ETL 1110-3-496
15 Dec 98
"The water demand is very, very high, around 100 gallons per cubic yard. This would present
a problem in hauling material to a job site. You would have to put most of the water in the load
at the batch plant; you would not have enough water on the truck to add it on site. Therefore you
would have to cut back on your load size, which would increase your costs."
"The air-entraining agent demand is very high, about 46 times that of CLSM using sand as the
aggregate. Without air the mix lack cohesiveness, water migrates to the top immediately, and the
material does not flow well at all. As soon as it stops moving it settles right in and does not move
at all. Adding these high doses of air-entraining agent is very costly. If good flowability is not
required and segregating material will not be a problem you could use this product in those
applications."
Comments regarding sand mix designs (Mix #s 9-16):
"A mix out of this group is what we would normally supply to a job. A mix using washed sand,
cement and Darex IITM would be the least disruptive for us to supply. These materials are always
in our batch plant."
"You can use a non-ASTM material such as sand fill which we have done in the past, but you
take the risk of contaminating other aggregates. Depending on the type of material you may have
trouble getting it out of the bin. We had to use a bin vibrator and in some cases shovel non-
standard material down through the batch plant, which can be dangerous."
"The water demand is a little higher than normal concrete, but not too high to cause problems
with batching or mixing."
"By putting in 5-10 times the normal dosage rate of air-entraining agent (Darex IITM), you can
achieve 15-20% air content, this is economical ... . By using DaraFillTM you can increase your
load size because you do not need to haul the mix as wet. DaraFillTM gives you water reduction
and higher air contents (25%)."
Comments regarding sand and fly ash mix designs (Mix #s 17-24):
"Fly ash has not been readily available in our area until recently."
"A lot of our batch plants are equipped with only one silo which makes it impossible to use fly
ash."
"Fly ash is cheaper than cement but the material we are using now comes from a distant source
and trucking is expensive."
"Fly ash increases the air-entraining agent demand, about 3-5 times the normal dosage rate
(Darex IITM). Fly ash does decrease the water demand but in CLSM it is not that great a benefit."
"There are some low quality fly ashes that cannot be used in concrete that would probably
work well in CLSM, but contamination would again be an issue."
d. General Comments. Users of this ETL are encouraged to view the above trial mix designs
and contractor comments as a single, baseline example of the use of the Example Specification of
the previous section. The mix designs themselves are neither encouraged nor discouraged.
However, the underlying process used to developed these designs, based upon the suggestion in
A-10
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