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Materials Specs

Precast Concrete is a mixture of cement, aggregates and mineral colors and is reinforced with steel.

DESIGN MIX
We use 2 parts gravel, 2 parts concrete sand, and 1 part cement for most mixes. The water content is limited to make the mix stiff. The workability of the concrete is dependant on vibration.

CEMENT
Portland Cement Type I/II gray and/or white comforming to ASTM C-150.

COURSE AGGREGATE
Carefully graded and washed gravel or stone conforming to ASTM C-33. Usual mix gravel does not exceed 3/8 inch. Gradation may vary to achieve desired finish and texture.

FINE AGGREGATE
Carefully graded and washed natural concrete sand conforming to ASTM C-33. Gradation may vary to achieve desired finish and texture.

COLOR
Bayferrox inorganic, synthetic iron oxide pigments, lime proof, and non-fading, conforming to ASTM C-979. Amount of pigment shall not exceed 10% by weight of the cement used.

ADMIXTURES
ASTM C-494

WATER
Potable water free from impurities.

AIR ENTRAINMENT
Wet cast mixture maintains 5-7% air entrainment where surfaces are exposed to freeze-thaw. Admixture conforms to ASTM C-260.

REINFORCING STEEL
Conforms to ASTM 615 and deformations conform to ASTM M-305. Most common is M13 #4, Grade 60 rebar, and 1/4 inch HR round steel.

STRENGTH
Comprehensive strength of 4,000 to 6,000 psi at age 28 days depending on mixture and additives, as determined by tests of 6 inch cylinders.