Attachment J-2 G-Street Sidewalk Repair Spec.pdf

SELECTIVE STRUCTURE DEMOLITION

U.S. GOVERNMENT PUBLISHING OFFICE

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GALE JN 656429

G STREET NW - MAINTENANCE GARAGE

PROJECT IDENTIFICATION: U.S Government Publishing Office

G-Street Maintenance Garage

732 North Capitol Street

Washington, District of Columbia 20401

SECTION 024119 - SELECTIVE STRUCTURE DEMOLITION

PART 1 - GENERAL

1.1 SUMMARY

A. This Section specifies requirements for the following Scope of Work:

1. Removal of electrical conduits, and associated electrical wiring, as required.

2. Removal of chain link fencing, as indicated.

3. Removal of BMU and CMU walls, as required.

4. Removal of equipment, walls, fixtures, and fittings attached to slab, as required.

5. Remove miscellaneous equipment and furniture at basement level, as required.

6. Removal of existing concrete and stone stairs and ramps and brick masonry cheek walls.

7. Removal of metal guard rails and handrails.

8. Removal of existing sidewalk concrete wear course.

9. Removal of granite curb.

10. Removal of concrete, asphalt, granite, and brick street curb gutters.

11. Removal of existing waterproofing systems.

12. Removal of concrete sidewalk slab-on-grade and gravel course.

13. Removal of concrete apron slab-on-grade and gravel course.

14. Removal of sheet metal ductwork.

15. Removal of paint coatings.

16. Removal of lead-based paint coatings.

1.2 DEFINITIONS

A. Remove: Detach items from existing construction and legally dispose of them off-site, unless indicated to be removed and salvaged or removed and reinstalled.

B. Remove and Salvage: Detach items from existing construction and deliver them to Owner ready for reuse.

C. Remove and Reinstall: Detach items from existing construction, prepare them for reuse, and reinstall them where indicated.

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D. Existing to Remain: Existing items of construction that are not to be removed and that are not otherwise indicated to be removed, removed and salvaged, or removed and reinstalled.

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1.3 SUBMITTALS

A. Schedule of Selective Demolition Activities: Indicate detailed sequence of selective demolition and removal work, with starting and ending dates for each activity, interruption of utility services, and locations of temporary set up areas.

B. Predemolition Photographs or Videotapes: Show existing conditions of adjoining construction and site improvements, including finish surfaces, that might be misconstrued as damage caused by selective demolition operations. Submit before Work begins.

C. Landfill Records: Indicate receipt and acceptance of hazardous wastes by a landfill facility licensed to accept hazardous wastes.

D. Proposed locations of dumpsters, hoists, and other temporary equipment or facilities required for demolition work.

E. Proposed methods for interior and exterior protection and clean-up during removal operations.

F. Provide schedule, updated weekly, indicating areas of sidewalk where demolition will occur.

Notify Owner of schedule changes.

1.4 QUALITY ASSURANCE

A. Demolition Firm Qualifications: An experienced firm that has specialized in demolition work similar in material and extent to that indicated for this Project.

B. Regulatory Requirements: Comply with governing EPA notification regulations before beginning selective demolition. Comply with hauling and disposal regulations of authorities having jurisdiction.

C. Standards: Comply with ANSI A10.6 and NFPA 241; OSHA, 29 CFR 1926.1101; EPA, NESHAP 40 CFR, Part 60.

D. Comply with Federal, State and Local requirements.

1.5 PROJECT CONDITIONS

A. Owner will occupy portions of building immediately below and adjacent to selective demolition area. Conduct selective demolition so Owner's operations and utilities will not be disrupted.

B. Notify Architect of discrepancies between existing conditions and Drawings before proceeding with selective demolition.

C. Hazardous Materials: It is not expected that hazardous materials will be encountered in the Work.

1. Do not disturb hazardous materials except as directed under the hazardous materials abatement plan. The plan shall be prepared, signed, and sealed by a certified industrial hygienist. The remediation plan shall conform to the following minimum criteria:

a. Provide a detailed job-specific plan of the work procedures to be used in the disturbance of hazardous materials. The plan shall include location and extent of the

024119 - 4 removal area, critical barriers, physical boundaries, location and details of decontamination facilities, viewing ports, and mechanical ventilation systems.

Include a description of the personal protective equipment required, specific work practices, controls and job responsibilities for individuals. Include in the plan, interface of trades, sequencing of related work, collected debris, air sampling and a detailed description of the method of containment of the operation to ensure that hazardous materials are not released outside of the control areas. Include site preparation, cleanup and clearance procedures. Include occupational and environmental sampling, training and strategy, sampling and analysis strategy and methodology, frequency of sampling, duration of sampling, and qualifications of sampling personnel in the air sampling portion of the plan. Include a description of arrangements made among contractors on multi-contractor worksites to inform affected employees and to clarify responsibilities to control exposures. The plan shall also include an occupant protection program that describes the measures that will be taken during the work to notify and protect the building occupants.

2. All workers shall have training certifications in the removal or supervision of the removal of the hazardous materials in question.

D. Storage or sale of removed items or materials on-site is not permitted.

E. Utility Service: Maintain existing utilities to remain in service and protect them against damage during selective demolition operations.

1. Maintain fire-protection facilities in service during selective demolition operations.

1.6 DEMOLITION AND TRANSPORT

A. Conveyances: Buggies, wheelbarrows, or other equipment or machinery used to transport removed debris to dumpsters, shall be of size and design to prevent damage to existing pavements, sidewalks, other adjacent construction and occupant vehicles that may be present in parking areas.

B. Mechanical cutting equipment: Cutting equipment shall be equipped with operable blade depth setting mechanisms to control cutting depth of blade and prevent damage to structural steel reinforcement and structural steel beams during cutting operations.

C. Use of “bobcat” type removal equipment on the structural slab is prohibited.

PART 2 - PRODUCTS (Not Used)

PART 3 - EXECUTION

3.1 EXAMINATION

A. Survey existing conditions and correlate with requirements indicated to determine extent of selective demolition required.

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B. Locate utilities embedded in structural slabs and walls affected by the work. Utilities shall be protected during the work. Utilities damaged by the Contractor will be repaired at no cost to

Owner.

C. When unanticipated mechanical, electrical, or structural elements that conflict with intended function or design are encountered, investigate and measure the nature and extent of conflict.

Promptly submit a written report to Owner.

3.2 GENERAL

A. During removal of existing materials, report to GPO areas of damaged, deteriorated, or otherwise unsuitable structural slab exposed during work. Do not cover or remove unacceptable structural slab until reviewed by GPO. Provide temporary protection and shoring at areas in question.

B. Take precautions to prevent water from migrating into building.

C. Set cutting blades of mechanical cutting equipment to proper depth to prevent scoring or damage to structural steel reinforcement, structural steel beams and embedded utilities.

D. Control visible emissions during concrete removal and at dumpster.

3.3 SELECTIVE DEMOLITION

A. Demolish and remove existing materials as expressly indicated or implied on the drawings.

Demolition shall include but may not be limited to the following:

1. Remove existing sidewalk concrete wear course, sidewalk waterproofing system, sidewalk concrete and stone stairs and ramps and associated metal guardrails and handrails and brick masonry cheek walls, sidewalk granite curbs, concrete and brick street gutters, sidewalk slab-on-grade, apron slab-on-grade, and associated components in preparation for new systems.

B. Removed and Reinstalled Items:

1. Clean and repair items to functional condition adequate for intended reuse. Paint to match.

2. Pack or crate items after cleaning and repairing. Identify contents of containers.

3. Protect items from damage during transport and storage.

4. Reinstall items in locations indicated. Comply with installation requirements for new materials and equipment. Provide connections, supports, and miscellaneous materials necessary to make item functional for use indicated.

C. Existing Items to Remain: Protect construction including embedded utilities indicated to remain against damage and soiling during selective demolition. When permitted by Owner, items may be removed to a suitable, protected storage location during selective demolition and cleaned and reinstalled in their original locations after selective demolition operations are complete.

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3.4 DISPOSAL OF DEMOLISHED MATERIALS

A. General: Except for items or materials indicated to be recycled, reused, salvaged, reinstalled, or otherwise indicated to remain Owner's property, remove demolished materials from Project site and legally dispose of them in an EPA-approved landfill.

B. Burning: Do not burn demolished materials.

C. Disposal: Transport demolished materials off Owner's property and legally dispose of them.

3.5 CLEANING

A. Clean demolition materials and debris daily.

B. Clean all surfaces of suspended lighting and accessories within the basement, and similar areas with exposed framing.

C. Repair damage to building by replacing damaged material or component in-kind.

D. Clean site daily to satisfaction of Owner.

E. Dispose of debris and demolition materials at landfill in accordance with applicable regulations.

END OF SECTION 024119

CAST-IN-PLACE CONCRETE

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SECTION 033000 - CAST-IN-PLACE CONCRETE

1.1 SUMMARY

A. Section includes cast-in-place concrete, including formwork, reinforcement, concrete materials, mixture design, placement procedures, and finishes.

1.2 RELATED DOCUMENTS

A. Drawings and general provisions of the Contract, including General and Supplementary

Conditions and Division 01 Specification Sections.

B. Section 037000 Concrete Repairs.

1.3 PREINSTALLATION CONFERENCE

A. A preconstruction conference will be held with the Owner, Contractor, Engineer, and involved trades to discuss aspects of cast-in-place concrete construction. The Contractor's foreman or field representative will attend this conference. The foreman must be proficient in reading and writing English and shall be on site at all times that work is performed.

B. The Owner shall reserve the right to require an alternate superintendent and/or foreman.

C. The preconstruction conference shall not be held until all specified submittals have been received, reviewed, and accepted as to form by the Owner and Owner’s Representative.

D. Delivery of materials and commencement of construction shall not proceed until the preconstruction conference is held. Delays in obtaining a complete set of submittals shall not extend the contracted completion date.

1.4 ACTION SUBMITTALS

A. Product Data: For each type of product.

B. Design Mixtures: For each concrete mixture.

C. Steel Reinforcement Shop Drawings: Placing Drawings that detail fabrication, bending, and placement.

D. Form Work Shop Drawings: Prepared by or under the supervision of a qualified professional engineer, detailing fabrication, assembly, and support formwork.

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1.5 INFORMATIONAL SUBMITTALS

A. Material Certificates:

1. Steel reinforcement and accessories.

2. Curing compounds.

3. Floor and slab treatments.

4. Bonding agents.

5. Adhesives.

6. Repair materials.

B. Material Test Reports

1.6 QUALITY ASSURANCE

A. Installer Qualifications: A qualified installer who employs Project personnel qualified as ACI-certified Flatwork Technician and Finisher and a supervisor who is an ACI-certified Concrete

Flatwork Technician.

B. Manufacturer Qualifications: A firm experienced in manufacturing ready-mixed concrete products and that complies with ASTM C 94/C 94M requirements for production facilities and equipment.

1. Manufacturer certified according to NRMCA's "Certification of Ready Mixed Concrete

Production Facilities."

C. Testing Agency Qualifications: An independent agency, qualified according to ASTM C 1077 and ASTM E 329 for testing indicated.

1.7 PRECONSTRUCTION TESTING

A. Preconstruction Testing Service: Engage a qualified testing agency to perform preconstruction testing on concrete mixtures.

1.8 DELIVERY, STORAGE, AND HANDLING

A. Steel Reinforcement: Deliver, store, and handle steel reinforcement to prevent bending and damage. Avoid damaging galvanizing on steel reinforcement.

1.9 FIELD CONDITIONS

A. Cold-Weather Placement: Comply with ACI 306.1 and as follows. Protect concrete work from physical damage or reduced strength that could be caused by frost, freezing actions, or low temperatures.

1. Do not use calcium chloride, salt, or other materials containing antifreeze agents or chemical accelerators unless otherwise specified and approved in mixture designs.

B. Hot-Weather Placement: Comply with ACI 301.

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PART 2 - PRODUCTS

2.1 CONCRETE, GENERAL

A. ACI Publications: Comply with the following unless modified by requirements in the Contract

Documents:

1. ACI 301.

2. ACI 117.

2.2

FORM-FACING MATERIALS

A. Rough-Formed Finished Concrete: Plywood, lumber, cork, or another approved material.

2.3

STEEL REINFORCEMENT

A. Galvanized Reinforcing Bars: ASTM A 615/A 615M, Grade 60 deformed bars. Various sizes to match existing at top and bottom mats.

B. Galvanized-Steel Welded-Wire Reinforcement: ASTM A 1064/A 1064M, plain, fabricated from galvanized-steel wire into flat sheets. Various sizes.

2.4

REINFORCEMENT ACCESSORIES

A. Bar Supports: Bolsters, chairs, spacers, and other devices for spacing, supporting, and fastening reinforcing bars and welded-wire reinforcement in place. Manufacture bar supports from steel wire, plastic, or precast concrete according to CRSI's "Manual of Standard Practice," of greater compressive strength than concrete.

2.5

CONCRETE MATERIALS

A. Source Limitations: Obtain each type or class of cementitious material of the same brand from the same manufacturer's plant, obtain aggregate from single source, and obtain admixtures from single source from single manufacturer.

B. Cementitious Materials:

1. Portland Cement: ASTM C 150/C 150M, Type II white.

2. Fly Ash: ASTM C 618, Class F or C.

3. Slag Cement: ASTM C 989/C 989M, Grade 100 or 120.

C. Normal-Weight Aggregates: ASTM C 33/C 33M, graded.

1. Maximum Coarse-Aggregate Size: 1 inch nominal.

2. Fine Aggregate: Free of materials with deleterious reactivity to alkali in cement.

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D. Air-Entraining Admixture: ASTM C 260/C 260M.

E. Chemical Admixtures: Certified by manufacturer to be compatible with other admixtures and that do not contribute water-soluble chloride ions exceeding those permitted in hardened concrete. Do not use calcium chloride or admixtures containing calcium chloride.

1. Water-Reducing Admixture: ASTM C 494/C 494M, Type A.

2. Retarding Admixture: ASTM C 494/C 494M, Type B.

3. Water-Reducing and Retarding Admixture: ASTM C 494/C 494M, Type D.

4. High-Range, Water-Reducing Admixture: ASTM C 494/C 494M, Type F.

5. High-Range, Water-Reducing and Retarding Admixture: ASTM C 494/C 494M, Type G.

6. Plasticizing and Retarding Admixture: ASTM C 1017/C 1017M, Type II.

F. Water: ASTM C 94/C 94M and potable

2.6 CURING MATERIALS

A. Moisture-Retaining Cover: ASTM C 171, polyethylene film or white burlap-polyethylene sheet.

B. Water: Potable.

2.7 RELATED MATERIALS

A. Bonding Agent: ASTM C 1059/C 1059M, Type II, nonredispersible, acrylic emulsion or styrene butadiene.

B. Bar supports: Bolsters, chairs, spacers, and other devices for spacing, supporting, and fastening reinforcing bars. Manufacture bar supports according to CRSI’s “Manual of Standard Practice” from steel wire or plastic. Tips of chair or bolster supports shall be plastic capped, or hot-dip galvanized.

C. Epoxy for setting dowel reinforcement into existing concrete sections: Sikadur 32, Hi-Mod by

Sika Corp. or Sikadur 33 structural paste adhesive by Sika Corp. or approved equal.

2.8 CONCRETE MIXTURES, GENERAL

A. Prepare design mixtures for each type and strength of concrete, proportioned on the basis of laboratory trial mixture or field test data, or both, according to ACI 301.

B. Cementitious Materials: Use fly ash, pozzolan, slag cement, and silica fume as needed to reduce the total amount of portland cement, which would otherwise be used, by not less than 40 percent.

C. Admixtures: Use admixtures according to manufacturer's written instructions.

1. Use water-reducing high-range water-reducing or plasticizing admixture in concrete, as required, for placement and workability.

2. Use water-reducing and -retarding admixture when required by high temperatures, low humidity, or other adverse placement conditions.

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2.9 CONCRETE MIXTURES

A. Normal-weight concrete.

1. Minimum Compressive Strength: 4000 psi at 28 days.

2. Maximum W/C Ratio: 0.40.

3. Slump Limit: 2 - 5 inches max.

4. Air Content: 6 percent, plus or minus 1.5 percent at point of delivery for 1-inch nominal maximum aggregate size.

2.10 FABRICATING REINFORCEMENT

A. Fabricate steel reinforcement according to CRSI's "Manual of Standard Practice."

2.11 CONCRETE MIXING

A. Ready-Mixed Concrete: Measure, batch, mix, and deliver concrete according to

ASTM C 94/C 94M, and furnish batch ticket information.

1. When air temperature is between 85 and 90 deg F, reduce mixing and delivery time from

1-1/2 hours to 75 minutes; when air temperature is above 90 deg F, reduce mixing and delivery time to 60 minutes.

3.1 GENERAL

A. Remove all equipment, fixtures, and fittings at areas to receive concrete repairs, as indicated on the drawings and as required.

B. Verify location and extent of spalled, delaminated, cracked, and otherwise deteriorated concrete shown on the Drawings. Any discrepancies with the drawings shall be brought to the attention of the Owner.

C. Identify perimeter of deteriorated areas of concrete scheduled to be removed/repaired with spray paint.

D. Provide all devices (including heaters and ventilation) necessary to maintain areas at the proper temperature and humidity for the curing of repair mortar, concrete, epoxy, and sealant materials.

E. No concrete repair work shall be executed when the temperature in the work areas has dropped below 45 degrees Fahrenheit, unless heated. Consult the manufacturers of the materials for proper application and storage procedures.

F. Remove all areas of deteriorated, delaminating, debonded, spalled or otherwise damaged concrete. Do not cut existing reinforcing steel bars.

G. Apply coating/bonding agent to adjoining substrate surfaces and existing reinforcing steel as recommended by the repair materials manufacturer. Slurry scrub profiling mortar into prepared damp substrates

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3.2 REINFORCING STEEL AT CONCRETE REPAIR

A. At reinforcing bars, perform the following work:

1. Reinforcing steel must be mechanically cleaned and free of rust, scale, grease, oil and other bond-inhibiting matter in accordance with SSPC – SP11, at a minimum and as required by the rebar bonding agent manufacturer. This can be accomplished using hand-held wire brush, power tools or similar approved methods.

2. After cleaning of reinforcement to bare metal, thoroughly examine and determine section loss. Bars with 15% or greater section loss shall receive supplemental galvanized steel.

New steel bars shall be placed and tied along side of existing corroded bar at same depth where possible. Bar lap shall be developed 20 bar diameters, each end, beyond point of corroded bar. Remove additional concrete as required to fit bar and develop lap lengths.

New bar diameter shall match existing nominal bar diameter prior to corrosion or as directed by engineer. In all cases, new reinforcement shall have a minimum concrete or mortar cover of 1-1/2 inches.

3. At discontinuous ends of reinforcement or where 20 bar diameter lap is not possible, supplemental reinforcement may be drilled and epoxied into the substrate adjacent to existing corroded bars. Drill hole 1/4” diameter larger than bar diameter at a depth 10 times the bar diameter. Maintain a minimum 2-inch cover and edge distance at all drilled hole locations. Clean hole and fill with a high modulus, high strength, structural epoxy paste adhesive conforming to ASTM C-881 and AASHTO M-235 specifications.

4. Apply bonding agent to all exposed steel surfaces using brushes in strict accordance with the bonding agent manufacturer’s written requirements.

5. Apply concrete as specified and recommended by the manufacturer. Allow to partially cure and finish to match the surrounding surface.

6. Clean areas adjacent to the repair area prior to curing with a moist sponge or cloth immediately after application.

7. Apply all curing materials and techniques as specified in this section.

3.3 FORMWORK INSTALLATION

A. Design, erect, shore, brace, and maintain formwork, according to ACI 301, to support vertical, lateral, static, and dynamic loads, and construction loads that might be applied, until structure can support such loads.

B. Construct formwork so concrete members and structures are of size, shape, alignment, elevation, and position indicated, within tolerance limits of ACI 117.

C. Chamfer exterior corners and edges of permanently exposed concrete.

3.4 INSTALLATION OF GALVANIC ANODES

A. Anodes shall be installed inside each repair area adjacent to the repair edges.

B. Space anodes 18-inches on center typically, or a maximum spacing of 24-inches on center.

C. Anodes shall be securely tied to prepared reinforcing steel.

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D. Maintain a minimum mortar cover of 1/2-inch or concrete cover of 1 inch over all anode surfaces.

E. Anodes with damaged cementitious shells will not be used.

F. Do not apply bonding agent to surfaces of anodes. Such anodes will be immediately rejected and replaced at no additional cost.

G. Contractor must contact the manufacturer prior to application of anodes to secure manufacturer field visits for all initial stages of anode installation. A minimum of 5 (five) anode installations shall be observed by the manufacturer. Manufacturer shall submit written report for each field visit to the Owner.

3.5 EMBEDDED ITEM INSTALLATION

A. Place and secure anchorage devices and other embedded items required for adjoining work that is attached to or supported by cast-in-place concrete. Use setting drawings, templates, diagrams, instructions, and directions furnished with items to be embedded.

3.6 REMOVING AND REUSING FORMS

A. General: Formwork for sides of beams, walls, columns, and similar parts of the Work that does not support weight of concrete may be removed after cumulatively curing at not less than 50 deg F for 24 hours after placing concrete. Concrete has to be hard enough to not be damaged by form-removal operations and curing and protection operations need to be maintained.

1. Leave formwork for beam soffits, joists, slabs, and other structural elements that support weight of concrete in place until concrete has achieved its 28-day design compressive strength.

2. Remove forms only if shores have been arranged to permit removal of forms without loosening or disturbing shores.

B. Clean and repair surfaces of forms to be reused in the Work. Split, frayed, delaminated, or otherwise damaged form-facing material are not acceptable for exposed surfaces. Apply new form-release agent.

C. When forms are reused, clean surfaces, remove fins and laitance, and tighten to close joints.

Align and secure joints to avoid offsets. Do not use patched forms for exposed concrete surfaces unless approved by Architect.

3.7 STEEL REINFORCEMENT INSTALLATION

A. General: Comply with CRSI's "Manual of Standard Practice" for fabricating, placing, and supporting reinforcement.

3.8 CONCRETE PLACEMENT

A. Before placing concrete, verify that installation of formwork, reinforcement, and embedded items is complete and that required inspections are completed.

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B. Deposit concrete continuously in one layer or in horizontal layers of such thickness that no new concrete is placed on concrete that has hardened enough to cause seams or planes of weakness.

If a section cannot be placed continuously, provide construction joints as indicated. Deposit concrete to avoid segregation.

1. Consolidate placed concrete with mechanical vibrating equipment according to ACI 301.

3.9 FINISHING FORMED SURFACES

A. Rough-Formed Finish: As-cast concrete texture imparted by form-facing material with tie holes and defects repaired and patched. Remove fins and other projections that exceed specified limits on formed-surface irregularities.

3.10 FINISHING

A. General: Comply with ACI 302.1R recommendations for screeding, restraightening, and finishing operations for concrete surfaces. Do not wet concrete surfaces.

3.11 CONCRETE PROTECTING AND CURING

A. General: Protect freshly placed concrete from premature drying and excessive cold or hot temperatures. Comply with ACI 306.1 for cold-weather protection and ACI 301 for hot-weather protection during curing.

B. Formed Surfaces: Cure formed concrete surfaces, including underside of beams, supported slabs, and other similar surfaces. If forms remain during curing period, moist cure after loosening forms. If removing forms before end of curing period, continue curing for remainder of curing period.

C. Cure concrete according to ACI 308.1, by one or a combination of the following methods:

1. Moisture Curing: Keep surfaces continuously moist for not less than seven days.

2. Moisture-Retaining-Cover Curing: Cover concrete surfaces with moisture-retaining cover for curing concrete, placed in widest practicable width, with sides and ends lapped at least 12 inches, and sealed by waterproof tape or adhesive. Cure for not less than seven days. Immediately repair any holes or tears during curing period, using cover material and waterproof tape.

3. Curing Compound: Apply uniformly in continuous operation by power spray or roller according to manufacturer's written instructions. Recoat areas subjected to heavy rainfall within three hours after initial application. Maintain continuity of coating and repair damage during curing period.

a. Removal: After curing period has elapsed, remove curing compound without damaging concrete surfaces by method recommended by curing compound manufacturer.

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3.12 CONCRETE SURFACE REPAIRS

A. Defective Concrete: Repair and patch defective areas when approved by Engineer. Remove and replace concrete that cannot be repaired and patched to Engineer's approval.

B. Repair materials and installation not specified above may be used, subject to Engineer's approval.

3.13 FIELD QUALITY CONTROL

A. Special Inspections: Contractor will engage a special inspector and qualified testing and inspecting agency to perform field tests and inspections and prepare test reports.

B. Testing Agency: Engage a qualified testing and inspecting agency to perform tests and inspections and to submit reports.

C. Inspections:

1. Steel reinforcement placement.

2. Steel reinforcement welding.

3. Headed bolts and studs.

4. Verification of use of required design mixture.

5. Concrete placement, including conveying and depositing.

6. Curing procedures and maintenance of curing temperature.

7. Verification of concrete strength before removal of shores and forms from beams and slabs.

D. Concrete Tests: Testing of composite samples of fresh concrete obtained according to

ASTM C 172/C 172M shall be performed according to the following requirements:

1. Testing Frequency: Obtain one composite sample for each day's pour of each concrete mixture exceeding 5 cu. yd., but less than 25 cu. yd., plus one set for each additional 50

cu. yd. or fraction thereof.

a. When frequency of testing provides fewer than five compressive-strength tests for each concrete mixture, testing shall be conducted from at least five randomly selected batches or from each batch if fewer than five are used.

2. Slump: ASTM C 143: one test at point of placement for each composite sample, but not less than one test for each day's pour of each concrete mixture. Perform additional tests when concrete consistency appears to change.

3. Air Content: ASTM C 231, pressure method, for normal-weight concrete; one test for each composite sample, but not less than one test for each day's pour of each concrete mixture.

4. Concrete Temperature: ASTM C 1064; one test hourly when air temperature is 40 deg F and below or 80 deg F and above, and one test for each composite sample.

5. Compression Test Specimens: ASTM C 31.

a. Cast and laboratory cure two sets of two standard cylinder specimens for each composite sample.

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b. Cast and field cure two sets of two standard cylinder specimens for each composite sample.

6. Compressive-Strength Tests: ASTM C 39; test one set of two laboratory-cured specimens at 7 days and one set of two specimens at 28 days.

a. Test one set of two field-cured specimens at 7 days and one set of two specimens at 28 days.

b. A compressive-strength test shall be the average compressive strength from a set of two specimens obtained from same composite sample and tested at age indicated.

7. When strength of field-cured cylinders is less than 85 percent of companion laboratory-cured cylinders, Contractor shall evaluate operations and provide corrective procedures for protecting and curing in-place concrete.

8. Strength of each concrete mixture will be satisfactory if every average of any three consecutive compressive-strength tests equals or exceeds specified compressive strength and no compressive-strength test value falls below specified compressive strength by more than 500 psi.

9. Test results shall be reported in writing to Engineer, concrete manufacturer, and

Contractor within 48 hours of testing. Reports of compressive-strength tests shall contain

Project identification name and number, date of concrete placement, name of concrete testing and inspecting agency, location of concrete batch in Work, design compressive strength at 28 days, concrete mixture proportions and materials, compressive breaking strength, and type of break for both 7- and 28-day tests.

10. Nondestructive Testing: Impact hammer, sonoscope, or other nondestructive device may be permitted by Engineer but will not be used as sole basis for approval or rejection of concrete.

11. Additional Tests: Testing and inspecting agency shall make additional tests of concrete when test results indicate that slump, air entrainment, compressive strengths, or other requirements have not been met, as directed by Engineer. Testing and inspecting agency may conduct tests to determine adequacy of concrete by cored cylinders complying with

ASTM C 42 or by other methods as directed by Engineer.

12. Additional testing and inspecting, at Contractor's expense, will be performed to determine compliance of replaced or additional work with specified requirements.

13. Correct deficiencies in the Work that test reports and inspections indicate do not comply with the Contract Documents.

E. Measure floor and slab flatness and levelness according to ASTM E 1155 within 24 hours of finishing.

END OF SECTION 033000

CONCRETE REPAIRS

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SECTION 037000 – CONCRETE REPAIRS

PART 1 – GENERAL

1.01 SUMMARY

A. This section specifies requirements for the following Scope of Work:

1. Prepare and repair cracked, spalled, delaminated and otherwise deteriorated structural concrete slabs, and concrete encased structural steel framing at locations indicated on the drawings and as encountered during the work.

2. Provide the following:

a. Concrete spall repairs at structural concrete slabs including horizontal and overhead repairs.

b. Form and pour repairs at full-depth concrete section deterioration.

c. Concrete spall repairs at concrete encasement of structural steel framing including vertical and overhead repairs.

d. Install cathodic protection at structural slab concrete repairs.

e. Pressure injected epoxy repairs at cracks in structural slabs.

f. Steel reinforcement cleaning and splicing.

g. Pinning, doweling, and mesh reinforcing at concrete repairs.

h. Supplemental steel reinforcement at concrete repairs.

1.02 RELATED DOCUMENTS

Conditions and Division 01 and 03 Specification Sections, apply to this Section.

B. Section 033000 Cast-in-place concrete.

1.03 JOB CONDITIONS

A. Coordinate the work in this Section with the work by other trades to ensure the orderly progress of the work.

B. The General Contractor shall utilize skilled and experienced specialty workers to install the work. Experienced trade workers shall be utilized for all aspects of the work.

C. Materials which are at a temperature other than the recommended application temperatures of the manufacturer or applicable standard shall not be applied.

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1.04 TEST AREAS

A. Before full scale work is commenced, execute the following work for trial work areas to be reviewed by the Manufacturer’s Field Representative Engineer as to surface preparation and material application acceptability and to ensure that color, texture and appearance match the existing construction.

1. 1 overhead concrete spall repair at a beam (minimum 10 s.f. each) including doweling, pinning, and reinforcement replacement.

2. 1 complete epoxy injection repair operation (minimum 10 l.f.)

B. Repairs shall conform to the contract documents and manufacturer’s instructions and once accepted shall become a standard for all subsequent work.

C. Trial areas shall be repeated until acceptable results are obtained and the accepted areas shall be a standard for all subsequent work. Construction of test areas shall be in conformance with all contract documents and shall use only submitted materials. After curing for seven days, the test areas shall be viewed, sampled and/or removed as directed by the Engineer to establish to his satisfaction the actual performance of the installed materials. Evidence of improper or unsatisfactory performance shall be grounds for rejection of any or all of the submitted materials.

1.05 REFERENCES

A. “Standard Specifications for Structural Concrete” (ACI 301) by American Concrete

Institute, herein referred to as ACI 301, is included in total as specification for this structure except where more stringent requirements are shown of Drawings or specified herein.

B. Comply with provisions of following codes, specifications and standards except where more stringent requirements are shown on Drawings or specified herein:

1. “Building Code Requirements for Reinforced Concrete” (ACI 318). American

Concrete Institute herein referred to as ACI 318.

2. “Causes, Evaluation, and Repair of Cracks in Concrete Structures” (ACI 224, 112), American Concrete Institute.

3. “State-of-the-Art Report on Parking Structures” (ACI 326), American Concrete

Institute.

4. “Use of Epoxy Compounds with Concrete” (ACI 503)

5. “Hot Weather Concreting” reported by ACI Committee 305 (ACI 305R-91).

6. “Cold Weather Concreting” reported by ACI Committee 306 (ACI 306R-

88).

C. Contractor shall have following ACI publication at Project construction site at all times:

1. “Use of Epoxy Compounds with Concrete” (ACI 503), American Concrete

Institute.

2. “Hot Weather Concreting” reported by ACI Committee 305 (ACI 305R).

3. “Cold Weather Concreting” reported by ACI Committee 306 (ACI 306R).

Commented [WG1]: Confirm we are including crack repair for structural slab

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D. American Society for Testing and Materials (ASTM):

1. ASTM C109, “Test Method for Compressive Strength of Hydraulic Cement

Mortars (Using 2-in. or 50-mm Cube Specimens).”

1.07 SUBMITTALS

A. Submit all repair mortar, sealant, and epoxy product technical data sheets to Engineer for approval of use.

B. Submit manufacturers’ field representative’s inspection report for each visit, indicating surface preparation and material application with curing, and any other pertinent data.

C. Submit associated equipment and materials list, including, but not limited to surface preparation equipment and methods used, pinning and mesh hardware, injection apparatus, sealants, primers, bonding agents, etc.

1.08 QUALITY ASSURANCE

A. Contractor must coordinate with appropriate manufacturer’s field representative to review surface preparations, application procedures, and curing operations. Refer to part

1.04 “Test Areas”.

B. Any surface preparation or material application type which has not been representatively witnessed by the manufacturer prior to initiating that type of repair shall be immediately rejected without exception. Repair will be completely redone at the Contractor’s expense.

PART 2 – MATERIALS

2.01 CONCRETE SPALL REPAIR MATERIALS

A. Hand applied patching mortar for vertical or overhead concrete spalls shall be a polymer modified non-sag cementitious repair mortar such as:

1. Sika Top 123 Plus; Sika Corporation.

2. Emaco R350 CI; Master Builders, ChemRex.

3. King SuperTop; KPM Company.

B. Patching mortar or concrete for horizontal concrete spalls shall be a polymer modified cementitious repair mortar, such as:

1. Sika Top 122; Sika Corporation.

2. Emaco R310 CI; Master Builders, ChemRex.

3. King LM-56; KPM Company.

C. Form and pour patching mortar for concrete spalls shall be a cementitious repair mortar, such as:

1. Sika Mono Top 611; Sika Corporation.

2. Emaco R310 CI; Master Builders, ChemRex.

3. King MS-56 SCC: KPM Company.

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D. Reinforcing bar coating/bonding agent shall be an epoxy modified, cementitious material designed specifically for use as both reinforcing bar protection and as a bonding agent such as:

1. Sika Armatec 110 EpoCem as manufactured by the Sika Corporation.

2. Emaco P24 as manufactured by the Master Builders, ChemRex, Inc.

2.02 EPOXY CRACK INJECTION AND GRAVITY-FEED MATERIALS

A. Passive or structural cracks through slabs shall be pressure injected with epoxy repair, utilizing the following materials:

1. Full depth cracks less than 1/16” width: Super low viscosity, moisture-tolerant epoxy injection adhesive such as Sikadur 55 or approved equal conforming to

ASTM C-881 and AASHTO M-235. Viscosity alternates to be based upon required depth of travel and port spacing as determined in field to obtain full substrate adhesion, as approved by the Engineer.

2. Cracks 1/16” to 1/4” in width: High modulus, low viscosity, high strength epoxy adhesive such as Sikadur 35, Hi-Mod LV, or approved equal conforming to

ASTM C-881 and AASHTO M-235. Viscosity alternates to be based upon required depth of travel and port spacing as determined in field to obtain full substrate adhesion, as approved by the Engineer.

3. Cracks greater than 1/4” to 3/8” width (injection only): High modulus high strength epoxy adhesive extended with epoxy mortar sand such as Sikadur 32, Hi-mod or Sikadur 31, Hi-Mod Gel by Sikacorp or approved equal conforming to

ASTM C-881 and AASHTO M-235. Viscosity alternates to be based upon required depth of travel and port spacing as determined in field to obtain full substrate adhesion, as approved by the Engineer.

4. Epoxy Mortar Sand for extending epoxy: Clean, well graded passing 20-40 mesh with no fines and no moisture. Required to extend all epoxies when used in glue line widths exceeding their tolerable recommended values. Refer to manufacturer literature for maximum glue-line widths.

5. Cap Seal and Port Binder: High modulus, high strength structural, very rapid curing smooth paste adhesive such as Sikadur 33 by Sika Corp. or approved equal.

2.03 EMBEDDED GALVANIC ANODES

A. Embedded galvanic anodes to be tied to reinforcing steel or placed within substrate of all repairs shall be:

1. Corr-Stops CI: Master Builders; BASF Construction Chemicals

2. Sentinel-GL; The Euclid Company.

3. Ferro Gard 670; Sika Corporation

2.05 ACCESSORY MATERIALS

A. Fasteners for concrete spalls that exceed 1-1/2” in depth shall be minimum 1-1/2” long by

1/4” diameter drive pins in stainless steel sheaths as manufactured by Star, Rawl, or equal. Embedment into substrate shall be 1-1/4” minimum. It is recommended that stainless steel pins have through-holes at exposed ends to accept tie wire.

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B. Type 304 stainless steel or hot dip galvanized wire mesh to be wrapped around drive pins for concrete spalls that are in excess of 1-1/2” deep shall be a 2” x 2” grid mesh, 14 gage wire (minimum).

C. Burlap for curing patches shall be heavyweight burlap cloth.

D. Polyethylene for curing patches shall be 6 mil polyethylene plastic sheet.

E. Duct tape (if used) for curing patches shall be completely strippable commercial duct tape.

2.07 STEEL REINFORCEMENT

A. Galvanized Reinforcing Bars: ASTM A 615, Grade 60, deformed. Various sizes to match existing at top and bottom mats.

2.08 RELATED MATERIALS

A. Bar supports: Bolsters, chairs, spacers, and other devices for spacing, supporting, and fastening reinforcing bars. Manufacture bar supports according to CRSI’s “Manual of

Standard Practice” from steel wire or plastic. Tips of chair or bolster supports shall be plastic capped, or hot-dip galvanized.

B. Epoxy for setting dowel reinforcement into existing concrete sections: Sikadur 32, Hi-

Mod by Sika Corp. or Sikadur 33 structural paste adhesive by Sika Corp. or approved equal.

C. Bonding agent: Refer to mortar or concrete repair manufacturer’s recommendations.

PART 3 – EXECUTION

3.01 GENERAL

A. Remove all equipment, fixtures, and fittings at areas to receive concrete repairs, as indicated on the drawings and as required.

B. Verify location and extent of spalled, delaminated, cracked, and otherwise deteriorated concrete shown on the Drawings. Any discrepancies with the drawings shall be brought to the attention of the Owner.

C. Identify perimeter of deteriorated areas of concrete scheduled to be removed/repaired with spray paint.

D. Provide all devices (including heaters and ventilation) necessary to maintain areas at the proper temperature and humidity for the curing of repair mortar, concrete, epoxy, and sealant materials.

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E. No concrete repair work shall be executed when the temperature in the work areas has dropped below 45 degrees Fahrenheit, unless heated. Consult the manufacturers of the materials for proper application and storage procedures.

3.02 CONCRETE SPALL MORTAR AND CONCRETE REPAIRS

A. Remove all areas of deteriorated, delaminating, debonded, spalled or otherwise damaged concrete from existing surfaces including structural concrete slabs, and concrete encasement of structural framing, as required to install the new work. Do not cut existing reinforcing steel bars. Removal of deteriorated concrete and surface preparation shall be completed as recommended by the repair materials manufacturer.

B. Define all repair areas with 1/4” deep perimeter saw cut, maintaining a polygon area.

Undercut or “key” in spall repair edges on at least two opposite sides to mechanically retain the repair. Cuts shall not overlap at corners.

C. Prepare the surface of the existing concrete to receive the repair mortar or concrete.

Provide a 1/8” minimum aggressive surface profile with fractured aggregate. Tool marks should be visible. Examine substrate for cracks and treat with specified crack repair procedure.

D. Completely remove all dust, grease and other impurities via compressed air and wire brushes, chipping, grinding or other methods as required to achieve acceptable bonding surfaces. Dampen the existing surface area with clean potable water, to obtain saturated-surface-dry (SSD) conditions.

E. Apply coating/bonding agent to substrate surfaces and reinforcing steel as recommended by the repair materials manufacturer. Slurry scrub profiling mortar into prepared damp substrates.

F. Install repair mortar or concrete to properly prepared areas. Mix repair mortar or concrete in accordance with the material manufacturer’s instructions. At spall repairs with a depth greater than 1-1/2”, mix in 3/8” coarse aggregate as required by the manufacturer. Utilize the manufacturer’s recommended mix rates. Extend profiling mortars in strict accordance with manufacturer’s directions.

G. Spall locations that exceed 1-1/2” depth shall have drive pins installed into the substrate.

Drive pins shall be spaced 8” on center, with a minimum of 2 pins per spall, and have stainless steel wire or hot-dip galvanized wire wrapped about the base prior to installation to act as a reinforcement line upon installation of the patching materials. Large spall sectional loss shall include hooked dowel reinforcement.

H. Finish the repairs flush with the existing surfaces. Ensure that the surface, texture, profile and color of the repair areas matches the surrounding surfaces. Do not feather edge repairs but install in 1/4” minimum applications or as otherwise limited by each materials manufacturer’s limitations.

I. Provide for proper cure of patch as recommended by the repair material manufacturer.

At a minimum, curing shall consist of wet burlap placed over the repair area, continuously wetted to provide a constantly moist burlap and enclosed with polyethylene, 037000 - 7 duct taped to the adjacent surfaces. Curing materials shall remain in place for 7 days or as recommended by material’s manufacturer.

3.03 REINFORCING STEEL AT SPALL MORTAR AND CONCRETE REPAIR

A. Perform surface preparation as recommended by the repair mortar manufacturer. Should reinforcing bars be encountered, perform the following work:

1. Reinforcing steel bars exposed which have rust that extends to the back of the bar shall have the concrete removed from the full circumference of the bars to provide a minimum clearance of 3/4” all around if surface rust extends to the back side of the bar. If more than one half of any bar diameter is exposed during demolition, remove concrete from the full circumference of bar with minimum

3/4” clearance all around.

2. Reinforcing steel must be mechanically cleaned and free of rust, scale, grease, oil and other bond-inhibiting matter in accordance with SSPC – SP11, at a minimum and as required by the rebar bonding agent manufacturer. This can be accomplished using hand-held wire brush, power tools or similar approved methods.

3. After cleaning of reinforcement to bare metal, thoroughly examine and determine section loss. Bars with 15% or greater section loss shall receive supplemental galvanized steel. New steel bars shall be placed and tied along side of existing corroded bar at same depth where possible. Bar lap shall be developed 20 bar diameters, each end, beyond point of corroded bar. Remove additional concrete as required to fit bar and develop lap lengths. New bar diameter shall match existing nominal bar diameter prior to corrosion or as directed by engineer. In all cases, new reinforcement shall have a minimum concrete or mortar cover of 1-

1/2 inches.

4. At discontinuous ends of reinforcement or where 20 bar diameter lap is not possible, supplemental reinforcement may be drilled and epoxied into the substrate adjacent to existing corroded bars. Drill hole 1/4” diameter larger than bar diameter at a depth 10 times the bar diameter. Maintain a minimum 2-inch cover and edge distance at all drilled hole locations. Clean hole and fill with a high modulus, high strength, structural epoxy paste adhesive conforming to

ASTM C-881 and AASHTO M-235 specifications.

5. Apply bonding agent to all exposed steel surfaces using brushes in strict accordance with the bonding agent manufacturer’s written requirements.

6. Apply repair mortar or concrete as specified and recommended by the manufacturer. Allow to partially cure and finish to match the surrounding surface.

7. Clean areas adjacent to the repair area prior to curing with a moist sponge or cloth immediately after application.

8. Apply all curing materials and techniques as specified in this section.

3.04 EPOXY INJECTION REPAIRS AT STRUCTURAL CONCRETE SLABS

A. Clean the existing crack and adjacent areas of all loose materials with high-pressure air to blow the crack clean.

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B. Cracks smaller than 1/4-inch width shall be routed or “veed” by saw-cutting to accommodate insertion of entry ports and application of cap seal. Drilling of cracks for injection ports must be accomplished using a vacuum attached swivel drill chuck, or similar.

C. Install tape along perimeters of crack to limit the amount of cap seal which contacts concrete. Spread cap seal material a minimum of 1/2-inch past the crack termination, each side. The surface sealer shall have a uniform thickness of 1/8-inch minimum to

3/16-inch maximum.

D. Inject epoxy starting at the lowest entry port, until clearly visible at the next entry port indicating that crack void is filled to that point. Pressure of injections of grout shall not exceed 200 psi unless instructed otherwise by the Engineer. Spacing of injection ports shall not exceed thickness of substrate. It is recommended that ports be placed at a spacing equal to one-half the substrate thickness. Obtain Engineer’s approval of port spacing which does not comply with this recommendation.

E. Immediately following injection at each entry port, plug port to prevent escape of injected epoxy.

F. Repeat until crack void is completely filled. Confine any spills and collect with an absorbent material.

G. Allow crack repair material to properly cure as recommended by the material manufacturer.

H. Remove all traces of cap seal, tape and associated residue from concrete surfaces, using sharp sided tools such as a putty knife or trowel, or by mechanical wheel.

3.05 INSTALLATION OF GALVANIC ANODES AT SPALL MORTAR AND CONCRETE

REPAIR AREAS

A. Anodes shall be installed inside each spall repair area adjacent to the repair edges.

B. Space anodes 18-inches on center typically, or a maximum spacing of 24-inches on center.

C. Anodes shall be securely tied to prepared reinforcing steel.

D. Maintain a minimum mortar…