Attachment 4 Supplemental Specifications.pdf

PART 1 GENERAL

1.1 SCOPE

1.2 DEFINITIONS

1.2.1 Bracing

1.2.2 Delamination

SECTION TABLE OF CONTENTS

SECTION 030100

REHABILITATION OF CONCRETE

1.2.3 Rehabilitation

1.2.4 Repair

1.2.5 Shoring

1.2.6 Termination Joint

1.2.7 Unsound Concrete

1.3 ACCEPTANCE OF REHABILITATION WORK

1.3.1 General Requirements

1.3.2 Appearance

1.4 PROTECTION OF COMPLETED REHABILITATION WORK

PART 2 PRODUCTS

2.1 EQUIPMENT FOR CONCRETE PREPARATION

2.2 Surface preparation and cleaning equipment

2.2.1 Abrasive Blasting

2.2.2 Low Pressure Water Cleaning

2.2.3 Other Cleaning Equipment

2.3 CONVENTIONAL CONCRETE

2.4 POLYMERS

PART 3 EXECUTION

3.1 GENERAL REQUIREMENTS

3.1.1 Protection

3.1.2 Concrete Preparation

3.1.3 Quality Control

3.1.3.1 Quality control of surface preparation

3.1.4 Curing

3.1.5 Clean Up

3.1.6 Safety

3.2 CRACK REPAIR

3.2.1 Preparation

3.2.1.1 General Requirements

3.2.1.2 Crack routing

3.2.1.3 Sealing

3.2.2 Application

3.2.2.1 Epoxy injection

3.2.2.2 Gravity fill

3.2.2.3 Grout/Mortar

3.3 CORROSION AND SURFACE REPAIR

3.3.1 Preparation

3.3.1.1 Shoring and Formwork

3.3.1.2 Concrete Removal

3.3.1.3 Preparation of Concrete Substrate Surface

3.3.2 Application

3.3.2.1 Existing Reinforcement Preparation

3.3.2.2 Placement of New Reinforcement

3.3.2.3 Placement of Concrete

3.3.3 Quality Control

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PART 1 GENERAL

1.1 SCOPE

This specification governs the rehabilitation of structural and reinforced concrete.

1.2 DEFINITIONS

1.2.1 Bracing

Temporary supplemental members used to avoid local or global instability during construction, evaluation, or repair that are intended to be removed after completion of construction.

1.2.2 Delamination

A planar separation in a material that is roughly parallel to the surface of the material.

1.2.3 Rehabilitation

Repairing or modifying an existing structure to a desired useful condition.

1.2.4 Repair

The reconstruction or renewal of concrete parts of an existing structure for its maintenance or to correct deterioration, damage, or faulty construction of members or systems of a structure.

1.2.5 Shoring

Props or posts of timber or other material in compression used for the temporary support of excavations, formwork, or unsafe structures; the process of erecting shores.

1.2.6 Termination Joint

The interface where a placement of repair material meets existing concrete, the edge of an expansion joint, or other existing surfaces.

1.2.7 Unsound Concrete

Concrete that is fractured, delaminated, spalled, deteriorated, defective, contaminated or otherwise damaged.

1.3 ACCEPTANCE OF REHABILITATION WORK

1.3.1 General Requirements

a. Completed concrete rehabilitation work must conform to applicable requirements of Contract Document and this specification. The Contractor is responsible to bring Work into compliance with requirements of Contract Documents if the Concrete repair work fails to meet one or more requirements of Contract Documents.

b. Correct rejected repair work by removing and replacing or by strengthening with additional construction acceptable to the Contracting Officer. Use repair methods that meet applicable requirements for function, durability, dimensional tolerances, and appearance.

1.3.2 Appearance

Repairs when finished shall match existing finishes.

1.4 PROTECTION OF COMPLETED REHABILITATION WORK

a. Do not allow construction loads to exceed the loads that a structural member or structure is safely capable of supporting without damage.

Provide supplemental support if construction loads are expected to exceed safe load capacity.

b. Protect repaired and adjacent areas from damage by construction traffic, equipment, and materials. During the curing period, protect repair materials from damage by mechanical disturbances, including load-induced stresses, shock, and vibration.

c. Protect repair materials from environmental damage by weather events during the length of the curing period.

PART 2 PRODUCTS

Products or materials used must conform to the requirements of the Contract Documents. The usage of other products or materials not covered by the Contract Documents are permitted upon approval of the Government.

Additional information and submittals for products and materials not included in this document including product data, samples, manufacturer's instructions must be submitted as requested by the Contracting Officer.

2.1 EQUIPMENT FOR CONCRETE PREPARATION

Means and methods used for concrete removal and surface preparation must be selected and used such as to minimize damage to the structure and to the concrete substrate that remains.

2.2 Surface preparation and cleaning equipment

2.2.1 Abrasive Blasting

a. Use dry or wet oil-free abrasive blasting capable of removing loose micro-fractured (bruised) or otherwise damaged or pulverized concrete surfaces, and rust from exposed steel reinforcement, and providing a surface profile in compliance with the Contract Documents.

2.2.2 Low Pressure Water Cleaning

Use equipment capable of delivering sufficient pressure for cleaning loose material from repair areas.

2.2.3 Other Cleaning Equipment

Use equipment that delivers oil free air capable of cleaning loose material and debris from repair areas. If necessary to dry the concrete surface, gas-fired torches or clean, dry, compressed air may be used. Also, use vacuums capable of removing loose material and debris.

2.3 CONVENTIONAL CONCRETE

a. Portland cement concrete materials must meet requirements of Section

033000 CAST-IN-PLACE.

b. For cement based bonding systems use neat portland cement or a blend of portland cement and an ASTM C33/C33M fine aggregate filler proportioned one to one by mass. The water-to-cement ratio of the bonding mixture must be equal to the water-to-cement ratio of concrete used as a repair or overlay material. Water used must meet ASTM C1602/C1602M requirements.

2.4 POLYMERS

a. The requirements for the properties of polymers and aggregates used in polymers must meet the requirements specified in this paragraph.

b. Polymers used must be compatible with other polymers and materials used on the project. Unless repair materials are specified in the contract documents, the Contractor is responsible for verifying material compatibilities.

c. Submit product data, manufacturer's Safety Data Sheets, manufacturer's instructions, and field reports for materials as required by this document.

PART 3 EXECUTION

3.1 GENERAL REQUIREMENTS

3.1.1 Protection

Protect personnel, pedestrians, motorized traffic, mechanical, electrical, and plumbing equipment, surrounding construction, project site, landscaping, and surrounding buildings from damage or injury resulting from concrete rehabilitation work.

a. Construct dust and debris barriers surrounding repair work perimeter to control dust and to protect and control construction traffic.

b. Dispose of runoff from wet demolition or surface preparation operations in accordance with all local ordinances. Disposal methods must avoid soil erosion, avoid undermining pavements and foundations, damage to landscaping and vegetation, and minimize water penetration through other parts of buildings.

c. Collect and neutralize alkaline wastes and acid wastes and dispose in accordance with local, state, and federal regulations.

d. Comply with local noise ordinances during demolition operations.

e. Perform demolition work and surface preparation work in a manner that minimizes disturbances of operations. Coordinate work with the Contracting Officer.

f. Submit a proposed protection plan for approval by owner representative and Licensed Design Professional.

3.1.2 Concrete preparation

a. Remove concrete as needed per the removal requirements of this section.

Limits on removal equipment are specified in the paragraph titled

“EQUIPMENT FOR CONCRETE PREPARATION”.

b. Remove foreign material, such as dirt, oil, grease, or other chemicals, from the cracks before injection using compressed air, low-pressure water, or vacuuming. Allow wet surfaces to dry at least 24 hours.

3.1.3 Quality Control

3.1.3.1 Quality control of surface preparation

Evaluation of prepared substrate must be continuously monitored to assure that the prepared substrate surface meets project requirements.

3.1.4 Curing

a. For portland cement concrete work, follow the manufacturer’s requirements.

b. For polymer concrete/mortar Work, follow manufacturer's requirements for curing.

c. For polymer modified portland cement concrete work follow manufacturer's requirements for curing.

d. For Epoxy follow manufacturer's requirements for curing.

3.1.5 Clean up

a. Clean and remove all spills and leaks of injection adhesive and stains caused by the injection adhesives.

b. Dispose wastewater used for cutting and cleaning without staining or damaging the existing surfaces of the structure or the environment of the project area.

3.1.6 Safety

a. Provide Material Safety Data Sheets (MSDS) for products on site reviewing them before work begins.

b. Provide safety guards, maintenance, and warnings for all machinery and equipment.

c. Have personal protection equipment practice in place - eye protection and face guards.

d. Have all workers in contact with wet cementitious material wear protective gloves and clothing.

e. Provide eyewash facilities on-site with location signage.

f. Provide dust masks for workers operating mixers.

g. Have confined space procedures in place including adequate ventilation in closed spaces before operating equipment or using products that emit potentially dangerous or toxic exhaust, fumes, or dust.

h. Provide secured storage available for all hazardous or flammable materials.

3.2 CRACK REPAIR

3.2.1 Preparation

3.2.1.1 General Requirements

a. Clean all cracks in accordance with the paragraph titled Concrete Preparation.

b. Do not repair cracks when the temperature of the concrete is below freezing and moisture conditions indicate the possibility of ice on the internal surfaces of the crack.

c. Do not apply adhesive if the temperature of the concrete is not within the range of application temperatures recommended by the manufacturer of the adhesive.

3.2.1.2 Crack routing

Inspect surfaces adjacent to crack to receive repair material. If deteriorated, route a V-groove section at the crack face until sound concrete is reached.

3.2.1.3 Sealing

a. For epoxy injection, apply a surface seal over all exterior faces of the crack that can be reached to contain the injection adhesive in the crack.

b. For gravity fill repairs, apply a surface seal along the bottom surface of the element that can be reached to contain the repair material in the crack.

3.2.2 Application

3.2.2.1 Epoxy injection

a. Follow manufacturer’s instructions.

3.2.2.2 Gravity fill

a. Follow manufacturer's instructions.

3.2.2.3 Grout/Mortar

b. Mix per material manufacturer's instructions.

c. Pre-fill cracks at least 0.125 in. wide with aggregate.

d. Apply grout/mortar onto the surface, over the cracks and spread.

e. Work material back and forth over the cracks to maximize fill in crack.

f. Remove excess material once cracks have been filled to refusal.

g. Allow material to cure per material manufacturer's recommendations.

3.3 CORROSION AND SURFACE REPAIR

3.3.1 Preparation

3.3.1.1 Shoring and Formwork

a. Provide shoring and formwork as needed.

3.3.1.2 Concrete Removal

a. Remove concrete from repair areas to indicated depth and profile.

Notify Contracting Officer if additional delaminated, fractured, or unsound concrete is found.

b. Do not damage embedded reinforcing and adjacent concrete. The removal methods must produce minimal microcracking (bruising) of the prepared substrate surfaces. Avoid directly striking reinforcing steel with impact tools used for concrete removal.

c. Avoid cutting or damging embedded reinforcement or other embedded items. If embedded reinforcing steel or other embedded items are too close to the surface to avoid, contact the Contracting Officer for direction before proceeding.

d. Extend concrete removal along corroded reinforcing steel to a point where there is no further delamination, concrete cracking, or reinforcing steel corrosion, and where the reinforcement is bonded to the surrounding concrete.

e. Remove concrete around the exposed layer of reinforcement to a uniform depth beyond within the repair areas to provide a minimum clearance between exposed reinforcing steel and surrounding concrete of 0.75 in., or at least 0.25 in. larger than the maximum nominal size of the coarse aggregate in the repair material.

f. Do not remove concrete behind vertical reinforcing bars in columns.

3.3.1.3 Preparation of Concrete Substrate Surface

a. Visually inspect and sound substrate surface to confirm that no further delamination or otherwise unsound concrete remains. If encountered, notify the Contracting Officer.

b. Clean the substrate per the paragraph titled Concrete preparation.

3.3.2 Application

3.3.2.1 Existing Reinforcement Preparation

a. Clean existing reinforcement that will remain. Remove corrosion and/or other laitance and notify the Contracting Officer if section loss is greater than 20%.

b. Replace coating on reinforcement. Exposed areas must not exceed 2 percent of surface area in each linear foot of each bar.

3.3.2.2 Placement of New Reinforcement

Placement of new reinforcement

a. Placement of new reinforcement to replace or strengthen existing reinforcement is like new construction. Placement, splicing, and handling of new reinforcement must meet industry standard in common practices.

b. Reinforcement must be free of materials deleterious to bond. New reinforcement with rust, mill scale, or a combination of both will be considered satisfactory, provided minimum nominal dimensions, nominal weight, and minimum average height of deformations of a hand-wire-brushed test specimen are not less than applicable ASTM specification requirements.

3.3.2.3 Placement of Concrete

a. If portland cement concrete is used as the repair material, follow industry standards for proportioning, mixing, and placing concrete. For all other materials, follow material manufacturer's recommendations.

b. For vertical and overhead applications of portland cement concrete, use shotcrete.

e. Bristle broom a thin coat of the repair material into the saturated surface dry substrate filling roughened surface pores before placing the repair material in the repair area. Do not allow thin coat to dry before placing repair material.

g. Finish the surface to match surface finish and texture to match existing.

3.3.3 Quality Control

a. Protect concrete surfaces, beyond limits of surfaces receiving bonding agent adhesive, against spillage. Immediately remove any bonding agent adhesive that has spilled beyond desired area. Perform cleanup with material designated by bonding agent adhesive manufacturer. Avoid contamination of work area

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