Flowable Fill

fill
#1

So today we were asked by a contractor to provide him a specification for Flowable Fill under some footings that were to have over excavation done below them. I’ve always assumed that Flowable Fill was just a general phrase used for a proprietary material.

Do any of you actually specify a design mix or do you just call out a minimum compressive strength?

#2

Jeff: I would just call a local batch plant and ask for their specs for CDF (controlled density fill). These mixes are very flowable and should work well.

#3

From my project notes:

TYPE OF CONST CEMENT MIN F’c MAX SIZE MAX AIR
TYPE AT 28 DAYS AGG SLUMP
(MPa) (in) (in) (%)

CLSM GUb 0.7 3/16 10 4-6

CLSM GUb 1 3/16 10 4-6

CLSM GUb 2 3/16 10 4-6
.
.
.
.
.
CLSM TRIAL MIX PROPORTIONS

MIN CEMENT 50 PCY

MIN FLY ASH (TYPE F) 150 PCY

FLYASH SHALL NOT HAVE A HIGH ALKALI (4.5% MAX), SULPHATE OR REACTIVE MATERIAL CONTENT

FINE AGGREGATE 2700 PCY TO ASTM C33

MAX WATER 290 PCY

CLSM SHALL BE FLOWABLE AND SHOULD NOT BE VIBRATED U/N

The tabular stuff has to be formatted using a non-proportional font.

Dik

#4

Flowable fill is known by a variety of names. It’s official name is “Controlled Low Strength Material (CLSM)” and has both ACI and ASTM standards and recommendations.

Here is a link to a document put out by the National Ready Mix Concrete Association on the design of CLSM.

CLSM/Flowable Fill

#5

Thanks, Ron

Dik