CSLB CONCRETE C8 LICENSE PRACTICE TEST
#1 2025-2026 QUESTIONS WITH 100% CORRECT
ANSWERS
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 needPto first
determine the areaPof the circle then multiply it by the length.Traditional MethodUse the following formul
a:Area of the circle = π x r x rWhere πP= 3.14 and radius (r) = 1.5 feet (half of the diameter length)Area =
3.14 x 1.5 x 1.5AreaP= 7.065 sq. ft.Multiply area by the length to find the volume.7.065 x 12 = 84.78Short
cut MethodArea of the circle is 78.5% of the square. Treat the circle as a square and solve for the area.Fin
d 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 = 7.06
5 square feetMultiply area by the length to find the volume.7.065 x 12 = 84.78 cubic feet
WherePare 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 spacedPequal to the width of the slab, but not more tha
n 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 = 3.14Pand 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 d
, epth of the slab (in feet) to find the volume in cubic feet.176.625 x .333 = 58.82 cubic feetConvert cubic f
eet into cubic yards.58.82 ÷P27 = 2.18 cubic yardsSince 2.18 is not a given option, round up the number t
o 2.5 cubic yardsShortcut MethodThis problem can be solvedPusing a much simpler method. First is to fin
d the area of the square, then convert it into the area of the circle by multiplying it by 78.5%.Area of the s
quare = 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 givenP
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 pip
e? - - 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: = 2A = 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 t
he volume into cubic yards.21322.5 ÷ 27 = 789.72 cubic yards
WhenPcanPthe live load be calculated by multiplying the height, width and length of a pour and dividing b
y 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 s
quare foot? - - CORRECT ANSWER -$6524.90
Explanation:
The easiest way to solve for the area of the slab is to image a full rectangle of thePslab and subtract void ar
eas 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: 1
1.5' x 1.83' = 21.045 sq ftRight void area: 9.167' x 15' = 137.505Net areaPof the foundation slab: 2013.94
- 12.2 - 21.045 - 137.505 = 1843.19 sq ft.Calculate thePprice of the slab.1843.19 sq ft x $3.54 = $6524.90
#1 2025-2026 QUESTIONS WITH 100% CORRECT
ANSWERS
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 needPto first
determine the areaPof the circle then multiply it by the length.Traditional MethodUse the following formul
a:Area of the circle = π x r x rWhere πP= 3.14 and radius (r) = 1.5 feet (half of the diameter length)Area =
3.14 x 1.5 x 1.5AreaP= 7.065 sq. ft.Multiply area by the length to find the volume.7.065 x 12 = 84.78Short
cut MethodArea of the circle is 78.5% of the square. Treat the circle as a square and solve for the area.Fin
d 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 = 7.06
5 square feetMultiply area by the length to find the volume.7.065 x 12 = 84.78 cubic feet
WherePare 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 spacedPequal to the width of the slab, but not more tha
n 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 = 3.14Pand 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 d
, epth of the slab (in feet) to find the volume in cubic feet.176.625 x .333 = 58.82 cubic feetConvert cubic f
eet into cubic yards.58.82 ÷P27 = 2.18 cubic yardsSince 2.18 is not a given option, round up the number t
o 2.5 cubic yardsShortcut MethodThis problem can be solvedPusing a much simpler method. First is to fin
d the area of the square, then convert it into the area of the circle by multiplying it by 78.5%.Area of the s
quare = 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 givenP
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 pip
e? - - 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: = 2A = 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 t
he volume into cubic yards.21322.5 ÷ 27 = 789.72 cubic yards
WhenPcanPthe live load be calculated by multiplying the height, width and length of a pour and dividing b
y 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 s
quare foot? - - CORRECT ANSWER -$6524.90
Explanation:
The easiest way to solve for the area of the slab is to image a full rectangle of thePslab and subtract void ar
eas 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: 1
1.5' x 1.83' = 21.045 sq ftRight void area: 9.167' x 15' = 137.505Net areaPof the foundation slab: 2013.94
- 12.2 - 21.045 - 137.505 = 1843.19 sq ft.Calculate thePprice of the slab.1843.19 sq ft x $3.54 = $6524.90
