DelDOT Standard Specifications 208: Flowable Fill

208.1Description.

This work consists of providing and placing flowable fill.

208.2Materials.

A.Flowable Fill Section 1047.1

B.Mortar Section 1047.6

C.Submit material sources to the engineer at least 30 calendar days before use.

D.Submit material test data of fly ash, representative of the source, to the engineer at least 30

calendar days before use. Include test data characteristics of the ash leachate as determined by the Toxicity Characteristics Leaching Procedure (TCLP) in accordance with EPA SW-846, with respect to leachate metals.

208.3Construction.

208.3.1 Plant and Equipment Requirements. Provide flowable fill produced only in batching plants in accordance with Section 1022. 208.3.2 Transportation. Transport flowable fill in ready-mix trucks or as approved by the engineer. Place the flowable fill within 3-hours of mixing water with the dry materials. 208.3.3 Placement.

A.Plug downstream pipe end with brick and mortar. Flowable fill the pipe in such a way that both

ends of the pipe are sufficiently plugged upon completion of the work.

B.Place flowable fill only when the ambient temperature is a minimum of 40 degrees F and rising.

C.Place when the temperature of the flowable fill is no less than 50 degrees F.

D.Do not place flowable fill against frozen surfaces.

E.Protect flowable fill from freezing for at least 36-hours in accordance with Section 501.3.6.

F.Discharge fill at a rate that allows the material to:

1.Flow into the placement location;

2.fill all voids; and

3.not dislodge the existing containment or interior items.

G.Ensure that all interior items can withstand the lateral hydraulic pressures of the flowable fill. The

maximum allowable lift is 5-feet deep unless otherwise directed by the engineer. Allow each lift to cure until it is self-supporting before placing additional lifts or other loads.

H.Take care to prevent pipes from floating with the use of straps, soil anchors, or other approved

means of restraint required to ensure proper alignment when using flowable fill as backfill for pipes.

I.Maintain all confining and supporting structures, protective covers, and barriers until the flowable

fill is self-supporting. Shrinkage of the flowable fill as it cures may require additional backfill with other material. Protect flowable fill from direct contact with vehicular traffic and from prolonged exposure to rain or running water.

208.4Method of Measurement.

A.The Department will measure the number of cubic yards of material accepted and placed within

the approved limits of the fill location. The Department will measure pipe trenches in accordance with Section 207.4.

B.The engineer will measure flowable fill for abandoned structures by the truck in accordance with

Section 109.1.

208.5Basis of Payment.

The Department will pay for flowable fill at the contract unit price per cubic yard. Price and payment will constitute full compensation for:

A.Providing flowable fill mixture materials and designing, mixing, and hauling the flowable fill;

B.preparing the fill;

C.anchoring items within the fill; and

D.protecting and curing the fill after placement.

ITEM DESCRIPTION UNIT 208000 FLOWABLE FILL CY

Referenced in this section

Sections that cite this one

FLOWABLE FILL in other states

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Source: Delaware Standard Specifications for Road and Bridge Construction, 2026 Edition. Pages 131–0 of 786. View official source ↗

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207 STRUCTURAL EXCAVATION AND BACKFILLING

209 BORROW

208FLOWABLE FILL

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