Owner`s manual

23
Keep loads to 3-5 yards when possible. Water content required to maintain slump will vary
according to moisture content in the aggregate. Larger loads and/or higher air temperatures
may require more water to maintain slump. Add water at job site only. Work materials to dry
side. Retardant admixture should be used at the manufacturers recommended minimum
amount. This amount may be adjusted based on local conditions. Air entrainment should be
added at approximately 5%. This amount may be adjusted based on local conditions.
B. Asphalt Curb Mix:
1) Components of One (1) Ton of Asphalt Curb Mix:
a) Liquid Asphalt: Asphalt Content should be 6.0 to 9.0% by weight of total mix
Liquid Asphalt should be AC-20 or AR-8000 (60-70 penetration). The liquid asphalt
content will also have to be raised if the mix has slag, or other absorptive
materials in it.
b) Aggregates: All aggregates must be heated and dried. Crushed aggregates produce
stronger Curb Mixes and have better standing properties when extruding taller curbs
than round river stone. A good starting point is an aggregate blend having 60% sand
and 40% stone.
When extruding curb forms with 8” or 10” augers some of the 3/8” stone can be
replaced with larger stone up to ¾”/ #57. If excessive voids appear on the surface of
the extruded curb, reduce the size of the larger stone (not the %) until the curb
surfaces improves.
Aggregate graduation
SIEVE SIZE PASSING % BY WEIGHT
½” 100
3/8” 75-100
No. 4 60-80
No. 8 45-60
No. 50 18-30
No. 200 2-15
c) Temperature: optimum working temperature needs to be 250 to 290 degrees
Fahrenheit. Under no circumstances should mix temperatures exceed 300 Degrees F.