CSLB CONCRETE C8 LICENSE PRACTICE TEST #1
What is the volume of a cylinder if the diameter equals 3 feet and the length equals to
12 feet? - 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? - Answer -In round columns
Control joints in sidewalks should be spaced at what intervals? - 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: - Answer -95 lbs
How many cubic yard of concrete is required for a 4" slab with the diameter of 15 feet? -
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: - 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? - 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? - Answer -Never
Tensile strength in concrete is achieved by: - 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? - 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? -
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? - Answer -In most cases the most important is the bond.
What is the purpose of the rebar? - Answer -To increase the tensile strength
What is the volume of a cylinder if the diameter equals 3 feet and the length equals to
12 feet? - 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? - Answer -In round columns
Control joints in sidewalks should be spaced at what intervals? - 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: - Answer -95 lbs
How many cubic yard of concrete is required for a 4" slab with the diameter of 15 feet? -
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: - 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? - 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? - Answer -Never
Tensile strength in concrete is achieved by: - 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? - 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? -
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? - Answer -In most cases the most important is the bond.
What is the purpose of the rebar? - Answer -To increase the tensile strength
