
Rectangle area: 28.167' x 71.5'= 2013.94 sq ftLeft void area:
6.667' x 1.83' = 12.2 sq ftCenter void area: 11.5' x 1.83' =
21.045 sq ftRight void area: 9.167' x 15' = 137.505Net area of
the foundation slab: 2013.94 - 12.2 - 21.045 - 137.505 =
1843.19 sq ft.Calculate the price of the slab.1843.19 sq ft x
$3.54 = $6524.90
What is the minimum spacing of parallel reinforcing bars
placed in two or more layers? - CORRECT ANSWER 1
inch
Explanation:
According to the American Concrete Institute, where
parallel reinforcement is placed in two or more layers, bars
in the upper layers shall be placed directly above bars in the
bottom layer with clear distance between layers not less
than 1 inch.
When applying concrete to concrete there are several
factors to consider. Which is most important? - CORRECT
ANSWER In most cases the most important is the bond.
What is the purpose of the rebar? - CORRECT ANSWER
To increase the tensile strength
There are many ornamental uses of concrete, including
casting architectural elements, ornaments, and faux
finishes. How would you describe terrazzo in the simplest
DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY
GRADED A+
What is the volume of a cylinder if the diameter equals 3 feet
and the length equals to 12 feet? - CORRECT ANSWER
84.78 cubic feet
Explanation:
There are two ways to solve the problem. However,
regardless of which method is used, you need to first
determine the area of the circle then multiply it by the
length.Traditional MethodUse the following formula:Area of
the circle = π x r x rWhere π = 3.14 and radius (r) = 1.5 feet
(half of the diameter length)Area = 3.14 x 1.5 x 1.5Area =
7.065 sq. ft.Multiply area by the length to find the
volume.7.065 x 12 = 84.78Shortcut MethodArea of the circle
is 78.5% of the square. Treat the circle as a square and
solve for the area.Find the area of the square instead of the
circle.3' x 3' = 9 sq. ft.Since circle is 78.5% of the square,
multiply area of the square by 78.5% (or .785 if there is no
percentage sign on the calculator).9 sq. ft. x .785 = 7.065
square feetMultiply area by the length to find the
volume.7.065 x 12 = 84.78 cubic feet
Where are spiral rebar ties used? - CORRECT ANSWER
In round columns
,Control joints in sidewalks should be spaced at what
intervals? - CORRECT ANSWER Equal to the width of
the slab
Explanation:
Generally the control joints in sidewalks should be spaced
equal to the width of the slab, but not more than 6 feet
apart.
One cubic foot of cement weighs approximately: -
CORRECT ANSWER 95 lbs
How many cubic yard of concrete is required for a 4" slab
with the diameter of 15 feet? - CORRECT ANSWER 2
½ cubic yards
Explanation:
Traditional MethodUse the following formula:Area of the
circle = π x r x rWhere π = 3.14 and radius (r) = 7.5 feet (half
of the diameter length)Area = 3.14 x 7.5 x 7.5Area = 176.625
sq. ft.Multiply area by the depth of the slab (in feet) to find
the volume in cubic feet.176.625 x .333 = 58.82 cubic
feetConvert cubic feet into cubic yards.58.82 ÷ 27 = 2.18
cubic yardsSince 2.18 is not a given option, round up the
number to 2.5 cubic yardsShortcut MethodThis problem can
be solved using a much simpler method. First is to find the
area of the square, then convert it into the area of the circle
by multiplying it by 78.5%.Area of the square = 15' x 15' =
225 square feetArea of the circle = 225 x .785 = 176.625
square feetDivide the volume by 81 to solve for the cubic
yards for a 4" slab.176.625 ÷ 81 = 2.18 cubic yardsSince 2.18
is not a given option, round up the number to 2.5 cubic yards
,The normal tolerance for the location of bends and ends of
reinforcing bar is: - CORRECT ANSWER +/- 2 inches
How many cubic yards of backfill are required for a 3' x 5'
trench, 1500 ft long, with a 1 foot diameter pipe? -
CORRECT ANSWER 789.72
Explanation:
Step 1. Find the net face area of the trench deducting for
pipe.Face area including pipe: 3 x 5 = 15 square feetArea of
the pipe: 𝐴=𝜋𝑟2A = 3.14 x .5 x .5A = 0.785Find the face area
of the trench minus area of the pipe, which will give you the
net area for the backfill.15 - 0.785 = 14.215Step 2. Find the
total volume of the backfill.14.215 x 1500 = 21322.5 cubic
feetConvert the volume into cubic yards.21322.5 ÷ 27 =
789.72 cubic yards
When can the live load be calculated by multiplying the
height, width and length of a pour and dividing by the
deadload? - CORRECT ANSWER Never
Tensile strength in concrete is achieved by: - CORRECT
ANSWER The use of steel reinforcement.
Refer to the house plan. What is the total cost for the
foundation slab if the contractor charges $3.54 per square
foot? - CORRECT ANSWER $6524.90
Explanation:
, The easiest way to solve for the area of the slab is to image
a full rectangle of the slab and subtract void areas from the
area of the slab.
Rectangle area: 28.167' x 71.5'= 2013.94 sq ftLeft void area:
6.667' x 1.83' = 12.2 sq ftCenter void area: 11.5' x 1.83' =
21.045 sq ftRight void area: 9.167' x 15' = 137.505Net area of
the foundation slab: 2013.94 - 12.2 - 21.045 - 137.505 =
1843.19 sq ft.Calculate the price of the slab.1843.19 sq ft x
$3.54 = $6524.90
What is the minimum spacing of parallel reinforcing bars
placed in two or more layers? - CORRECT ANSWER 1
inch
Explanation:
According to the American Concrete Institute, where
parallel reinforcement is placed in two or more layers, bars
in the upper layers shall be placed directly above bars in the
bottom layer with clear distance between layers not less
than 1 inch.
When applying concrete to concrete there are several
factors to consider. Which is most important? - CORRECT
ANSWER In most cases the most important is the bond.
What is the purpose of the rebar? - CORRECT ANSWER
To increase the tensile strength
There are many ornamental uses of concrete, including
casting architectural elements, ornaments, and faux
finishes. How would you describe terrazzo in the simplest
