Cel-A-Fill Print

Fly Ash Slurry - Fill Material


This section governs the furnishing of all labor, equipment, tools, and materials and the performance of all work necessary for construction of CELL-A-FILL slurry for filling voids.


Material Control and Quality:

No material shall be used until it has been certified or tested for compliance with specifications approved by the Engineer.


The CELL-A-FILL slurry for use in construction of this fill shall conform to the following requirements.

  • Fly Ash shall be tested in accordance with ASTM C311 and shall conform to ASTM C618, Class C fly ash.
  • Fine aggregate shall conform to ASTM C94.
  • Mixing water shall conform to ASTM C94.
  • Admixtures for retarding the set or for foaming the slurry to reduce the unit weight, can be sued with prior approval by the Engineer.

Handling, Mixing and Proportioning:


The fly ash shall be stored and handled in closed, waterproof containers prior to fill. If storage bins are used, they shall be completely enclosed. Other methods of storage are subject to the approval of the Engineer. Fly ash that has been partially caked or set, shall not be used.

Environmental Limitations:

CELL-A-FILL shall be placed at ambient air temperatures above 20°F.

Composition of the CELL-A-FILL: CELL-A-FILL slurry mixtures shall consist of Class C fly ash and water; or Class C fly ash, a retarder and water; or Class C fly ash, a retarder, a foaming agent and water. The slurry, if specified by the Engineer, shall contain line aggregate.

Mix Design Criteria:

Laboratory test specimen(s) of the CELL-A-FILL mix, combined in proportions of the job mix design, shall be prepared and tested and shall meet the following requirements.

7-Day Compressive Strength ____ PSI (Min)
28-Day Compressive Strength ____ PSI (Max)
Final Set ASTM C266 2 Hrs. Max


pic-cellConstruction Details:

The CELL-A-FILL slurry fill material shall be placed to fill the voids and to the grades shown on the plans, or directed by the Engineer.