SECTION 03123 CONTROLLED DENSITY FILL

SECTION 03123

_{CONTROLLED DENSITY FILL}

PART 1 - GENERAL

1.1 SUMMARY

A. Section Includes:

1. Controlled Density Fill (CDF) is a flow-able mixture of aggregate and cementitious material used in lieu of compacted fill and it is also called on the drawings as “lean concrete”.

B. Related Specification Sections include but are not necessarily limited to:

1. Section 03300, Cast-in-Place Concrete

2. Section 03350, Concrete Testing

1.2 DEFINITIONS

A. Controlled Density Fill (CDF) and Controlled Low Strength Materials (CLSM) are synonymous.

B. CDF: a flow-able, self-leveling and self-compacting backfilling material. It consists of a mixture of aggregate and cementitious materials containing sufficient Portland cement to develop a 28-day compressive strength of between 50 and 150 pounds per inch.

_{C. Flowability: Material Property which relates to the rheology of the material.}

D. Excavatability: Material Property which relates to the ease with which the material can be removed.

E. Permeability: Material property which relates to the ease with which gases and liquids pass through the material.

F. Density: Material property which relates to the unit weight or mass of the materials.

G. Strength: Material Property that relates to the ability of hardened material to support gravity loads or stresses at a given age.

H. CDF Air Entraining Admixture: A chemical admixture specially formulated to entrain air into the CDF.

I. Hardening Time-Period of time for CDF mixtures to reach a state in which it will support a specified load.

J. Subsidence and Settlement: The reduction in initial in-place volume caused by the displacement of water and release of entrapped air as a result of consolidation.

K. pH: CDF property that is a measure of alkalinity or acidity.

1.3 QUALITY ASSURANCE

A. Referenced Standards:

1. Building Code:

a. California Building Code and associated standards, 2010 edition, including all amendments referred to here in as Building Code.

2. American Concrete Institute (ACI):

a. Controlled Low-Strength Material SP-150, 1994.

b. State of the Art Report on Controlled Low-Strength Materials, Committee

229, 1994.

3. ASTM International (ASTM):

a. C403, Time of Setting of Concrete Mixtures by Penetration Resistance b. D1883, California Bearing Ratio.

c. D4832, Preparation and Testing of Controlled Low Strength Material Test

Cylinders

d. D508, Measurement of Hydraulic Conductivity of Saturated Porous Materials

Using a Flexible Wall Permeameter.

e. C5971, Sampling Freshly Mixed Controlled Low Strength Material. f. D6103, Flow Consistency of Controlled Low Strength Material.

g. D6023, Unit Weight, Yield, Cement Content and Air Content (Gravimetric) of

Controlled Low Strength Material

h. D6024, Ball Drop on Controlled Low Strength Material to Determine

Suitability for Load Application. B. Quality Control:

1. Concrete testing agency:

a. CONTRACTOR to employ and pay for services of a testing laboratory to:

1) Perform materials evaluation.

2) Design CDF mixes.

b. Concrete testing agency to meet requirements of ASTM E329.

2. Do not begin concrete production until proposed CDF mix design has been accepted by ENGINEER.

a. Acceptance of CDF mix design by ENGINEER does not relieve CONTRACTOR of its responsibility to provide CDF that meets the requirements of this Specification.

3. Adjust CDF mix designs when material characteristics, job conditions, weather, strength test results or other circumstances warrant.

4. Perform structural calculations as required to prove that all portions of the structure in combination with remaining forming and shoring system has sufficient strength to safely support its own weight plus the loads placed thereon.

C. Qualifications:

1. Ready mixed concrete batch plant certified by National Ready Mixed Concrete

Association (NRMCA).

2. Shoring of walls or wall forms adjacent to CDF placements shall be checked and designed by a professional engineer currently registered in the state of California.

1.4 SUBMITTALS

A. Shop Drawings:

1. Prior to the start of CDF placement, submit a CDF mix design proposed for use. Based on the submittal, ENGINEER may require the CONTRACTOR to submit appropriate laboratory or field test data documenting compliance of specified material with properties specified herein.

1.5 DELIVERY, STORAGE, AND HANDLING A. Storage of Material:

1. Cement and fly ash:

a. Store in moisture-proof, weather-tight enclosures. b. Do not use if caked or lumpy.

2. Aggregate:

a. Store to prevent segregation and contamination with other sizes or foreign materials.

b. Obtain samples for testing from aggregates at point of batching. c. Do not use frozen or partially frozen aggregates.

d. Do not use bottom 6 inches of stockpiles in contact with ground. e. Allow sand to drain until moisture content is uniform prior to use.

3. Admixtures:

a. Protect from contamination, evaporation, freezing, or damage.

b. Maintain within temperature range recommended by manufacturer. c. Completely mix solutions and suspensions prior to use.

B. Delivery:

1. CDF:

a. Prepare a delivery ticket for each load for ready-mixed concrete.

b. Truck operator shall hand ticket to ENGINEER at the time of delivery. c. Ticket to show:

1) Mix identification mark.

2) Quantity delivered.

3) Amount of each material in batch.

4) Outdoor temp in the shade.

5) Time at which cement was added.

6) Numerical sequence of the delivery.

7) Amount of water added.

PART 2 - PRODUCTS

2.1 ACCEPTABLE MANUFACTURERS

A. Subject to compliance with the Contract Documents, the following products and manufacturers are acceptable:

1. Form coating:

a. Richmond "Rich Cote".

b. Industrial Lubricants "Nox-Crete Form Coating". c. Euclid Chemical "Eucoslip VOX".

d. Or Equal.

B. Submit request for substitution in accordance with the General Requirements.

2.2 MATERIALS

A. Portland Cement: Conform to ASTM C150 Type II or Type V.

B. Fly Ash:

1. ASTM C618, Class F or Class C.

2. Maximum Loss on Ignition: 4 percent.

_{3. Compatible with other concrete ingredients.}

C. Admixtures:

_{1. Air Entraining Admixtures: ASTM C260.}

2. Water reducing, retarding, and accelerating admixtures:

a. ASTM C494 Type A through E.

b. Conform to provisions of ACI 212.3R.

c. Do not use retarding or accelerating admixtures unless specifically accepted in writing by ENGINEER and at no cost to OCSD.

d. Follow manufacturer's instructions. e. Use chloride free admixtures only.

3. Maximum total water soluble chloride ion content contributed from all ingredients of concrete including water, aggregates, cementitious materials and admixtures by weight percent of cement:

a. 0.10 all concrete.

4. Do not use calcium chloride.

5. Pozzolanic Admixtures: ASTM C618.

6. Provide admixtures of same type, manufacturer and quantity as used in establishing required concrete proportions in the mix design.

_{D. Water: Potable, clean, free of oils, acids and organic matter.}

E. Aggregates:

1. Normal Weight Concrete: ASTM C33, except as modified below.

_{2. Fine aggregate:}

a. Clean natural sand.

b. No manufactured or artificial sand.

3. Coarse aggregate:

a. Crushed rock, natural gravel, or other inert granular material. b. Maximum Amount of Clay or Shale Particles: 1 percent.

4. Gradation of coarse aggregate:

a. Lean Concrete and Concrete Topping: Size #8. b. All Other Concrete: Size #57 or #67.

2.3 CDF MIXES A. General:

1. All CDF to be ready mixed and supplied by a concrete supplier experienced in the production of such fill material. Mix design shall be in accordance with ACI Committee 229 report ‘Controlled Low Strength Materials’.

2. Provide concrete of specified quality capable of being placed without segregation and, when cured, of developing all properties required.

3. All concrete to be normal weight concrete. B. Strength:

1. Provide specified strength and type of CDF for each use in structure(s) as follows:

T ype	Weight	Specified Strength*
Non-Excavatable CDF	Normal weight	100 pounds per inch
Excavatable CDF**	Normal weight	50 pounds per inch

*Unconfined Compressive Strength.

**Excavatability shall be evaluated on the basis of past performance and experience. When past performance records are not available, excavatability shall be evaluated on the basis of unconfined compressive strength tested in accordance with ASTM D4832. Excavatable CDF shall have a minimum strength of 30 pounds per inch.

C. Air Entrainment:

1. Provide air entrainment in all concrete resulting in a total air content of 6 to 8 percent by volume.

2. Air content to be measured in accordance with ASTM C231, ASTM C173, or

ASTM C138.

3. Flow-ability normal flow-able material shall have a flow of 6 to 8 inches tested in accordance with ASTM D6103. Low flowable material shall have a flow of 6 inches. High flowable materials shall have a minimum flow of 8 inches.

D. Selection of Proportions:

1. General:

a. Proportion ingredients to:

1) Produce proper workability, durability, strength, and other required properties.

2) Prevent segregation and collection of excessive free water on surface.

2. Substitution of Fly Ash: Maximum of 25 percent by weight of cement at rate of 1

_{LB fly ash for 1 LB of cement.}

3. Sand cement grout:

a. Three parts sand.

b. One part Portland cement.

_{c. Entrained Air: Six percent plus or minus one percent.}

d. Sufficient water for required workability.

e. Minimum 28-Day Compressive Strength: 50 pounds per inch.

_{PART 3 - EXECUTION}

3.1 FORMING AND PLACING CONCRETE A. Placing Concrete:

1. Place concrete in compliance with ACI 304R and ACI 304.2R.

2. Place in a continuous operation within planned joints or sections.

3. Begin placement when work of other trades affecting concrete is completed.

4. Place concrete by methods which prevent aggregate segregation.

5. Do not allow concrete to free fall more than 4 feet. B. Curing:

1. Begin moisture curing concrete or using curing compound as soon as free water has disappeared from exposed surfaces.

2. Curing compounds shall be water based resin curing compounds.

3. Provide protection as required to prevent damage to concrete and to prevent moisture loss from concrete during curing period.

C. Broom Finish: Immediately after concrete has received a float finish as specified, give it a transverse scored texture by drawing a broom across surface.