Flowable Fill

ERDC TN-DOER-C12

February 2000

Flowable Fill: Flowable fill is any semiliquid blend of dredged material, residual waste material,

and binders that forms a slurry that can be poured into a cavity or structural form and solidifies

rapidly into a cementitious-like material. To evaluate the potential for producing flowable fill in a

particular location, local sources and types of residual waste materials will need to be identified.

Residual waste materials can be in many forms, such as foundry sand, slag, waste glass, stone dust,

fly ash, gypsum, spent lime, etc. The quality, quantity, and availability of these materials must be

determined. Flowable fill could be used to produce construction fill for most construction needs.

Figurines and statues could be made from flowable fill.

Characterization tests of the dredged material should be conducted in accordance with Winfield and

Lee (1999) and Lee (1999). Preliminary tests of blends of the dredged material, available waste

materials, and binders should be conducted. Various commercial entities that have patented

formulations or proprietary processes can conduct appropriate tests.

Results of the characterization and preliminary tests should be presented to local authorities for their

review, comment, and approval as a potential acceptable product. There are no universal contami-

nant concentration standards for construction fill that are acceptable in all situations. A number of

states have or are attempting to establish acceptable contaminant screening levels for some soil

materials used for residential and industrial purposes. The basis for these screening levels varies

from state to state. In some cases, background concentrations of contaminants in typical local soils

are considered, while other screening levels are related to risk assessments. Concerns have been

raised regarding the environmental safety of construction fills that may contain contaminants. The

leachability and migration of contaminants out of the fill and into the environment have been

questioned. Some leachate testing of the flowable fill could be conducted to provide supportive

data for the environmental safety of the product. Controls for such testing would most likely be

locally available construction fill. Risk assessments of the manufactured construction fill and its

use can also be conducted to support the potential safe use of the product. In either case, local

regulatory authorities will decide the acceptability of the flowable fill and its uses for any and all

construction purposes. Coordination with local entities, such as municipal, county, State, and

Federal agencies, that have requirements for building blocks or similar products should be conducted

to identify potential markets. A commercialization plan should be developed using available

resource materials. Participants in the development of the commercialization plan will vary from

location to location. Participants can be, but are not limited to, commercial entities that have

appropriate proprietary technology or a licensed entity, sources of available residual waste materials,

and other interested entities. The plan should then be submitted to the appropriate entity(ies) with

authority over the dredged material to be reclaimed.

Issues that may require resolution prior to implementation can be, but are not limited to, real estate

issues of ownership of the dredged material and/or confined placement facility where the dredged

material is stored; fees to the owner of the dredged material required for the removal of dredged

material; fees to the contractor for the removal of the dredged material; mechanisms used to

implement a commercialization plan such as contract or bidding or sole source contract; technology

licensing mechanisms such as who is required to obtain the license; liability for products produced

and/or uses of the dredged material derived products; acquisition of any and all appropriate permits

that may be required; and any warrantees and quality assurances for successful performance of

manufactured products.