15_FA3047-15-R-0059_Attachments.pdf

FA3047-15-R-0059

ATTACHMENT 1

Statement of Work (SOW)

STATEMENT OF WORK

MPLS 12-0013A

Repair Pavers at Parade Field

JBSA – LACKLAND

Statement of Work. Rev. 11Aug15 Page 1 of 35

1. PROJECT NUMBER/TITLE

MPLS 12-0013A - Repair Pavers at Parade Field

2. CONTRACTING OFFICER (CO)

The Contractor’s responsibility is directly to the Contracting Officer. Bring to the attention of the contracting Officer any change or deviation to the scope of work for approval. In no case shall changes to the scope be made at the Activity level or by any person other than the Contracting Officer.

3. GENERAL DESCRIPTION

This is a Design-build project. The Contractor shall provide design documents as required by this Statement of Work (SOW) to include but not limited to: equipment selection, investigations, design surveys, calculations validations, and as-built drawings as required. Upon approval of the 100% design stamped drawings the Government shall issue a construction Notice to Proceed (NTP) to the Contractor. The proposed system requirements in section 6 are developed by the Government and may be enhanced and upgraded by the Contractor for value engineering purposes.

The Contractor is responsible for conducting a pre-design survey on the areas where work will take place to assess site conditions.

4. BACKGROUND

Repairing current sidewalks is required to bring the current sidewalks up to modern standards and create a safe environment.

5. GENERAL REQUIREMENTS

The Parade Field is located on Bong Ave, Joint Base San Antonio Lackland Air Force Base, TX 78236. Every Thursday and Friday new airmen participating in the basic military training graduation parade occupy the field.

The Parade Field is open 5 days a week all year long except Thursdays and Fridays. The Parade Field area has direct access to adjacent parking lots and will be available for use by the Contractor while the Parade Field is closed. During the construction phase of this project the contractor will not have access to the Parade Field on Thursdays and Fridays. Upon coordination of a time and date by the 502 Civil Engineer Squadron (CES) Project Manager (PM), contractor shall ensure that government personnel are able to access the Parade Field and perform their task in a safe and secure environment.

The contractor shall coordinate with the 502 CES PM prior to mobilization to allow the users enough time to vacate the project area and coordinate with Lackland Heritage Museum Operations patrons. The contractor shall make all effort to minimize any adverse effect to the normal operations of Parade Field beyond the boundaries of the project area.

Construction Requirements: All work shall be in conformance with the drawings and specifications provided by the Contractor, including the furnishing of all materials, labor, plants, Statement of Work. Rev. 11Aug15 Page 2 of 35 tools, equipment, and services necessary and incidental there unto. The Contractor shall coordinate all work with the PM and the CO (who in turn will coordinate with all pertinent parties) so as to minimize outages and interruption to mission operations. The work required to be performed by the Contractor consists of, but is not limited to, the following:

Normal Working Hours: The normal working hours at JBSA are Monday through Friday from 7:30 a.m. to 4.30 p.m. excluding holidays. However, the contractor will be restricted access to the work site on Thursdays and Fridays. Requests to work outside of normal working hours shall be submitted to the Contracting Officer for permission in writing, at least three (3) working days in advance. Approval to work outside Normal Hours is at the Contracting Officer’s discretion.

6. PROJECT REQUIREMENTS

6.1. REPAIR PAVERS AT PARADE FIELD

6.1.1. The contractor shall identify and comply with all applicable (1) federal, state (Texas), local (San Antonio) as well as Department of Defense (DoD), Air Force, and JBSA - Lackland statutes, instructions, manuals, handbooks, regulations, guidance, policy letters, and rules (including all changes and amendments), and (2) Presidential Executive Orders, in effect on the date of issuance of this contract

6.2.1.1 Design: The contractor will provide all personnel, equipment, materials, supplies, labor, supervision and other items and services to install “poured in place” sidewalks with pavers at the Parade Field, JBSA Lackland, TX. Contractor shall design paver pattern as running bond design.

The overall scope of work (SOW) includes demolition of existing sidewalk in the construction area and placing a new ADA compliant sidewalk with pavers. The contractor shall be responsible for developing design analysis, plans, and specifications to accomplish the provisions of this SOW.

6.2.1.2. Install double curb flush unitary poured in place surfacing to include compacted base material and concrete slab on grade. Install 2 curbing (4 inches curb width x inside depth 3 inches x 5 feet 8 inches wide x 1 foot depth from top of curb to base) around sidewalk perimeter. Install two (2) concrete ramps compliant with the Americans with Disabilities Act (ADA); see Appendix A for ramps locations. The contractor shall obtain a digging permit from the Installation Civil Engineers before excavating prior to commencement of work.

6.2.1.3. Contractor shall provide and install all necessary components for deep design paver sidewalks.

6.2.1.4. Developing a plot plan that shows proper drainage and grade soil to avoid water build-up on site, where conditions permit.

6.2.1.5. Contractor shall provide concrete sidewalk surfaces that show splice locations and splice lengths on the drawings. Standardize use of a few sizes of rebar, between bars that are of similar size.

6.2.1.6. Contractor shall provide designs and type materials used for compacted subgrade, sub-base and base course for concrete sidewalk for pavers on grade foundation.

Statement of Work. Rev. 11Aug15 Page 3 of 35

6.2.1.7. Contractor shall comply with the Americans with Disabilities Act sidewalk.

6.2.1.8. Contractor shall provide ADA parking lot markings/signs as needed.

6.2.1.9. Compaction. Subgrade materials shall be compacted to the required density and moisture content as shown below, unless otherwise shown on the plans.

6.2.1.10. Contractor shall place sod 4 feet to each side of the sidewalk.

6.2.1.11. Contractor shall design subbase, base and sidewalk to account for considerable expansion and contraction of existing soils. The current design broke in several locations due to the constant movement of the earth and damage due to storm water flow.

6.2.1.12. Contractor shall ensure curb joints line up with sidewalk joints. The curb joints must line up with the sidewalk joints.

7. The Designer of Record (DOR) shall use the Unified Facilities Guide Specifications (UFGS) and the requirements contained in this SOW to fully develop the technical specifications and construction drawings. The technical criteria contained and cited in this SOW and UFGS establish minimum standards for the design and construction quality.

8. The contractor shall be responsible for preparing, filing, testing, and paying for any fees necessary to obtain all necessary permits to meet the provisions of this SOW. All testing and/or permitting fees shall be included as part of the contractor’s proposal.

9. DRAWINGS

Refer to paragraph 54 for complete details.

10. The contractor shall coordinate with the 502 CES PM and receive approval in advance prior to mobilizing for laydown area prior to beginning construction.

11. DEMOLITION

11.1. The contractor shall obtain a digging permit before excavating prior to work beginning from the Installation Civil Engineers.

11.1.1. Manifests shall be requested 2 weeks prior to start of demo (soil manifest, concrete manifest, debris manifests)

11.1.2. Contractor shall demo existing sidewalks, remove top soil and old pavers in the Parade Field and save for reuse for sub-base or base course.

11.1.3. All waste materials demolished shall be removed from the government property to an approved landfill site.

11.1.4. Contractor shall carefully remove existing sidewalks around the Parade Field vintage military aircraft. Parade Field vintage military aircraft damaged, chipped paint, bent, or broken shall be repaired or replaced to match original conditions.

Statement of Work. Rev. 11Aug15 Page 4 of 35

11.1.5. Contractor shall maintain/cut laydown area/construction sites presentable to a minimum of four (4) feet outside fences and all interior ground maintenance with in laydown area until project is completed.

11.1.6. Contractor shall cover dirt to be reused. Any dirt not to be reused shall be removed from site and base, following environmental guidelines (Appendix B).

11.1.7. Contractor shall maintain a safe, clean, and dust free environment to prevent any adverse effect to the normal operations of the Parade Field and/or any other adjacent areas.

11.1.8. Contractor shall protect government equipment and property from damage during construction. Contractor is responsible for properly documenting the condition of the property prior to the start of construction. Contractor shall be responsible for repairing any damages to government property due to contractor’s negligence, at its own cost.

11.1.9. All demolished materials at the conclusion of the project will become the property of the contractor and shall be removed off-site, disposed identification and listing of hazardous waste, in accordance with (IAW) all applicable local, state, and federal laws. The hazardous waste program regulates commercial businesses as well as federal, State, and including the Resource Conservation and Recovery Act (RCRA).

11.1.10. All dirt/waste/spoils are required to be tested, manifested and taken off base.

11.1.11. Laydown yard and parking to be determined and approved by Project Manager before NTP Construction.

11.1.12 Due to the high visibility and use of the parade field, a 6 foot chain-link fence will be required at the beginning of any demolition/construction work. Fence requirements are in sections

22.2 and 22.3.

12. CONSTRUCTION

The work performed by the contractor shall result in complete and fully functioning systems consisting of, but not limited to, the following principal items:

13. NEW WORK

13.1. Compaction. Subgrade materials shall be compacted to the required density and moisture content as shown below, unless otherwise shown on the plans:

Subgrade Material Density Moisture Content:

PI ≤ 20 ≥ 95% of Max Dry Density - 2% of Opt. or greater PI > 20 ≥ 95% of Max Dry Density ≥ Opt. Moisture

The maximum dry density and optimum moisture content shall be determined in accordance with TxDOT Test Method Tex-114-E. Tests for in place density shall be made in accordance with

Statement of Work. Rev. 11Aug15 Page 5 of 35

TxDOT Test Method Tex-115-E and within 24 hours after compacting operations are completed.

If the material fails to meet the density specified, it shall be re-worked as necessary to obtain the density required.

For materials with a PI > 20, just prior to placing any base materials or stabilization, the top 3 inches of compacted subgrade shall be tested for density and moisture content. If tests show the density to be more than 2% below the specified minimum or the moisture content to be more than 3% above or below the optimum, the course shall be reworked as necessary to obtain the specified compaction and moisture content. If the material used to replace undercuts or unsuitable material contains more than 30% oversize fraction (i.e. 30% or more retained on the ¾-inch sieve) or is gap-graded (many large particles with limited small particles), the maximum density determined by Tex-114-E may not be appropriate for field compaction. If this situation is encountered, the Engineer may elect to accept the material without density testing. With the approval of the Engineer, place layers in loose lifts not to exceed 12 inches. Before and during rolling operations, bring each layer to the moisture content directed. Compact each layer until there is no evidence of further consolidation. Maintain a level layer to aid in uniform compaction. If the required stability or finish is lost for any reason, recompact and refinish the subgrade at no additional expense to the Government.

13.1.1. The contractor shall provide a project manager a list of who shall be responsible for the performance of the work. The name of this person and an alternate who shall act for the contractor when the manager is absent shall be designated in writing to the contracting officer. The contract manager or alternate shall have full authority to act for the contractor on all contract matters relating to daily operation of this contract. The contract manager or alternate shall be available between 0800-1700, Monday thru Friday except Federal holidays or when the government facility is closed for administrative reasons.

13.1.2. ADA (AMERICANS WITH DISABILITIES ACT) requirements width of 68 inches, height 12 inches. (For more details see appendix C)

13.1.3. Sidewalk design widths to be at least 1.73 m (68 inches) wide, larger design widths can accommodate more pedestrians and improve ease of access. (For more details see appendix C).

13.1.4. Be of a height equal to the full depth of the finished sidewalk.

13.1.5. Set forms for sidewalks with the upper edge true to line and grade with an allowable tolerance of 3 mm (.12 inch) in any 3 m (10 feet) long section. Forms shall have a transverse slope of 20 mm per meter (.24 inch per feet) with the low side adjacent to the roadway or lowest elevation. Side forms shall not be removed for 12 hours after finishing has been completed.

13.1.6. Surface and thickness tolerances finished surfaces shall not vary more than 8 mm (.32 inch) from the testing edge of a 3 m (10-feet). Allowable deficiency in section thickness will be up to 6 mm (.24 inch).

13.1.7. Contractor shall install sod to a minimum of 4 feet both sides of sidewalk after trash and debris pickup on construction site and water for (4) four weeks to establish grass.

Statement of Work. Rev. 11Aug15 Page 6 of 35

13.1.8. Culvert Excavation and backfill dirt. The contractor shall grade earth to approved for construction drawings. Seed/hydromulch excavated areas and water for four (4) weeks or until grass is established.

13.1.9. Removal of Existing Sidewalk. If an existing sidewalk is to be reconstructed or repaired, remove existing sidewalk to the depths and limits shown on the plans or identified by the Engineer.

If necessary, remove adjacent soil and vegetation to prevent contamination of the sidewalk area, and place it in a windrow or stockpile. Do not damage adjacent sidewalk or other structures during removal and reconstruction operations. Remove and dispose of existing concrete and other materials from the work area.

13.1.10. Subgrade Preparation. Shape and compact subgrade to the line, grade, and cross-section shown on the plans. Mechanically tamp and sprinkle foundation when placement is directly on subgrade.

13.1.11. Sub-base Placement. A cushion, 2-inch minimum in thickness, of crusher screenings, gravel, crushed rock or flexible base material shall be spread, wetted thoroughly, tamped and leveled. The cushion shall be moist at the time the concrete is placed. The 2-inch cushion is not required where the subgrade is rock or gravel, 70% of which is rock. The Engineer shall determine if the subgrade meets the above requirement.

13.1.12. If the subgrade is undercut, or the natural ground is below “top of subgrade,” the necessary backfill shall be made with an approved material and compacted with a mechanical tamper. Hand tamping will not be permitted.

13.1.13. The foundation shall be level and uniformly compacted to prevent future settlement.

13.1.14. Reinforcement. Concrete sidewalks shall be reinforced as shown in the plans. Concrete reinforcement for sidewalks may consist of longitudinal reinforcing steel without traverse reinforcement or as specified by the manufacturer or the Engineer. Steel reinforcement may be omitted if approved by the Engineer.

13.1.15. An alternate method of reinforcing using nylon or polypropylene fibers may be used if approved by Engineer or slip-form paver equipment manufacturer. Nylon fibers shall be used at a rate of one pound (1 lb) per cubic yard or polypropylene fibers at one and a half pounds (1.5 lbs) per cubic yard, unless otherwise specified by the Engineer or slip-form paver manufacturer.

13.1.16. Joints. Unless otherwise specified on plans or as agreed to by Engineer, tooled joints with rounded edges will be placed every ten feet (10’) and will be opened with one-half inch (½”) radius by one and one-half inch (1 ½”) depth and closed by one-half inch (½”) radius by one- inch (1”) depth.

13.1.17. Expansion Joints. Provide sidewalk sections separated by pre-molded or board joint ½ inch thick, or as shown on the plans, in lengths greater than 8 feet but less than 50 feet, unless otherwise directed. Terminate workday production at an expansion joint. Expansion joint material shall also be placed where the new construction abuts the existing curbs or driveways if the

Statement of Work. Rev. 11Aug15 Page 7 of 35

Engineer deems it necessary. The expansion joint material shall be placed vertically and shall extend the full depth and width of the concrete.

13.1.18. Expansion Joint Dowels. Unless otherwise shown own the plans, a minimum of two (2) round smooth dowel bars and 18 inches in length shall be spaced 18 inches apart at each expansion joint. Dowel by code shall be thoroughly coated with hot oil asphalt or greased, so that it will not bond to the concrete. Approved types of slip joints may be used in lieu of coating ends of dowels.

13.1.19. Transverse Joints. Sidewalks shall be marked with transverse “dummy” joints as shown on detail sheets, by the use of Government approved jointing tools.

13.1.20. Curb Ramps. Curb ramps must include a detectable warning surface and conform to details shown on the plans. Confirm that abrupt changes in sidewalk elevation do not exceed ¼ inch, sidewalk cross slope does not exceed 2%, curb ramp grade does not exceed 8.3%, and flares adjacent to the ramp do not exceed 10% slope.

13.1.21. Concrete Placement. Provide a smooth, uniform surface free of debris and loose foundation material for concrete placement. Lightly sprinkle subgrade or foundation material immediately before concrete placement. Mix and place concrete in accordance with the pertinent Items. Hand-finishing is allowed for any method of construction. Finish exposed surfaces to a uniform transverse broom finish surface.

13.1.22. Finish and Curing. Provide finished work with a well-compacted mass, a surface free from voids and honeycomb, and the required true-to-line shape and grade. After finishing each portion of the sidewalk, the surface shall be textured with heavy broom finish. Within twenty minutes of broom finish, a curing compound shall be used to protect the sidewalk. The curing compound shall be of a high solid content, greater than thirty percent (+30%). All edges shall be tooled to have slight radius. Surface water retention is not acceptable. Finished surface of sidewalks shall generally be one-half inch (½ inch) to one inch (1 inch) above existing grade.

Concrete must be cured and protected from freezing temperatures for at least three (3) days.

13.1.23. Exposed Aggregate Surface. For exposed Aggregate finished sidewalks, wash concrete surface after initial set with staff bristle brush and water to remove matrix and clean each piece of exposed coarse aggregate. Unless otherwise acceptable to the Engineer, perform washing and brushing 3 - 4 hours after casting. Care shall be taken to uniformly expose about a third of each piece of coarse aggregate, removing no more of the matrix than necessary across the panel surface and as required to achieve appearance similar to adjacent existing work. After seven days, follow with a final cleaning with a mild acid solution and final rinsing with clear water.

13.1.24. Backfilling. Once sidewalk has cured, sidewalk will need to be backfilled to the full height of the sidewalk. The top 4 inches of fill shall be tamped and sloped using clean topsoil and sod. Heavy equipment must remain off sidewalks at all times.

13.2. MEASUREMENT: Sidewalks shall be measured by the cubic yards of surface area at the depth specified. ADA curb ramps shall be measured by the square foot of surface area. The unit

Statement of Work. Rev. 11Aug15 Page 8 of 35 shall consist of the curb ramp, landing, adjacent flares or side curb, and detectable warning surface as shown on the plans shall be done in a manner acceptable to the Engineer

14. MATERIALS

The contractor shall furnish materials conforming to the following:

14.1. Hydraulic Cement Concrete. Contract Specifications Federal Highway Administration design sidewalks and ADA access 3500 PSI Concrete Use Class A concrete or other concrete as specified.

Use Grade 8 course aggregate for extruded Class A concrete unless otherwise recommended by the engineer and approved during design review.

14.1.1. Reinforcing Steel. Expansion Joint Material: Provide materials that conform to the requirements of TxDOT’s DMS-6310, “Joint Sealants and Fillers”:

14.1.2. Provide preformed fiber expansion joint material that conforms to the dimensions shown on the plans. Provide preformed bituminous fiber material unless otherwise specified.

14.1.3. Provide a Class 4, 5, or 7 low-modulus silicone sealant unless otherwise directed.

14.1.4. Provide asphalt board joints that conforms to dimensions shown on the plans.

14.1.5. Provide re-bonded neoprene filler that conforms to the dimensions shown on the plans.

14.1.6. Membrane Curing Compound: Provide membrane curing compounds that conform to the requirements of TxDOT’s DMS-4650, “Hydraulic Cement Concrete Curing Materials and Evaporation Retardants.”

14.1.7. Concrete Structures. Contract Specifications SECTION 03 11 14 City of San Antonio Standard Specifications 307 Concrete Structures

14.1.8. Locations: Routing and location of sidewalks shall be indicated by plans. Grading of sidewalks shall be a minimum of two feet wider than sidewalk width on straight sections and three feet wider than sidewalk at turns. Generally, where sidewalks occur on slopes, grading shall be performed so as to result in curved contours rather than abrupt banks. Fine grading shall prevent pocketing of water. The contractor shall complete final excavation and preparation of subgrade achieving slope, drainage and compaction.

Where a sidewalk crosses a concrete driveway or walkway, the the sidewalk depth and reinforcement shall be no less than the driveway cross-sectional details shown on the plans.

15. TREES AND ROOTS

15.1. Tree Protection. Trees that are near sidewalk construction shall be protected from construction equipment through the use of fencing or boarding in accordance with City of San Antonio Tree Protection Details – Tree Preservation Standard Details 1.1.3, “Level II A Fence Protection,” 1.1.4, “Level II B Fence Protection,” or as shown on the plans. Whenever possible, the entire drip line of the tree should be protected from construction activities in accordance with Tree Preservation Standard Details 1.1.2, “Level I & Fence Protection.” Do not park equipment or vehicles within 30 feet of a tree truck unless it is paved.

Statement of Work. Rev. 11Aug15 Page 9 of 35

15.1.1. Root Barriers. When shown on the plans, install root barriers near the edge of the sidewalk to reduce potential future damage to the sidewalk in accordance with the locations and depths shown on the plans. Unless otherwise shown on the plans, the root barrier shall be thermoplastic panels or sheets.

15.1.2. Root Damage to Existing Sidewalks. When roots have damaged the sidewalk and repairs are undertaken, the tree roots causing the damage shall be removed. Unless otherwise shown on the plans, contact the Contracting Officer to review the trees affected before sidewalk reconstruction begins. The Contracting Officer will identify roots to be removed and branches to be pruned, if required. Utilize equipment that will provide a sharp clean cut to minimize damage to the tree roots and branches. Prune the tree in accordance with the Contracting Officer’s requirements.

16. CONCRETE CURING MATERIALS

16.1.1. Impervious Sheet Materials Impervious sheet materials shall conform to ASTM C 171, type optional, except that polyethylene film, if used, shall be white opaque.

16.1.2. Burlap. Burlap shall conform to AASHTO M 182.

16.1.3. White Pigmented Membrane-Forming Curing Compound White pigmented membrane-forming curing compound shall conform to ASTM C 309, Type 2.

16.1.4. Provide polyethylene sheeting that is at least 4 mils thick and free from visible defects. Provide only clear or opaque white sheeting when the ambient temperature during curing exceeds 60°F or when applicable to control temperature during mass pours.

16.1.5. Provide burlap-polyethylene mats made from burlap impregnated on 1 side with a film of opaque white pigmented polyethylene, free from visible defects. Provide laminated mats that have at least 1 layer of an impervious material such as polyethylene, vinyl plastic, or other acceptable material (either as a solid sheet or impregnated into another fabric) and are free of visible defects.

17. CONCRETE PROTECTION MATERIALS

Must meet commercial standards and the contractor shall notify of any exceptions. Concrete protection materials shall be a linseed oil mixture of equal parts, by volume, of linseed oil and either mineral spirits, naphtha, or turpentine. At the option of the Contractor, commercially prepared linseed oil mixtures, formulated specifically for application to concrete to provide protection against the action of deicing chemicals may be used, except that emulsified mixtures are not acceptable.

17.1. Expansion joint filler, premolded, shall conform to ASTM D 1751 or ASTM D 1752, 1/2 inch thick, unless otherwise indicated.

17.2. Joint Sealants, cold-applied shall conform to ASTM C 920 or ASTM D 5893.

Statement of Work. Rev. 11Aug15 Page 10 of 35

18. FORM WORK

18.1. Design and construct form work if used to ensure that the finished concrete will conform accurately to the indicated dimensions, lines, and elevations, and within the tolerances specified.

Forms shall be of wood or steel, straight, of sufficient strength to resist springing during depositing and consolidating concrete. Wood forms shall be surfaced plank, 2 inches nominal thickness, straight and free from warp, twist, loose knots, splits or other defects. Wood forms shall have a nominal length of 10 feet. Radius bends may be formed with 3/4 inch boards, laminated to the required thickness. Steel forms shall be channel-formed sections with a flat top surface and with welded braces at each end and at not less than two intermediate points. Ends of steel forms shall be interlocking and self-aligning. Steel forms shall include flexible forms for radius forming, corner forms, form spreaders, and fillers. Steel forms shall have a nominal length of 10 feet with a minimum of 3 welded stake pockets per form. Stake pins shall be solid steel rods with chamfered heads and pointed tips designed for use with steel forms.

18.1.1. Sidewalk Forms Sidewalk forms shall be of a height equal to the full depth of the finished sidewalk.

18.1.2. Curb and gutter outside forms shall have a height equal to the full depth of the curb or gutter. The inside form of curb shall have batter as indicated and shall be securely fastened to and supported by the outside form. Rigid forms shall be provided for curb returns, except that benders or thin plank forms may be used for curb or curb returns with a radius of 10 feet or more, where grade changes occur in the return, or where the central angle is such that a rigid form with a central angle of 90 degrees cannot be used. Back forms for curb returns may be made of 1-1/2 inch benders, for the full height of the curb, cleated together. In lieu of inside forms for curbs, a curb "mule" may be used for forming and finishing this surface, provided the results are approved if needed.

18.1.3. Conventionally Formed Concrete. Reusable forms shall be of metal or wood and shall extend for the full depth of the concrete. All forms shall be free from warp and of sufficient strength to resist the pressure of the concrete without displacement. Bracing and staking of forms shall be such that the forms remain in both horizontal and vertical alignment until their removal.

All forms shall be cleaned and coated with an approved form release agent or form oil before concrete is placed. Divider plates shall be of metal. Forms shall conform to the specified radius when placed on curves.

18.1.4. Extruded or Slip-Formed Concrete. A slip form paver approved by the Engineer shall lay the sidewalk. Contractor shall set guidelines or guide-rails from survey marks established by the Engineer. Guidelines shall be set to avoid obstacles in the path that may interfere with operation of equipment and overall quality of sidewalk. Sidewalk outline shall strictly conform to the details shown on the plans or as set by Engineer. Slip form equipment shall be operated according to machine specifications and manual for paving accuracy. Slip form equipment shall spread, consolidate and finish the concrete to produce a dense homogeneous concrete true to grade and cross section. Concrete shall be consolidated by the use of internal vibrators. The concrete shall be of such consistency that it will maintain the shape of the sidewalk section without support.

Statement of Work. Rev. 11Aug15 Page 11 of 35

18.2. EXECUTION

18.2.1. SUBGRADE PREPARATION

18.2.1.1. The subgrade shall be constructed to the specified grade and cross section prior to concrete placement. Subgrade shall be placed and compacted in conformance.

18.2.2. Sidewalk Subgrade. The subgrade shall be tested for grade and cross section with a template extending the full width of the sidewalk and supported between side forms.

18.2.3. Curb and Gutter Subgrade. The subgrade shall be tested for grade and cross section by means of a template extending the full width of the curb and gutter. The subgrade shall be of materials equal in bearing quality to the subgrade under the adjacent pavement.

18.2.4. Maintenance of Subgrade. The subgrade shall be maintained in a smooth, compacted condition in conformity with the required section and established grade until the concrete is placed.

The subgrade shall be in a moist condition when concrete is placed. The subgrade shall be prepared and protected to produce a subgrade free from frost when the concrete is deposited.

18.2.4.1. Form setting. Set forms to the indicated alignment, grade and dimensions. Hold forms rigidly in place by a minimum of 3 stakes per form placed at intervals not to exceed 4 feet.

Corners, deep sections, and radius bends shall have additional stakes and braces, as required.

Clamps, spreaders, and braces shall be used where required to ensure rigidity in the forms. Forms shall be removed without injuring the concrete. Bars or heavy tools shall not be used against the concrete in removing the forms. Any concrete found defective after form removal shall be promptly and satisfactorily repaired. Forms shall be cleaned and coated with form oil each time before concrete is placed. Wood forms may, instead, be thoroughly wetted with water before concrete is placed, except that with probable freezing temperatures, oiling is mandatory.

18.2.4.2. Sidewalks. Set forms for sidewalks with the upper edge true to line and grade with an allowable tolerance of 1/8 inch in any 10 foot long section. After forms are set, grade and alignment shall be checked with a 10 foot straightedge. Forms shall have a transverse slope of 1/4 inch per foot with the low side adjacent to the roadway. Side forms shall not be removed for 12 hours after finishing has been completed.

18.2.4.3. Curbs and Gutters. The forms of the front of the curb shall be removed not less than 2 hours nor more than 6 hours after the concrete has been placed. Forms back of curb shall remain in place until the face and top of the curb have been finished, as specified for concrete finishing.

Gutter forms shall not be removed while the concrete is sufficiently plastic to slump in any direction.

18.3. SIDEWALK CONCRETE PLACEMENT AND FINISHING

18.3.1. Formed Sidewalks. Place concrete in the forms in one layer. When consolidated and finished, the sidewalks shall be of the thickness indicated (refer to Appendix C). After concrete has been placed in the forms, a strike-off guided by side forms shall be used to bring the surface to

Statement of Work. Rev. 11Aug15 Page 12 of 35 proper section to be compacted. The concrete shall be consolidated with an approved vibrator, and the surface shall be finished to grade with a strike off.

18.3.2. Edge and Joint Finishing. All slab edges, including those at formed joints, shall be finished with an edger having a radius of 1/8 inch. Transverse joint shall be edged before brooming, and the brooming shall eliminate the flat surface left by the surface face of the edger. Corners and edges which have crumbled and areas which lack sufficient mortar for proper finishing shall be cleaned and filled solidly with a properly proportioned mortar mixture and then finished.

18.3.3. Surface and Thickness Tolerances. Finished surfaces shall not vary more than 5/16 inch from the testing edge of a 10-foot straightedge. Permissible deficiency in section thickness will be up to 1/4 inch.

18.4. CURB AND GUTTER CONCRETE

18.4.1. Formed Curb and Gutter. Concrete shall be placed to the section required in a single lift.

Consolidation shall be achieved by using approved mechanical vibrators. Curve shaped gutters shall be finished with a standard curb.

18.4.2. Curb and Gutter Finishing. Approved slipformed curb and gutter machines may be used in lieu of hand placement.

18.4.3. Concrete Finishing. Exposed surfaces shall be floated and finished with a smooth wood float until true to grade and section and uniform in texture. Floated surfaces shall then be brushed with a fine-hair brush with longitudinal strokes. The edges of the gutter and top of the curb shall be rounded with an edging tool to a radius of 1/2 inch. Immediately after removing the front curb form, the face of the curb shall be rubbed with a wood or concrete rubbing block and water until blemishes, form marks, and tool marks have been removed. The front curb surface, while still wet, shall be brushed in the same manner as the gutter and curb top. The top surface of gutter and entrance shall be finished to grade with a wood float. Concrete curb and gutters shall receive a “non-slip” finish.

After straight-edging, when most of the water sheen has disappeared, and just before the concrete hardens, finish the surface with a wood float or darby to a smooth and uniformly fine granular or sandy texture free of waves, irregularities, or tool marks. A scored surface by brooming with a fiber-bristle brush in a direction transverse to that of the traffic, followed by edging. Concrete sidewalks shall have a “non-slip” finish.

18.4.4. Joint Finishing. Curb edges at formed joints shall be finished as indicated.

18.4.5. Surface and Thickness Tolerances. Finished surfaces shall not vary more than 1/4 inch from the testing edge of a 10-foot straightedge. Permissible deficiency in section thickness will be up to 1/4 inch.

18.5. SIDEWALK JOINTS

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18.5.1. Sidewalk joints shall be constructed to divide the surface into rectangular areas.

Transverse contraction joints shall be spaced at a distance equal to the sidewalk width or 5 feet on centers, whichever is less, and shall be continuous across the slab. Transverse expansion joints shall be installed at sidewalk returns and opposite expansion joints in adjoining curbs. Where the sidewalk is not in contact with the curb, transverse expansion joints shall be installed as indicated.

Expansion joints shall be formed about structures and features which project through or into the sidewalk pavement, using joint filler of the type, thickness, and width indicated.

18.5.2. Sidewalk Contraction Joints. The contraction joints shall be formed in the fresh concrete by cutting a groove in the top portion of the slab to a depth of at least one-fourth of the sidewalk slab thickness, using a jointer to cut the groove, or by sawing a groove in the hardened concrete with a power-driven saw, unless otherwise approved. Sawed joints shall be constructed by sawing a groove in the concrete with a 1/8 inch blade to the depth indicated. An ample supply of saw blades shall be available on the job before concrete placement is started, and at least one standby sawing unit in good working order shall be available at the jobsite at all times during the sawing operations.

18.5.3. Sidewalk Expansion Joints. Expansion joints shall be formed with 1/2 inch joint filler strips. Joint filler in expansion joints surrounding structures and features within the sidewalk may consist of preformed filler material conforming to ASTM D 1752 or building paper. Joint filler shall be held in place with steel pins or other devices to prevent warping of the filler during floating and finishing. Immediately after finishing operations are completed, joint edges shall be rounded with an edging tool having a radius of 1/8 inch, and concrete over the joint filler shall be removed. At the end of the curing period, expansion joints shall be cleaned and filled with cold-applied joint sealant. Joint sealant shall be gray or stone in color. Joints shall be sealed as specified in Section 32 01 19 FIELD MOLDED SEALANTS FOR SEALING JOINTS IN RIGID PAVEMENTS. Sidewalk expansion joints shall be no more than 40’-0” on center.

18.5.4. Reinforcement Steel Placement. Reinforcement steel shall be accurately and securely fastened in place with suitable supports and ties before the concrete is placed.

18.5.5. Curb and Gutters. Curb and gutter joints shall be constructed at right angles to the line of curb and gutter.

18.5.6. Contraction Joints. Contraction joints shall be constructed directly opposite contraction joints in abutting portland cement concrete pavements and spaced so that monolithic sections between curb returns will not be less than 5 feet nor greater than 15 feet in length.

a. Contraction joints (except for slip forming) shall be constructed by means of 1/8 inch thick separators and of a section conforming to the cross section of the curb and gutter. Separators shall be removed as soon as practicable after concrete has set sufficiently to preserve the width and shape of the joint and prior to finishing.

b. When slip forming is used, the contraction joints shall be cut in the top portion of the gutter/curb hardened concrete in a continuous cut across the curb and gutter, using a power-driven saw. The depth of cut shall be at least one-fourth of the gutter/curb depth and 1/8 inch in width.

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18.5.7. Expansion Joints. Expansion joints shall be formed by means of preformed expansion joint filler material cut and shaped to the cross section of curb and gutter. Expansion joints shall be provided in curb and gutter directly opposite expansion joints of abutting portland cement concrete pavement, and shall be of the same type and thickness as joints in the pavement. Where curb and gutter do not abut portland cement concrete pavement, expansion joints at least 1/2 inch in width shall be provided at intervals not less than 30 feet nor greater than 40’feet. Expansion joints shall be provided in nonreinforced concrete gutter at locations indicated.

Expansion joints shall be sealed immediately following curing of the concrete or as soon thereafter as weather conditions permit. Joints shall be sealed as specified in Section 32 01 19 FIELD MOLDED SEALANTS FOR SEALING JOINTS IN RIGID PAVEMENTS. Expansion joints and the top 1 inch depth of curb and gutter contraction-joints shall be sealed with joint sealant. The joint opening shall be thoroughly cleaned before the sealing material is placed. Sealing material shall not be spilled on exposed surfaces of the concrete. Concrete at the joint shall be surface dry and atmospheric and concrete temperatures shall be above 50 degrees F at the time of application of joint sealing material. Excess material on exposed surfaces of the concrete shall be removed immediately and concrete surfaces cleaned.

18.6. CURING AND PROTECTION

18.6.1. General Requirements. Protect concrete against loss of moisture and rapid temperature changes for at least 7 days from the beginning of the curing operation. Protect unhardened concrete from rain and flowing water. All equipment needed for adequate curing and protection of the concrete shall be on hand and ready for use before actual concrete placement begins.

Protection shall be provided as necessary to prevent cracking of the pavement due to temperature changes during the curing period.

18.6.2. Mat Method for After Concrete Pour. The entire exposed surface shall be covered with 2 or more layers of burlap. Mats shall overlap each other at least 6 inches. The mat shall be thoroughly wetted with water prior to placing on concrete surface and shall be kept continuously in a saturated condition and in intimate contact with concrete for not less than 7 days.

18.6.3. Impervious Sheeting Method. The entire exposed surface shall be wetted with a fine spray of water and then covered with impervious sheeting material. Sheets shall be laid directly on the concrete surface with the light-colored side up and overlapped 12 inches when a continuous sheet is not used. The curing medium shall not be less than 18-inches wider than the concrete surface to be cured, and shall be securely weighted down by heavy wood planks, or a bank of moist earth placed along edges and laps in the sheets. Sheets shall be satisfactorily repaired or replaced if torn or otherwise damaged during curing. The curing medium shall remain on the concrete surface to be cured for not less than 7 days.

18.6.4. Membrane Curing Method. Curing and backfilling operation shall be completed prior to applying two coats of protective coating. Concrete shall be surface dried and cleaned before each application. Coverage shall be by spray application at not more than 50 square yards/gallon for first application and not more than 70 square yards/gallon for second application, except that the number of applications and coverage for each application for commercially prepared mixture shall

Statement of Work. Rev. 11Aug15 Page 15 of 35 be in accordance with the manufacturer's instructions. Coated surfaces shall be protected from vehicular and pedestrian traffic until dry.

A uniform coating of white-pigmented membrane-curing compound shall be applied to the entire exposed surface of the concrete as soon after finishing as the free water has disappeared from the finished surface. Formed surfaces shall be coated immediately after the forms are removed and in no case longer than 1 hour after the removal of forms. Concrete shall not be allowed to dry before the application of the membrane. If any drying has occurred, the surface of the concrete shall be moistened with a fine spray of water and the curing compound applied as soon as the free water disappears. Curing compound shall be applied in two coats by hand-operated pressure sprayers at a coverage of approximately 200 square feet/gallon for the total of both coats. The second coat shall be applied in a direction approximately at right angles to the direction of application of the first coat. The compound shall form a uniform, continuous, coherent film that will not check, crack, or peel and shall be free from pinholes or other imperfections. If pinholes, abrasion, or other discontinuities exist, an additional coat shall be applied to the affected areas within 30 minutes.

Concrete surfaces that are subjected to heavy rainfall within 3 hours after the curing compound has been applied shall be resprayed by the method and at the coverage specified above. Areas where the curing compound is damaged by subsequent construction operations within the curing period shall be resprayed. Necessary precautions shall be taken to insure that the concrete is properly cured at sawed joints, and that no curing compound enters the joints. The top of the joint opening and the joint groove at exposed edges shall be tightly sealed before the concrete in the region of the joint is resprayed with curing compound. The method used for sealing the joint groove shall prevent loss of moisture from the joint during the entire specified curing period. Approved standby facilities for curing concrete pavement shall be provided at a location accessible to the jobsite for use in the event of mechanical failure of the spraying equipment or other conditions that might prevent correct application of the membrane-curing compound at the proper time. Concrete surfaces to which membrane-curing compounds have been applied shall be adequately protected during the entire curing period from pedestrian and vehicular traffic, except as required for joint-sawing operations and surface tests, and from any other possible damage to the continuity of the membrane.

18.6.5. Backfilling. After curing, debris shall be removed and the area adjoining the concrete shall be backfilled, graded, and compacted to conform to the surrounding area in accordance with lines and grades indicated.

18.6.6. Protection. Completed concrete shall be protected from damage until accepted. Repair damaged concrete and clean concrete discolored during construction. Concrete that is damaged shall be removed and reconstructed for the entire length between regularly scheduled joints.

Refinishing the damaged portion will not be acceptable. Removed damaged portions shall be disposed of as directed.

18.6.7. Protective Coating. Protective coating, of linseed oil mixture, shall be applied to the exposed-to-view concrete surface after the curing period, if concrete will be exposed to de-icing chemicals within 6 weeks after placement. Concrete to receive a protective coating shall be moist cured.

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18.6.8. Application. Curing and backfilling operation shall be completed prior to applying two coats of protective coating. Concrete shall be surface dry and clean before each application.

Coverage shall be by spray application at not more than 50 square yards/gallon for first application and not more than 70 square yards/gallon for second application, except that the number of applications and coverage for each application for commercially prepared mixture shall be in accordance with the manufacturer's instructions. Coated surfaces shall be protected from vehicular and pedestrian traffic until dry.

18.6.9. Precautions. Protective coating shall not be heated by direct application of flame or electrical heaters and shall be protected from exposure to open flame, sparks, and fire adjacent to open containers or applicators. Material shall not be applied at ambient or material temperatures lower than 50 degrees F.

18.7. FIELD QUALITY CONTROL

18.7.1. General Requirements. Perform the inspection and tests described and meet the specified requirements for inspection details and frequency of testing. Based upon the results of these inspections and tests, take the action and submit reports as required below, and any additional tests to insure that the requirements of these specifications are met.

18.7.2. Concrete Testing

18.7.2.1. Strength Testing. Provide molded concrete specimens for strength tests. Samples of concrete placed each day shall be taken not less than once a day nor less than once for every 250 cubic yards of concrete. The samples for strength tests shall be taken in accordance with ASTM C

172. Cylinders for acceptance shall be molded in conformance with ASTM C 31 by an approved testing laboratory. Each strength test result shall be the average of 2 test cylinders from the same concrete sample tested at 28 days, unless otherwise specified or approved. Concrete specified on the basis of compressive strength will be considered satisfactory if the averages of all sets of three consecutive strength test results equal or exceed the specified strength, and no individual strength test result falls below the specified strength by more than 1500 psi.

18.7.2.2. Air Content. Determine air content in accordance with ASTM C 173 or ASTM C 231.

ASTM C 231 shall be used with concretes and mortars made with relatively dense natural aggregates. Two tests for air content shall be made on randomly selected batches of each class of concrete placed during each shift. Additional tests shall be made when excessive variation in concrete workability is reported by the placing foreman or the Government inspector. If results are out of tolerance, the placing foreman shall be notified and he shall take appropriate action to have the air content corrected at the plant. Additional tests for air content will be performed on each truckload of material until such time as the air content is within the tolerance specified.

18.7.3. Slump Test. Two slump tests shall be made on randomly selected batches of each class of concrete for every 250 cubic yards, or fraction thereof, of concrete placed during each shift.

Additional tests shall be performed when excessive variation in the workability of the concrete is noted or when excessive crumbling or slumping is noted along the edges of slip-formed concrete.

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18.7.4. Thickness Evaluation. The anticipated thickness of the concrete shall be determined prior to placement by passing a template through the formed section or by measuring the depth of opening of the extrusion template of the curb forming machine.