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C-30HD — PARTS & OPERATION MANUAL — REV. #4 (03/06/01) — PAGE 19
CONCRETE MIX DESIGNS-SCREEN ANALYSIS-
TERMINOLOGY
The following information has been prepared to assist in the
selection of concrete mix designs in certain areas where the
use of concrete pumps is a new industry.
The result of years of experience by many concrete pump
users and aggregate suppliers has proven the importance of
certain requirements necessary to successful concrete
pumping. The strength and quality of the concrete is relative
to the cement/water ratio and the type of gradation of the
aggregates used.
Special emphasis is given to the gradation of the fine
aggregates, coarse aggregates sand and used in all pump
mixes. Generally speaking, if the screen analysis of the local
sand and rock conform to the A.S.T.M. specifications shown
on Pages and 13 and the proper ratio of sand and rock are
used in the mix, you can expect a pumpable mix.
If difficulty is experienced in pumping the mixes shown on
Pages 11 and 12, consult your local aggregate supplier with
this information and make the necessary adjustments.
CONCRETE MIX INFORMATION
DEFINITIONS
ONE SACK CEMENT (U.S.)-94lbs. (42.58 KG)
S.S.D.-Saturated Surface Dry: Meaning sand particles may
be saturated with moisture but there is no free water on the
surface.
OVEN DRY-meaning all the moisture is removed from the sand
particle.
SLUMP-a measure of moisture consistency.
W/C SAND-washed concrete sand.
#4 GRAVEL or ROCK-3/8” PEA GRAVEL (1/2” MINUS)
#3 GRAVEL or ROCK-3/4” rock (1” minus)
POZZOLITH-Master Builders Admixture -(Pozz)
P.S.I.-compressive strength (Pounds per Square Inch)
DEFICIENCIES IN SIEVE ANALYSIS of AGGREGATES
The uniform gradation of sand and aggregate in the concrete
mix is extremely important in all pumping operations. It is highly
possible that the lack of certain sieve sizes may prevent
pumpability. In some areas it may be necessary to make up
these deficiencies by the addition of “blending sands” to the
local sand.
GENERAL RULE-supplement to improve pumpability.
FLY ASH-use up to 15% of cement weight.
POZZOLIN-use up to 13% of cement weight.