GUNITE - SHOTCRETE - CONCRETE
STRUCTURAL REINFORCEMENT – REBAR
Pneumatically applied concrete “Shotcrete” wet, or “Gunite” dry, allows unlimited freedom of design of
swimming pool shape, size and water features. Swimming pool Shell Thickness and amount and size of
reinforcing steel (REBAR) can be adjusted to meet STRUCTURAL REQUIREMENTS which vary with design, soil
conditions and temperature.
Concrete PSI – Compressive strength of concrete is a physical property and is expressed in pounds per
square inch (psi) at an age of 28 days. Most general use concrete has a compressive strength between
3000 psi and 5000 psi.
Swimming Pool cubic yard gunite requirement
Example 15′ x 30′ freeform pool 3′ to 6′ deep w/ 80 perimeter and 390 square ft..
Pool 3′ + 6′ = 9′ divided by 2 = 4.5′ average depth x 80′ perimeter = 360 sf walls.
390 floor sf + 360 wall sf = 750 square ft. total.divide by 2 (walls are 6″ thick) = 375.
375 divided by 27 (cu. ft. per cu. yd.) =14 add 2 yards for beam and 3 yards for
steps and benches = 19 cubic yards plus or minus.
Concrete = 142.4 lbs. per cubic ft. – 3844 lbs. per cubic yard
Soil = 120 lbs. per cubic ft. – 3240 lbs. per cubic yard
Water = 62.4 lbs. per cubic ft. – 1496 lbs. per cubic yard
The larger the agregate present in the cement the lighter the weight.
Rebar – 1/8″ to 2-1/2″ in 1/8″ increments.
#3 Rebar = 3/8″
#4 Rebar = 4/8″ or 1/2″
#5 Rebar = 5/8″
Bend – cold only.
Bend – Inside diameter of bend shall not be less than 4db or 4 x diameter of bar.
Cover (concrete) of reinforcement steel minimums shall be 2″ to water and 3″ to soil.
Rebar (steel reinforcement) used in swimming pools is
commonly known as “intermediate grade 60”.
SEE PLAN – STEEL REINFORCEMENT (REBAR) SCHEDULE AND REBAR FORMULA
TO COMPUTE STEEL REQUIREMENTS
Overlap rebar (joints) @ 48 times diam.
Example #5 rebar @ x48 = 30″ overlap.
Example #4 rebar @ x48 = 24″ overlap.
Example #3 rebar @ x48 = 18″ overlap.
Rebar is usually sold by weight (tons) and in 20′ or 40′ lengths. When possible use 40′ lengths for
fewer overlaps (joints) and lower cost.
The American Concrete Institute refers to all pneumatically placed concrete as shotcrete.
Shotcrete refers to both application methods – wet or dry.
Concrete for Swimming Pool Construction can be Pneumatically applied, Formed
and poured in place or hand stacked.