36C78618B0210-006.pdf

11-01-16

FLOWABLE FILL

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SECTION 31 23 23.33

FLOWABLE FILL

PART 1 - GENERAL

1.1 SUMMARY

A. Section Includes:

1. Cementitious slurry used as fill or backfill in lieu of compacted earth.

1.2 DEFINITIONS

A. Flowable Fill: Ready-Mix Controlled Low Strength Material used as an alternative to compacted soil, and is also known as controlled density fill, and several other names, some of which are trademark names of material suppliers. Flowable fill (Controlled Low Strength Material) differs from Portland Cement concrete as it contains low cementitious content to reduce strength development for possible future removal.

Design strength for this permanent type flowable fill is 2.1 MPa

(300 psi) minimum compressive strength at 28 days. Chemical admixtures may also be used in flowable fill to modify performance properties of strength, flow, set and permeability.

B. Excavatable Flowable Fill: Flowable fill designed with compressive strength that will allow excavation as either machine tool excavatable at maximum compressive strength of 1.5 MPa (200 psi) at 1 year, or hand tool excavatable at maximum compressive strength of 0.7 MPa (100 psi) at 1 year.

1.3 APPLICABLE PUBLICATIONS

A. Comply with references to extent specified in this section.

B. American Concrete Institute (ACI):

1. 229R-13 - Report on Controlled Low-Strength Materials.

C. ASTM International (ASTM):

1. C33/C33M-16 - Concrete Aggregates.

2. C39/C39M-16 - Compressive Strength of Cylindrical Concrete

Specimens.

3. C150/C150M-16 - Portland Cement.

4. C260/C260M-10a - Air-Entraining Admixtures for Concrete.

5. C494/C494M-15a - Chemical Admixtures for Concrete.

6. C940-16 - Expansion and Bleeding of Freshly Mixed Grouts for

Preplaced-Aggregate Concrete in the Laboratory.

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1.4 SUBMITTALS

A. Flowable Fill Mix Design: Provide mix design containing cement and water. At Contractor’s option, it may also contain fly ash, aggregate, or chemical admixtures in any proportions such that final product meets specified strength and flow consistency and shrinkage requirements.

B. Certificates: Certify products incorporated in flowable fill, following achievement of the required strength, do not represent a threat to groundwater quality.

1.5 FIELD CONDITIONS

A. Environment:

1. Weather Limitations: Install flowable fill only when approved in advance by COR and when existing and forecasted weather conditions are within limits established by manufacturer of materials and products used.

PART 2 - PRODUCTS

2.1 SYSTEM DESCRIPTION

A. Flowable Fill: Fluid that sets within required time and, after curing, obtains desired strength properties as evidenced by laboratory testing of specific mix design, at locations shown on drawings. Flowable fill for use as structural fill to remain permanently.

2.2 PRODUCTS

A. Provide each product from one manufacturer. If not otherwise specified, comply with ACI 229R recommendations.

1. Portland Cement: ASTM C150/C150M, Meeting Missouri State DOT standards.

2. Mixing Water: Fresh, clean, and potable.

3. Air-Entraining Admixture: ASTM C260/C260M.

4. Chemical Admixtures: ASTM C494/C494M.

5. Aggregate: ASTM C33/C33M.

2.3 MIXES

A. Flowable Fill Mix: Provide minimum cementitious materials and water.

Cementitious materials to be portland cement, pozzolanic materials, or other self-cementing materials, or combinations thereof, at

Contractor’s option, provided certification of no degradation of groundwater quality has been submitted. Flowable fill mix design may also contain, fine aggregate or filler, and chemical admixtures in any

31 23 23.33 - 3 proportions for final product to meet specified strength, flow consistency and shrinkage requirements.

1. Mix Design: Consistency that at time of placement does not require manual means for placement.

2. Minimum Strength: 2.1 MPa (300 psi) according to ASTM C39/C39M at 28 days after placement.

3. Minimum Subsidence and Bleed Water Shrinkage: Bleed water evaporation to result in maximum 10.4 mm per m (1/8 inch per foot) shrinkage of flowable fill depth (for mixes containing high fly ash content), as measured in ASTM C940 Section 10.

B. In-Place Yield: Minimum 75 percent of design yield for permanent type.

C. Provide equipment as recommended by manufacturer and comply with manufacturer’s instructions for addition of additives, at production plant or before placement at project site.

PART 3 - EXECUTION

3.1 PREPARATION

A. Examine and verify substrate suitability for product installation.

3.2 FLOWABLE FILL APPLICATION

A. Secure tanks, pipes and other members to be encased in flowable fill.

Ensure that no exposed metallic pipes, conduits, or other items will be in contact with flowable fill after placement. If so, replace with non-metallic materials or apply manufacturer's recommended coating to protect metallic objects before flowable fill placement. Replacement or protection of metallic objects is subject to COR approval.

3.3 PROTECTION

A. Protect exposed surfaces of flowable fill from premature drying, wash by rain or running water, wind, mechanical injury, and excessively hot or cold temperature, by curing method subject to COR approval.

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