03 30 00.50.pdf

Charleroi Locks and Dam - Upper and Lower Guard Walls

SECTION TABLE OF CONTENTS

DIVISION 03 - CONCRETE

SECTION 03 30 00.50

CONCRETE: PRODUCTION AND TRANSPORT

PART 1 GENERAL

1.1 SUMMARY

1.2 REFERENCES

1.3 SUBMITTALS

1.4 MIXTURE PROPORTIONS

PART 2 PRODUCTS

2.1 CONCRETE

PART 3 EXECUTION

3.1 CONCRETE PRODUCTION

3.1.1 Government-Furnished Concrete

3.1.2 Off-Site Production Facilities

3.1.2.1 Precast Concrete Plant

3.1.3 Delivery of Government-Furnished Concrete

3.1.3.1 Points Of Delivery

3.1.3.2 Concrete Transport

3.1.4 Transporting Equipment

3.1.4.1 Transfer Hoppers

3.1.4.2 Belt Conveyors

3.1.4.3 Tremie Pipes

3.2 TRANSPORTING CONCRETE AT PROJECT SITE

3.3 CONVEYING CONCRETE ON SITE

3.3.1 Transporting by Belt Conveyor

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SECTION 03 30 00.50 Page 1 W911WN-09-B-0004 Revised by Amendment No. 0002

SECTION 03 30 00.50

CONCRETE: PRODUCTION AND TRANSPORT

PART 1 GENERAL

1.1 SUMMARY

This section addresses the basic requirements for transporting concrete from the specified Points of Delivery to the placement location. Concrete to be placed under this contract will be furnished by the Government.

Production of concrete and transporting to the specified Points of Delivery will be the responsibility of the contractor producing the concrete.

1.2 REFERENCES

The publications listed below form a part of this specification to the extent referenced. The publications are referred to in the text by basic designation only.

ASTM INTERNATIONAL (ASTM)

ASTM C 94/C 94M (2009) Standard Specification for Ready-Mixed Concrete

PRECAST/PRESTRESSED CONCRETE INSTITUTE (PCI)

PCI MNL-116 (1999) Manual for Quality Control for Plants and Production of Structural Precast Concrete Products

1.3 SUBMITTALS

Government approval is required for submittals with a "G" designation;

submittals not having a "G" designation are for information only. When used, a designation following the "G" designation identifies the office that will review the submittal for the Government. Submit the following in accordance with Section 01 33 00 SUBMITTAL PROCEDURES:

SD-01 Preconstruction Submittals

Conveying Equipment; G, ED

The methods and description of the equipment proposed for transporting, handling, and depositing the concrete shall be submitted for review 60 days before concrete placement begins.

The data submitted shall include site drawings or sketches with locations of equipment and placement site.

1.4 MIXTURE PROPORTIONS

Concrete mixtures to be furnished by the Government will be in accordance with Section 03 30 00.40 CONCRETE: MIXTURE PROPORTIONING.

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PART 2 PRODUCTS

2.1 CONCRETE

Concrete furnished by the Government will conform to Section 03 30 00.40

CONCRETE: MIXTURE PROPORTIONING.

PART 3 EXECUTION

3.1 CONCRETE PRODUCTION

3.1.1 Government-Furnished Concrete

The concrete batch plant and conveying system have a rated capacity of 150 cubic yards per hour. Coordination between the Contractor, the Contracting Officer, and the contractor producing the concrete for delivery of the concrete shall be as specified in Section 03 30 00.10 CONCRETE: GENERAL REQUIREMENTS. In General, concrete will be produced two shifts per weekas requested, subject to the requirements of Section 03 30 00.10 CONCRETE:

GENERAL REQUIREMENTS, paragraph Coordination of Production and Delivery.

Based on the contract for production of the concrete, the maximum production per shift will be 250 cubic yards, except for productions for the Upper Guard Wall nose cell which will be a maximum of 1,000 cubic yards per shift.

3.1.2 Off-Site Production Facilities

The plant shall provide a batch ticket in accordance with paragraph "Recorder" for each batch of concrete used for the project. Concrete shall be central-mixed or truck-mixed.

3.1.2.1 Precast Concrete Plant

The capacity shall be adequate to produce the required precast units without cold joints or construction joints that are not shown on the drawings. Plants used to fabricate prestressed precast units shall be certified by the Precast/Prestressed Concrete Institute (PCI) in accordance with the PCI Plant Certification Program and PCI MNL-116, and shall be certified for the group and category represented by the element being fabricated. Plants used to fabricate conventionally reinforced precast units shall be certified by PCI or by the National Precast Concrete Association (NPCA). Materials used at off-site production facilities to produce precast concrete shall be approved in accordance with ASTM C 94/C 94M. The materials may be those approved for project site concrete production, or different materials may be submitted for approval and use at off-site production facilities. Washing of coarse aggregate may be waived at the discretion of the Contracting Officer if the contractor can demonstrate that aggregate delivered to the mixer does not contain fines in excess of the aggregate quality requirements or contain deleterious coatings.

3.1.3 Delivery of Government-Furnished Concrete

3.1.3.1 Points Of Delivery

Concrete to be furnished by the Government will be delivered to a point on or near River Wall Monolith R-35 for work downstream of the dam and to a point on or near River Wall Monolith R-8 for work upstream of the dam. The Contractor shall provide catch boxes at transfer points to capture any

SECTION 03 30 00.50 Page 3 spillage and wash water from cleaning his belts.

3.1.3.2 Concrete Transport

Concrete will be conveyed from mixer to the Points of Delivery using the existing conveyor system to the River Wall. The concrete will be conveyed to the Points of Delivery in sufficient time to permit placement by the Contractor within the time limits specified for the particular types of concrete. The Contractor will be required to accept delivery of the concrete at the Points of Delivery and convey it to the placement locations.

3.1.4 Transporting Equipment

Transporting equipment shall be designed, operated, and maintained so that it provides concrete delivery in a volume and speed that is equal to or greater than the existing conveyor and does not cause or permit segregation or loss of material.

3.1.4.1 Transfer Hoppers

Transfer hoppers shall be capable of receiving concrete directly from delivery equipment and shall have conical-shaped discharge features. The transfer hopper shall be equipped with a hydraulically operated gate and with a means of external vibration to effect complete discharge. Transfer hoppers shall be shaded and protected from wind and precipitation.

3.1.4.2 Belt Conveyors

Belt conveyors shall be designed and operated to assure a continuous uniform flow of concrete from mixer to final place of deposit without segregation of ingredients or loss of mortar and shall be provided with positive means, such as discharge baffle or hopper, for preventing segregation of the concrete or loss of mortar at the transfer point(s) and the point of placing. The idler spacing shall not exceed 36 inches.Belt speed shall be a minimum of 750 feet per minute and a maximum of 1,000 feet per minute. Belts used to convey concrete from the batch plant to any point leading to the point of placement shall be designed for flowable concrete and stiffer concrete containing up to 4-inch aggregate. The belts shall be adequately sized per the manufacturer's recommendations, but shall not have a cross-sectional width less than 16 inches. The NMSA required in mixture proportions furnished by the Government will not be changed to accommodate the belt width. If concrete is to be placed through installed horizontal or sloping reinforcing bars, the conveyor shall discharge concrete into a pipe or elephant truck that is long enough to extend through the reinforcing bars.

3.1.4.3 Tremie Pipes

A funnel-shaped hopper of sufficient volume, but not less than 2 cubic yards, shall be required at the top of all tremie pipes. The hopper shall be of a size capable of receiving and passing the concrete into the pipe at the capacity rate of the batching, mixing and conveying equipment. The tremie pipe shall be as shown and/or specified elsewhere, or if not shown or specified, shall be of sufficiently large to permit the free flow of concrete. Tremie pipe shall be a minimum internal diameter of 10-inches for concrete made with 1 inch NMSA and 12 inches for concrete made with 1-1/2 inch NMSA. Tremie pipe shall be made of steel and have watertight joints. Hoisting equipment for lifting and lowering pipes and tools for connecting the pipe sections shall be continuously available and on hand.

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Each section of tremie pipe shall have threaded connections or shall have gasketed fittings. For pipe connections that are coupled and not threaded, the coupling alone will not be considered watertight. Additional external seals shall be provided around the coupling to assure a watertight connection. A plastic cap reinforced with a steel plate shall be secured to the bottom of pipes to prevent contact of the concrete or grout with water until the start of the placement. Before concrete is placed in the tremie pipe, the pipe with the cap and plate secured shall be lowered and put in contact with the bottom of the placement. After QC verification of a dry pipe, the pipe and hopper shall be fully charged, then the pipe shall be raised 6-inches to initiate flow of concrete. Additional concrete shall be ready at the point of placement to allow a continuous flow of concrete down the pipe.

3.2 TRANSPORTING CONCRETE AT PROJECT SITE

Concrete shall be transported to the placing site by approved conveyors.

The method used to transport concrete shall be adequate to achieve the concrete production capacity specified in paragraph Government-Furnished Concrete. Concrete for all placements, especially tremie and flowable concretes shall use a transport system that provides a continuous and uninterrupted flow of concrete.

3.3 CONVEYING CONCRETE ON SITE

Concrete shall be conveyed from the Points of Delivery to the point of placement as rapidly as possible and within the time interval specified by methods which will prevent segregation or loss of ingredients. Conveying equipment shall be cleaned before each placement. Methods and equipment for conveying and depositing the concrete into the form shall be subject to approval. The capacity of the transporting system shall be sufficient to supply concrete at a rate to prevent cold joints forming during placement.

The concrete shall not be dropped vertically more than 3 feet for tremie and flowable concrete and grout, and 5 feet for all other concrete, except where suitable equipment is provided to prevent segregation and where specifically authorized. A properly designed and sized elephant trunk and rigid drop chute bottom section which will prevent free-fall within the elephant trunk and rigid drop chute shall be used . If concrete is to be placed through installed horizontal or sloping reinforcing bars, the concrete shall discharge into a pipe or elephant trunk that is long enough to extend through the reinforcing bars to within 5 feet of the placing surface. In no case will concrete be discharged to free fall through the reinforcing bars. The Contractor is hereby alerted to project conditions and site restrictions that may affect concrete conveyance. Concrete conveyance shall not interfere with lock operation or navigation.

3.3.1 Transporting by Belt Conveyor

Methods and equipment for transporting the concrete by belt conveyor into the form shall be subject to approval. Sheet metal covers shall be provided over the conveyor and metal catch/drip pans shall be provided beneath the conveyor. The enclosures shall provide adequate protection from precipitation, sun and wind. Transfer points shall be provided with catch boxes that capture any spillage and wash water from cleaning the belts.

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