Atch_07_Spec_Section_32_01_29_Spall_Repair.doc

MAINTAIN/REPAIR PAVEMENTS IDIQ

IFB No.: F26600-99-R-C118

RKMF 98-0105

Contract No.:

PAVING IDIQ

Solicitation: FA4861-16-R-A300

SECTION 32 01 29

PATCHING OF RIGID PAVEMENTS

1. PART 1 - GENERAL

1.1. SCOPE: This section covers partial and full depth patching of PCC pavements.

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

Federal Specifications (FS):

SS-S-200 (E)

Sealants, Joint, Two-Component, Jet-Blast-Resistant, Cold-Applied, for Portland Cement Concrete Pavement

AASHTO M 182

Cloth, Burlap, Jute (or Kenaf)

U. S. Army Corps of Engineers Handbook for Concrete and Cement:

CRD-C 104-80

Calculation of the Fineness Modulus of Aggregate

CRD-C 300-90

Membrane-Forming Compounds for Curing Concrete

CRD-C 400-63

Water for Use in Mixing or Curing Concrete

American Society for Testing and Materials (ASTM) Standards:

C 31

(1996) Making and Curing Concrete Test Specimens in the Field

C 78

(1994) Flexural Strength of Concrete (Using Simple BeamWith

Third-Point Loading)

C 136

(1996) Sieve Analysis of Fine and Coarse Aggregates

C 143

(1990) Slump of Portland Cement Concrete

C 150

(1996) Portland Cement

C 171

Sheet Materials for Curing Concrete

C 173

Air Content of Freshly Mixed Concrete by the Volumetric Method

C 192

Making and Curing Concrete Test Specimens in the Laboratory

C 231

Air Content of Freshly Mixed Concrete by the Pressure Method

C 260

Air-Entraining Admixtures for Concrete

D 75

Sampling Aggregates

1.3. DESIGN: The concrete mixtures shall be designed to produce concrete having a minimum average flexural strength of 600 psi at 7 days of age, and 750 psi at 28 days of age, determined in conformance with ASTM C 78, using standard 6- by 6-inch beam specimens. Alternately, compressive strengths, as determined with ASTM C 39, may be used. The concrete mixtures shall be designed to produce concrete having a minimum average compressive strength of 5000 psi at 7 days of age, and 7000 psi at 28 days of age. The concrete mixture shall be designed to secure an air content by volume of 4 percent, plus or minus 1-1/2 percent, based on measurements made on concrete immediately after discharge from the mixer in conformance with ASTM C 231.

1.4. EQUIPMENT; APPROVAL AND MAINTENANCE: Dependable and sufficient equipment that is appropriate and adequate to accomplish the work specified shall be assembled at the site of the work a sufficient time before the start of paving to permit thorough inspection, calibration of weighing and measuring devices, adjustment of parts, and the making of any repairs that may be required. The equipment shall be maintained in good working condition.

1.5. SAMPLING AND TESTING OF MATERIALS: Sampling and testing shall be performed by a certified and licensed commercial laboratory as determined by the state of Nevada. All testing shall be performed at no additional cost to the Government.

1.5.1. Cement: Cement shall be tested as prescribed in the referenced specification under which it is furnished. Cement may be accepted on the basis of mill tests and the manufacturer's certification of compliance with the specification, provided the cement is the product of a mill with a record for the production of high-quality cement for the past 3 years.

1.5.2. Aggregate: Aggregate samples for laboratory testing shall be taken in conformance with ASTM D 75 and tested in accordance with ASTM C 136.

1.5.3. Joint-Sealing Materials: See SECTION 2592, FIELD MOLDED SEALANTS FOR SEALING JOINTS IN RIGID PAVEMENTS.

1.5.4. Epoxy Resin Grout: Epoxy resin grout shall be tested for conformance with ASTM C 881.

1.6. SUBMITTALS:

Mix Design: The Contractor shall develop and submit proposed mix design for partial and full-depth patching prior to placement. The mix design shall indicate the weight of each ingredient of the mixture and gradations. No concrete shall be placed prior to approval of the proposed mix design. No deviation from the approved mix design will be permitted without prior approval.

Laboratory Test Results: Three copies of test results shall be submitted to the Contracting Officer for approval and should include a wet signature.

Certificates of Compliance: Manufacturer's certificates of compliance shall be submitted for cement. Submit product information and manufacturer's recommendations for the epoxy resin grout. No materials shall be placed without prior approval from the Contracting Officer.

1.7. DELIVERY AND STORAGE OF MATERIALS:

1.7.1. Cement: Cement may be furnished in bulk or in suitable bags used for packaging cements and shall be stored in a manner to prevent absorption of moisture.

1.7.2. Aggregates: Aggregates shall be handled and stored in a manner to avoid breakage, segregation, or contamination by foreign materials.

1.7.3. Epoxy-Resin Grout: Epoxy resin grout shall be delivered to the site in such manner as to avoid damage or loss. Storage areas shall be in a windowless and weatherproof, but ventilated, insulated noncombustible building, with provision for conditioning the material to 70 degrees F to 85 degrees F for a period of 48 hours prior to use. The ambient temperature in the storage area of the epoxy materials shall at no time be higher than 100 degrees F.

1.8. WEATHER LIMITATIONS: Concrete shall not be placed when weather conditions detrimentally affect the quality of the finished product. No concrete shall be placed when the air temperature is below 40 degrees F. in the shade. When air temperature is likely to exceed 90 degrees F., the concrete shall have a temperature not exceeding 90 degrees F. when deposited, and the surface of such placed concrete shall be kept damp with a water fog until the approved curing medium is applied.

2. PART 2 - PRODUCTS

2.1. MATERIALS:

2.1.1. Coarse Aggregate:

2.1.1.1. Composition: Coarse aggregate shall consist of gravel, crushed gravel, crushed stone, or a combination thereof, or crushed blast-furnace slag.

2.1.1.2. Quality: Aggregate as delivered to the mixers shall consist of clean, hard, unweathered, and uncoated particles. Dust and other coatings shall be removed from the coarse aggregates by adequate washing.

2.1.1.3. Particle Shape: Particles of the coarse aggregate shall be generally spherical or cubical in shape.

2.1.1.4. Size and Grading: The nominal maximum size of the coarse aggregate shall be 1 1/2 inches. The grading of the coarse aggregate within the separated size groups, when tested in accordance with ASTM C 136, shall conform to the following requirements as delivered to the mixer:

COARSE AGGREGATE GRADATION

(Percentage by Weight Passing Individual Sieves)

Sieve Size, U. S. Standard No. 4 to 3/4-inch to

Square Mesh 3/4-inch 1-1/2 inches

2 inches 100

1-1/2 inches 90-100

1 inch 100 20-54

3/4-inch 90-100 0-14

1/2-inch -- --

3/8-inch 20-54 0-6

No. 4 0-10

No. 8 0-6

2.1.2. Fine Aggregate:

2.1.2.1. Composition: Fine aggregate shall consist of either natural sand, manufactured sand, or a combination of natural and manufactured sand, and shall be composed of clean, hard, durable particles.

2.1.2.2. Particle Shape: Particles of the fine aggregate shall be generally spherical or cubical in shape.

2.1.2.3. Grading: Grading of the fine aggregate, as delivered to the mixer, shall conform to the following requirements when tested in accordance with ASTM C 136:

Sieve Designation, U. S. Standard Cumulative Percentage by Weight

Square Mesh Passing Individual Sieves

3/8 inch 100

No. 4 94-100

No. 8 80-90

No. 16 60-80

No. 30 30-60

No. 50 10-30

No. 100 2-10

In addition, the fine aggregate, as delivered to the mixer, shall have a fineness modulus of not less than 2.40 nor more than 2.90. The grading of the fine aggregate also shall be controlled so that the fineness moduli of at least nine of ten samples of the fine aggregate, as delivered to the mixer, will not vary more than 0.15 from the average fineness moduli of all samples previously taken. The fineness modulus shall be determined by CRD-C 104.

2.1.3. Air-Entraining Admixture: Air-entraining admixture shall conform to ASTM C 260.

2.1.4. Cement: Cement shall be Portland Cement Concrete conforming to ASTM C 150, Type V.

2.1.5. Curing Materials:

2.1.5.1. Burlap shall conform to AASHTO M 182.

2.1.5.2. Membrane-forming curing compound shall be a pigmented type conforming to Corps of Engineers Specification CRD-C 300.

2.1.5.3. Waterproof blanket materials shall conform to ASTM C 171, Type optional, color white.

2.1.6. Water: Water shall be clean, fresh, and free from injurious amounts of oil, acid, salt, alkali, organic matter, or other deleterious substances. Water approved by Public Health authorities for domestic consumption may be accepted for use without being tested. Water that is of questionable quality, in the opinion of the Contracting Officer, shall be tested in accordance with CRD-C 400.

2.1.7. Epoxy Resin Grout: Epoxy-resin grout shall be a two-part component material formulated to meet the requirements of ASTM C 881, Type I or Type II. Type I material shall be used when pavement, materials, or atmospheric temperatures are 70 degrees or above. Type II material shall be used otherwise.

2.1.8. Dowels shall be fabricated or cut to length at the shop or mill before delivery to the site. Dowels shall be free of loose flaky rust and loose scale and shall be clean and straight. Dowels may be sheared to length provided that the deformation from true shape caused by shearing does not exceed 0.04 inch on the diameter of the dowel and does not extend more than 0.04 inch from the end of the dowel. Dowels shall be plain steel bars conforming to ASTM A 615, grade 40 or 60; ASTM A 616, grade 50 or 60; or ASTM A 617, grade 40 or 60; or shall be steel pipe conforming to ASTM A 120, extra strong, as indicated.

2.1.9. Tie Bars: Tie bars shall be deformed steel bars conforming to ASTM A 615, A 616, or A 617, and of the sizes and dimensions indicated. Deformed rail steel bars and high-strength billet or axle steel bars, grade 60 or higher, shall not be used for bars that are bent and straightened during construction.

2.1.10. Epoxy Resin for Embedding Dowels: All epoxy resin materials shall be two-component materials conforming to the requirements of ASTM C 881, class as appropriate for each application temperature to be encountered, except that in addition, the materials shall have a 24-hour absorption not greater than 1 percent, and shall be Type III materials meeting these requirements: (a) the bond strength at 14 days (moist cure) shall be at least 1000 psi, and (b) the volatile content, cured system, shall not exceed 3 percent. Grade 3 shall be used for embedding dowels in hardened concrete.

3. PART 3 - EXECUTION

3.1. CONDITIONING OF EXISTING PAVEMENT:

3.1.1. Partial Depth Patching:

3.1.1.1. Preparation of Existing Surfaces: In the area to be patched, the surface of the existing concrete shall be removed to a minimum depth of 2 inches and to such additional depth where necessary to expose a surface of sound, unweathered concrete that is uncontaminated by oils, greases, or deicing salts or solutions. A vertical saw cut at least 3 inches deep shall be made a minimum of 3 inches outside of the area to be repaired. The surface shall be thoroughly cleaned by sweeping and blowing with compressed air. Prior to placing concrete, areas showing traces of oils or grease shall be cleaned by sandblasting. Before placing concrete, dampen surface with a fog spray; do not saturate.

3.1.1.2. Preparation of Joints: Joint-sealing and expansion-joint materials shall be removed flush with the prepared surface, and, if on the pavement surface to be patched, shall be removed by sandblasting. The use of solvents will not be permitted. Care shall be used to prevent bonding of the adjacent concrete slabs at the location of the existing joints. Maintenance of these existing joints shall be accomplished by the use of fiberboard or other approved inserts of appropriate dimensions.

3.1.1.3. Bonding Course: Prior to placing concrete, the previously prepared surfaces shall be washed with a high-pressure water jet followed by compressed air to remove free water. The clean surface shall be coated with a 20 to 40 mil thick film of the epoxy-resin grout. The epoxy resin grout shall be placed in one application, just prior to concrete placement, with the use of mechanical combination, mixing and spraying equipment, or shall be applied in two coats with stiff brushes. The first brush coat shall be scrubbed into the concrete surface, followed by an additional brush coat to obtain the required thickness. When the brush method is used, the initial coat may be allowed to dry; however, the final coat shall be applied just prior to placement of the concrete. Epoxy resin grout components shall be mixed in the proportions recommended by the manufacturer.

3.1.2. Full Depth Patching:

3.1.2.1. Concrete removal: Sawcut to full depth along the selected boundaries of the repair area. Dowels may be encountered at control joints. Remove the concrete section by lifting it out in one or more pieces using chains and lift pins or other devices. If the existing pavement outside the repair boundary is spalled during removal operations, the Contractor shall make a new sawcut boundary to remove the damaged area.

3.1.2.2. Subbase Repair: If the subbase is disturbed or loose, that portion shall be removed. No new subbase material shall be added, and the low portion shall be filled with the new concrete.

3.1.2.3. Dowel Placement: Place dowels and deformed rebar according to the applicable details and specifications.

3.2. BATCHING, MIXING AND PROPORTIONING:

3.2.1. Equipment: Mixing equipment shall be capable of combining the aggregate, cement, admixture, and water into a uniform mixture and discharging this mixture without segregation.

3.2.2. Conveying: Concrete shall be conveyed from mixer to repair area as rapidly as practicable by methods that will prevent segregation or loss of ingredients.

3.2.3. Facilities for Sampling: The Contractor shall provide suitable facilities for readily obtaining representative samples of aggregate and concrete for uniformity test purposes. Necessary platforms, tools, and equipment for obtaining samples shall be furnished by the Contractor.

3.2.4. Mix Proportions: The proportions of materials entering into the concrete mixtures shall be in accordance with the approved job-mix formula. The proportions shall be changed whenever necessary to maintain the workability, strength, and standard of quality required, and to meet the varying conditions encountered during the construction. However, no changes will be made without prior approval by the contracting officer.

3.2.5. Measurement: Equipment necessary to measure and control the amount of each material in each batch of concrete shall be provided. Bulk cement shall be weighed, but cement in unopened bags as packed by the manufacturer may be used without weighing. If bagged cement is used, batches shall be proportioned so that fractional bags will not be required. Mixing water and air-entraining admixtures may be measured by volume or by weight. One gallon of water will be considered as weighing 8.33 pounds.

3.2.6. Workability: The slump of the concrete shall be maintained at the lowest practicable value, not exceeding 2 inches when tested in accordance with ASTM C 143.

3.3. PLACING: Concrete shall be placed before the concrete has obtained its initial set, and while the epoxy-resinbonding course is tacky. The temperature of the concrete, as deposited in the form, shall be not less than 40 degrees F. nor more than 90 degrees F. Concrete shall be deposited in such manner as to require a minimum of rehandling, and the placement shall be in such a manner so as to least disturb the epoxy-resin grout. The placing of concrete shall be rapid and continuous for each area. Workmen shall not walk on the concrete during placing and finishing operations. The concrete shall be thoroughly consolidated by tamping or by means of suitable vibrating equipment. During hot weather, where the daytime high is 85 degrees F or greater, the concrete shall be placed at the coolest time of day practicable.

3.4. FIELD TEST SPECIMENS: Concrete samples shall be furnished by the Contractor, and shall be taken in the field and tested to determine the slump, air content, and strength of the concrete. Test beams or cylinders shall be made for determining conformance with the strength requirements of these specifications and, when required, for determining the time at which pavements may be placed in service. The air content shall be determined in conformance with ASTM C 173. Test beams shall be molded and cured in conformance with ASTM C 31 and as specified below. The Contractor shall furnish all materials, labor, and facilities required for molding, curing, and protecting specimens at the site and under the supervision of the Contracting Officer. Curing facilities for specimens shall include furnishing and operating water tanks equipped with temperature-control devices that will automatically maintain the temperature of the water at 73 degrees F. plus or minus 5 degrees F. The Contractor shall also furnish and maintain at the site, boxes or other facilities suitable for storing the specimens while in the mold at a temperature of 73 degrees F. plus or minus 10 degrees F. Tests of the fresh concrete and of the hardened concrete beams shall be made by and at the expense of the Contractor.

3.4.1. Specimens for Strength Tests: Flexural test beams or cylinders shall be made each shift that concrete is placed. Each group of test beams shall be molded from the same batch of concrete, and shall consist of a sufficient number of specimens to provide two flexural-strength or compressive strength tests at each test age. One group of specimens shall be made during the first half of each shift, and the other during the last portion of the shift. However, at the start of paving operations and each time the aggregate source, aggregate characteristics, or mix design is changed, one additional set of test beams shall be made. When the average strength of the beams made during a shift do not reach the specified strength at the specified ages, the concrete patches represented by those test results may be removed and replaced at no additional cost to the Government.

3.5. FINISHING operations shall be started immediately after placement of the concrete. The finished surfaces of patched areas shall have a surface texture approximating that of the adjacent undisturbed pavements.

3.6. CURING:

3.6.1. General: Concrete shall be cured by protection against loss of moisture and rapid temperature changes for a period of not less than 7 days from the beginning of the curing operation. Unhardened concrete shall be protected from rain and flowing water. The Contractor shall have all equipment needed for adequate curing and protection of the concrete on hand and ready to install before actual concrete placement begins. Failure to comply with curing requirements shall be cause for immediate suspension of concreting operations.

3.6.2. Burlap Curing: Immediately after the finishing operations have been completed and the concrete has set sufficiently to prevent marring the surface, the entire surface of the newly laid concrete shall be covered with approved wetted burlap that shall be kept wet for a period of not less than 24 hours. The surface of the newly laid concrete shall be kept moist until the burlap coverings are in place. Curing of the concrete shall be continued for the duration of the required curing period by this method or one of the methods specified below.

3.6.3. Waterproof-Paper Blankets or Impermeable Sheets: Immediately after removing the covering used for initial curing, the exposed concrete surfaces shall be moistened with a fine spray of water and then covered with waterproof-paper blankets, polyethylene-coated-burlap blankets, or impermeable sheets. Burlap of polyethylene-coated burlap shall be saturated with water before placing. Sheets shall be placed with the light-colored side up. Sheets shall overlap not less than 12 inches with edges taped or secured to form a completely closed joint. Coverings shall be weighted down to prevent displacement or billowing from winds. Tears or holes appearing during the curing period shall be immediately repaired by patching.

3.6.4. Membrane-forming curing compound shall be applied immediately to exposed concrete surfaces after removing burlap coverings. The curing compound shall be applied with an overlapping coverage that will give a two-coat application at a coverage of not more than 200 square feet per gallon for both coats. When application is made by hand-operated sprayers, the second coat shall be applied in a direction approximately at right angles to the first coat. Concrete shall be properly cured at joints, but no curing compound shall enter joints that are to be sealed with joint-sealing compounds. The compound shall form a uniform, continuous, cohesive film that will not check, crack, or peel, and that will be free from pinholes and other imperfections. Concrete surfaces that are subjected to heavy rainfall within 3 hours after the curing compound has been applied shall be resprayed at the coverage specified above and at no additional cost to the Government. Areas covered with curing compound that are damaged by pedestrian and vehicular traffic or by subsequent construction operations within the specified curing period shall be resprayed at no additional cost to the Government.

3.7. FINISH TOLERANCE: The finished surfaces of patched areas shall meet the grade of the adjoining pavements and shall not deviate more than 1/8-inch from a true plan surface within the patched area.

3.8. PAVEMENT PROTECTION: The Contractor shall protect the patched areas against damage prior to final acceptance of the work by the Government. Traffic shall be excluded from the patched areas by erecting and maintaining barricades and signs until the completion of the curing period of the concrete.

3.9. JOINTS shall conform in detail and be in alignment with the existing joints. After curing of the concrete, the joints shall be primed if and as recommended by the sealant formulator and shall then be sealed with jet-fuel-resistant joint-sealing material. Defective joints shall be satisfactorily replaced.

END OF SECTION

Page 32 01 29-1 (22 Mar 99)

Patching Rigid Pavements

Page 32 01 29-10 (7 Feb 2016)