LD2_SCC_SOW_30OCT2023.pdf

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LOCK AND DAM NO. 2

WINTER MAINTENANCE – DEWATERING

CONCRETE SUPPLY AND DELIVERY

1. GENERAL

The work shall consist of the concrete being supplied for Lock 2 Winter Maintenance. The placement area includes options for vertical concrete repair placements along the Land and River wall inside the lock chamber.

The quote shall provide for all labor, equipment, materials, and supplies necessary for this work.

2. CONSTRUCTION SCHEDULE

114 CY of concrete shall be supplied for vertical wall repair placements. Placement can begin any time after submittal approval and shall be completed by 8 March 2024. The contractor should coordinate the delivery date and time with the Government representative identified at contract award.

3. DELIVERY

The Government may require up to 19 deliveries with a minimum of 6 cubic yards (CY) of concrete per placement. Note the number of deliveries is dependent on the volume of concrete required for each placement.

After each truck has been fully discharged the drum and chutes will be washed into a government supplied onsite waste container. The Government will notify the contractor a minimum of 2 business days prior to the need for the additional concrete delivery.

4. SITE LOCATION

Lock and Dam No. 2 U.S. Army Corps of Engineers 1350 Lock and Dam Road Hastings, MN 55033-1145

5. SUBMITTALS

The following shall be submitted to the Government for approval no later than 10 days after the award of contract.

1. CONCRETE MIXTURE DESIGN

A mix design shall be submitted for each concrete mix to be used on the project. Each mix design shall list the proportions by weight of cement, weight or volume of water, weights of aggregates in a saturated surface-dry condition, and type, quantity, and name of admixtures per cubic yard of concrete. All materials included in the mixture shall be of the same type and from the same source as will be used on the project.

Each mix shall be accompanied by evidence that demonstrates the mix will produce concrete having the characteristics and quality as specified:

a. MIX DESIGN STUDY

Submit a mix design study complying with ACI 211.1 conducted in the past 12 months. The mix design shall be completed by a testing laboratory complying with ASTM C 1077. For SCC (Self-

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Consolidating Concrete) submit evidence of the design mix for this project. The evidence shall include test data from the Slump Flow Test including the Visual Stability Index (VSI) per ASTM C 1611 and its appendix. A registered professional engineer knowledgeable and familiar with self-consolidating concrete mixes shall conduct these tests or have them done under his immediate supervision.

b. PROJECT DATA

Project data or mix design studies shall be obtained for the exact mix as submitted. Minor mix alterations or substitutions may be accepted if approved by the Contracting Officer. Any alternations or substitutions shall be clearly identified and shall be accompanied by recommendations from the admixture supplier or a registered professional engineer indicating the expected effects on the concrete.

2. GENERAL CONCRETE REQUIREMENTS

The concrete shall be a self-consolidating concrete (SCC) that is able to flow under its own weight and completely fill the form work, even in the presence of dense reinforcement without the need of any vibration while maintaining homogeneity. The concrete shall be composed of a cementitious material, water, fine and coarse aggregates, and admixtures. The admixtures shall include High Range water reducers

(HRWR), which are an essential component of SCC to provide the necessary work ability; viscosity modifying agents (VMA) for stability and air entraining admixtures (AEA) to improve the freeze-thaw resistance. The design compressive strength as determined by ASTM C 39 shall not be less than 5,000 pounds per square inch in 28 days. The water-cementitious (w/cm) ratio shall be within the range of 0.30 to

0.45. The maximum water-cementitious ratio will be determined by the weight equivalency method as described in ACI 211.1 (cement plus pozzolan, and silica fume). This w/cm ratio may cause higher strengths than required. The cementitious material content shall be a minimum of 500 and a maximum of

800 pounds per cubic yard. See ACI 237 Self Consolidating Concrete for more information. Materials shall meet the requirements of the respective publications and other data specified below.

a. SLUMP FLOW:

For SCC (self-consolidating concrete) the slump flow of concrete is identified as the flow of concrete as measured by the Slump Flow Test. The slump flow should be between 24 and 30 inches, with a visual rating of static stability equal to zero or one as determined by the Visual Stability Index (VSI) as described in ASTM C 1611 and its appendix.

b. ADMIXTURES:

Admixtures to be used on the project shall be included in the mix design submittals. Accelerating admixtures shall be used only when approved in writing.

c. AIR ENTRAINMENT:

All concrete shall be air entrained to contain between 4-1/2 and 7-1/2 percent total air.

d. SIZE OF COARSE AGGREGATE:

Nominal maximum size coarse aggregate shall be 3/4-inch.

e. FIBERS

A synthetic fiber shall be added to the mixture to reduce early-age cracking and cracks induced by restraint or temperature.

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f. CONCRETE TEMPERATURE:

When the ambient temperature during placing is 40 °F or less, or is expected to be at any time within 6 hours after placing, the temperature of the concrete as delivered shall be between 55 and 65 °F.

g. CEMENTITIOUS MATERIALS:

Cementitious materials shall be portland cement, or portland cement in combination with pozzolan and

Silica Fume. Optional pozzolan replacement of cement shall be limited to 25 percent of the total cementitious material of a mix by weight. Optional Silica Fume replacement of cement shall be limited to 5 percent of the total cementitious material of a mix by weight. Cementitious materials shall conform to appropriate specifications listed below. Use of cementitious materials in concrete which will have surfaces exposed in the completed structure shall be restricted so there is no change in color, source, or type of cementitious material.

i. Portland Cement:

ASTM C 150, Type I or Type II.

ii. Portland Limestone Cement:

ASTM C 595, Type IL with 5-15% limestone is permitted.

iii. Pozzolan (Fly Ash):

ASTM C 618, Class C or F with the optional requirements for multiple factors, drying shrinkage, and uniformity from Table 3 of ASTM C 618.

iv. Silica Fume:

Silica Fume conforming to ASTM C1240.

h. AGGREGATES:

i. Composition:

Fine aggregate shall consist of natural sand, manufactured sand, or a combination of natural and manufactured sands. Coarse aggregate shall consist of gravel, crushed gravel, crushed stone, or a combination thereof.

ii. Quality:

The aggregate particles shall be clean, hard, unweathered, and uncoated. The shape of the particles shall be generally cubical or spherical. Where required, fines shall be removed from the aggregates by adequate washing. The aggregates as delivered to the mixer shall meet the quality requirements of ASTM C 33, table 3 for the appropriate type or location of concrete construction for use in a severe climate.

i. CHEMICAL ADMIXTURES

Chemical admixtures, when required or permitted, shall conform to the appropriate specification listed.

i. Air-Entraining Admixture.

ASTM C 260 and shall consistently entrain the air content in the specified ranges under field conditions.

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ii. Accelerating Admixture.

ASTM C 494, Type C or E, except that calcium chloride or admixtures containing calcium chloride shall not be used.

iii. Water-Reducing or Retarding Admixture.

ASTM C 494, Type A, B, or D.

iv. High-Range Water Reducer.

ASTM C 494, the admixture shall be a Polycarboxylate-based HRWRA, Type F or G, except that the six-month and one-year compressive strength test requirements are waived.

v. Viscosity-Modifying Admixture.

The Viscosity-modifying admixture shall be a commercial formulation specially developed for producing concrete with enhanced viscosity controlling properties that when used with a high-range water reducing admixture will produce a self-compacting concrete.

j. FIBERS

Fibers, when required or permitted, shall conform to the appropriate specification listed.

i. Synthetic Fibers

Monofilament Polypropylene Concrete Microfiber that meets the requirements of ASTM C-1116, Type III.

6. SAFETY

All work shall be in conformance with the latest version of the Corps of Engineers Safety and Health

Requirements Manual EM 385-1-1.

7. SITE RESTORATION AND CLEANUP

The contractor shall clean up and dispose of all job-related debris in accordance with all Federal, state, and local laws, ordinances, and regulations. All surface areas damaged by the Contractor’s operations shall be restored.

8. MEASUREMENT AND PAYMENT

Payment shall constitute full compensation for furnishing all labor, materials, equipment, and incidentals required and performing all work in a satisfactory manner and in accordance with the requirements described herein.

All invoices shall be sent to: A copy of all invoices shall be sent to:

USACE Finance Center Fountain City Service Base St Paul District (B6) Attn: Jamie Mercer 5722 Integrity Drive PO Box 397 Millington, TN 38054-5005 431 North Shore Drive Fountain City, WI 54629-0397