B08_-_PWS_-_Alamosa_Parking_Pad.pdf

Performance Work Statement

ADA Parking Pad & Walkway

Alamosa National Wildlife Refuge - Alamosa, Colorado

1.0 Introduction and Overview

The Alamosa National Wildlife Refuge covers 11,169 acres of high desert uplands and riparian wetlands in the San Luis Valley. It’s situated in a high-elevation, alpine basin in south-central Colorado. Residing at 7,800 feet above sea level, the valley covers more than 100 miles north to south and 50 miles east to west was established in July 1971.

Although mostly flat, some of the most majestic mountain ranges in the Rockies surrounded it.

The Sangre de Cristo lies the east, to the west are the San Juan Mountains, and the Sawatch sit north.

Thanks to the snow-capped peaks, the valley is able to sustain wildlife through surface ponds and rivers, and a large underground aquifer.

The refuge was founded to protect the food, cover, and breeding grounds for local wildlife and transient birds. It accomplishes that goal for more than 200 species of birds and other animals. Twice per year, around mid-March and mid-October, tens of thousands of Sandhill Cranes migrate through the San Luis Valley.

1.1 Scope of Work

The contractor shall construct a 432 square foot reinforced concrete pad / walkway that will serve as an ADA parking pad and walkway for a future Kiosk. The pad shall be 5,000 psi reinforced concrete with #3 rebar 12” O.C. and have a 23.5” thickened edge. The slab shall have a max slope of 2% to prevent ponding of water on the slab. Refer to drawings for pad dimensions configuration.

1.2 Period of Performance

The work shall be completed in 60 days from notice to proceed. It is the government’s desire to have this slab poured before the first frost of 2023.

1.3 Project Safety

The Contractor shall be responsible for strict compliance with all provisions of Occupational Safety and Health Administration (OSHA) requirements 29 CFR 1910 and 29CFR 1926 during performance of the work.

2.0 Project Requirements

A. All work will adhere to local building codes. All work and materials shall be in compliance with all applicable building codes, and the applicable performance standards:

1. American Society for Testing Materials (ASTM)

2. International Building Code (IBC).

https://www.uncovercolorado.com/activities/sangre-de-cristo-mountain-range/ https://www.uncovercolorado.com/san-luis-valley-colorado/ https://www.uncovercolorado.com/san-luis-valley-colorado/

B. Field Measurements:

On site field investigation and measurements shall be made prior to construction.

3.0 Material Submittals

A. Material submittals consisting of material and manufacturer's product information shall be provided to Contracting Officer Representative (COR) for approval prior to any materials are purchased on this project.

4.0 End Results/Deliverables

A. Pour 432 square foot 5,000 psi reinforced concrete slab and construct a (3) panel kiosk per drawing.

B. Upon completion of the project, all work areas shall be free of rubbish and debris.

5.0 Special considerations

1. Technical / government liaison for this contract is the USFWS Facilities Manager, Suzanne Beauchaine located at the HQ building, 719-588-3473. Normal working hours for Facility Staff are from 7:00 AM to 3:30 PM Monday through Friday except for Government holidays and special events.

2. Contractor allowable work hours are 7AM to 6:00 PM Monday through Friday. Weekend work is acceptable with prior arrangements with onsite staff from 8:00 am to 6:00 pm.

3. Water and power are not available for the contractor to use during the project. Contractor will need to provide their own power and water.

4. Restroom facilities (Vault Toilets) are available onsite for the contractor to use during the project.

5. Onsite parking is available at the jobsite for the contractor to use during the project.

6. Laydown and Washout area is available onsite and will be coordinated between refuge staff and the contractor.

7. Framing and Slab must be protected from visitors while construction and concrete curing.

6.0 Specifications

033000 CAST IN PLACE CONCRETE

Part 1 - GENERAL

1.1 SUMMARY

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

B. Related Sections:

1. Section 072600 "Vapor Retarders" for sheet vapor retarders under slabs-on-grade.

2. Section 313215 "Excavation, Fill and Compaction" for materials beneath slabs-on-grade.

1.2 ACTION SUBMITTALS

A. Product Data: For each type of product indicated.

B. Design Mixtures: For each concrete mixture.

C. Test reports required per Testing Schedule.

1.3 INFORMATIONAL SUBMITTALS

A. Material certificates.

B. Material test reports.

C. Silica Dust reduction, prevention and protection plan for saw cutting concrete.

1.4 QUALITY ASSURANCE

A. 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.

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

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

1. ACI 301, "Specifications for Structural Concrete,"

2. ACI 318, “Building Code Requirements for Reinforced Concrete”

3. ACI 350 “Environmental Engineering Concrete”

4. ACI 117, "Specifications for Tolerances for Concrete Construction and Materials."

D. Concrete Testing Service: Engage a qualified independent testing agency to perform material evaluation tests.

E. Silica Dust Protection: Provide a plan to reduce silica dust production and protect personnel from silica dust inhalation. Plan provided shall be per OSHA recommendations and training shall be provided on site prior to work commencing. Proper personal protection equipment shall be provided and used while working on the site.

Part 2 - PRODUCTS

2.1 FORM-FACING MATERIALS

A. Smooth-Formed Finished Concrete: Form-facing panels that will provide continuous, true, and smooth concrete surfaces. Furnish in largest practicable sizes to minimize number of joints.

B. Rough-Formed Finished Concrete: Plywood, lumber, metal, or another approved material.

Provide lumber dressed on at least two edges and one side for tight fit.

2.2 STEEL REINFORCEMENT

A. Reinforcing Bars: ASTM A 615/A 615M, Grade 60, deformed.

B. Plain-Steel Welded Wire Reinforcement (WWR): ASTM A 185/A 185M, plain, fabricated from as-drawn steel wire into flat sheets.

C. Deformed-Steel Welded Wire Reinforcement (WWR): ASTM A 497/A 497M, flat sheet.

D. 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.

2.3 CONCRETE MATERIALS

A. General

1. Materials shall be classified as acceptable for potable water use according to NSF Standard 61.

2. Cement for Concrete that will contact potable water shall not be obtained from kilns that burn metal rich hazardous waste fuel.

3. Materials shall be delivered, stored, and handled so as to prevent damage by water or breakage. Cement reclaimed from cleaning bags or leaking containers shall not be used.

Cement shall be used in the sequence of receipt of shipments.

B. Materials and storage of materials shall comply with ACI 301, as applicable.

C. Cementitious Material: Use the following cementitious materials, of the same type, brand, and source, throughout Project:

1. Portland Cement: ASTM C 150, Type I/II or Type II. Supplement with the following:

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

D. Normal-Weight Aggregates: ASTM C 33, graded.

1. Maximum Coarse-Aggregate Size: Crushed stone or gravel, ASTM C33 (1) inch nominal.

2. Fine Aggregate: Natural sand ASTM 33, free of materials with deleterious reactivity to alkali in cement. Fineness modulus shall not be less than 2.5 nor more than 3.0

E. Water: ASTM C 94/C 94M.

2.4 ADMIXTURES

A. Air-Entraining Admixture: ASTM C 260.

B. Chemical Admixtures: Provide admixtures certified by manufacturer to be compatible with other admixtures and that will 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.

2.5 VAPOR RETARDERS

A. Sheet Vapor Retarder: Sheet vapor retarder for use under slabs on grade are specified in Section 072600 “Vapor Retarders”

2.6 WATERSTOPS

A. Flexible PVC Waterstops: CE CRD-C 572 for embedding in concrete to prevent passage of fluids through joints. Factory fabricate corners, intersections, and directional changes.

2.7 CURING MATERIALS

A. Evaporation Retarder: Waterborne, monomolecular film forming, manufactured for application to fresh concrete.

B. Absorptive Cover: AASHTO M 182, Class 2, burlap cloth made from jute or kenaf, weighing approximately 9 oz./sq. yd. when dry.

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

D. Water: Potable.

E. Clear, Waterborne, Membrane-Forming Curing Compound: ASTM C 309, Type 1, Class B, dissipating.

2.8 RELATED MATERIALS

A. Expansion- and Isolation-Joint-Filler Strips:

1. Exterior: ASTM D 994, bituminous strip, minimum 1/2-inch thick, height equal to joint depth.

2. Interior: ASTM D 1752, sponge rubber, concrete gray in color, minimum 1/2-inch thick, height equal to joint depth.

B. Sleeves: PVC-Pipe Sleeves: ASTM D 1785, Schedule 40 with water stop collar at midpoint of sleeve. Size as needed.

2.9 CONCRETE MIXTURES

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, ground granulated blast-furnace slag, and silica fume as needed to reduce the total amount of portland cement, which would otherwise be used, by not less than 20 percent by weight.

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.

3. Use water-reducing admixture in

a. Pumped concrete.

b. Concrete for heavy-use industrial slabs and parking structure slabs.

c. Concrete required to be watertight.

d. Concrete with a water-cementitious materials ratio below 0.50.

D. Proportion normal-weight concrete mixture used for Exterior Concrete slabs, pads, and walkways as follows:

1. Minimum Compressive Strength: 5000 psi at 28 days.

2. Maximum Water-Cementitious Materials Ratio: 0.49.

3. Slump Limit: 5 inches plus or minus 1 inch.

4. Air Content: 3 percent, plus or minus 1 percent.

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 (30 and 32 deg C), reduce mixing and delivery time from 1-1/2 hours to 75 minutes; when air temperature is above 90 deg F (32 deg C), reduce mixing and delivery time to 60 minutes.

Part 3 - EXECUTION

3.1 FORMWORK

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.

1. Chamfer Size: 3/4 inch.

3.2 EMBEDDED ITEMS

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.

3.3 VAPOR RETARDERS

A. Sheet Vapor Retarders: Place, protect, and repair sheet vapor retarder according to ASTM E 1643 and manufacturer's written instructions.

3.4 STEEL REINFORCEMENT

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

1. Do not cut or puncture vapor retarder. Repair damage and reseal vapor retarder before placing concrete.

3.5 JOINTS

A. General: Construct joints true to line with faces perpendicular to surface plane of concrete.

B. Construction Joints: Install so strength and appearance of concrete are not impaired, at locations indicated or as approved by Architect.

C. Contraction Joints in Slabs-on-Grade: Form weakened-plane contraction joints, sectioning concrete into areas as indicated. Construct contraction joints for a depth equal to at least 1/4 of concrete thickness as follows:

1. Grooved Joints: Form contraction joints after initial floating by grooving and finishing each edge of joint to a radius of 1/8 inch. Repeat grooving of contraction joints after applying surface finishes. Eliminate groover tool marks on concrete surfaces.

2. Sawed Joints: Form contraction joints with power saws equipped with shatterproof abrasive or diamond-rimmed blades. Cut 1/8-inch wide joints into concrete when cutting action will not tear, abrade, or otherwise damage surface and before concrete develops random contraction cracks.

D. Isolation Joints in Slabs-on-Grade: After removing formwork, install joint-filler strips at slab junctions with vertical surfaces, such as column pedestals, foundation walls, grade beams, and other locations, as indicated.

3.6 CONCRETE PLACEMENT

A. Before placing concrete, verify that installation of formwork, reinforcement, and embedded items is complete and that required inspections have been performed.

B. Deposit concrete continuously in one layer or in horizontal layers of such thickness that no new concrete will be 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.

C. Cold-Weather Placement: Comply with ACI 306.1.

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

3.7 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.

1. Apply to concrete surfaces below finish grade adjacent to back fill, fill, gravel, or pavement.

B. Smooth-Formed Finish: As-cast concrete texture imparted by form-facing material, arranged in an orderly and symmetrical manner with a minimum of seams. Repair and patch tie holes and defects. Remove fins and other projections that exceed specified limits on formed-surface irregularities.

1. Apply to concrete surfaces exposed to public view, to receive a rubbed finish, surfaces exposed to elements, and surfaces to be covered with a coating or covering material applied directly to concrete.

C. Rubbed Finish: Apply the following to smooth-formed finished as-cast concrete where indicated:

1. Smooth-Rubbed Finish: Not later than one day after form removal, moisten concrete surfaces and rub with carborundum brick or another abrasive until producing a uniform color and texture. Do not apply cement grout other than that created by the rubbing process.

2. Grout-Cleaned Finish: Wet concrete surfaces and apply grout of a consistency of thick paint to coat surfaces and fill small holes. Mix one part portland cement to one and one-half parts fine sand with a 1:1 mixture of bonding admixture and water. Add white portland cement in amounts determined by trial patches so color of dry grout will match adjacent surfaces. Scrub grout into voids and remove excess grout. When grout whitens, rub surface with clean burlap and keep surface damp by fog spray for at least 36 hours.

3. Cork-Floated Finish: Wet concrete surfaces and apply a stiff grout. Mix one part portland cement and one part fine sand with a 1:1 mixture of bonding agent and water. Add white portland cement in amounts determined by trial patches so color of dry grout will match adjacent surfaces. Compress grout into voids by grinding surface. In a swirling motion, finish surface with a cork float.

D. Related Unformed Surfaces: At tops of walls, horizontal offsets, and similar unformed surfaces adjacent to formed surfaces, strike off smooth and finish with a texture matching adjacent formed surfaces. Continue final surface treatment of formed surfaces uniformly across adjacent unformed surfaces unless otherwise indicated.

3.8 FINISHING FLOORS AND SLABS

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

B. Trowel Finish: After applying float finish, apply first troweling and consolidate concrete by hand or power-driven trowel. Continue troweling passes and restraighten until surface is free of trowel marks and uniform in texture and appearance. Grind smooth any surface defects that would telegraph through applied coatings or floor coverings.

1. Apply a trowel finish to surfaces interior monolithic slabs.

2. Finish and measure surface so gap at any point between concrete surface and an unleveled, freestanding, 10-ft. long straightedge resting on two high spots and placed anywhere on the surface does not exceed 1/8 inch.

C. Trowel and Fine-Broom Finish: Apply a first trowel finish to non-water and water bearing slabs. While concrete is still plastic, slightly scarify surface with a fine broom. Brooming shall be perpendicular to drainage unless otherwise indicated.

D. Broom Finish: Apply a broom finish to exterior concrete platforms, steps, ramps, and elsewhere as indicated.

3.9 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. Evaporation Retarder: Apply evaporation retarder to unformed concrete surfaces if hot, dry, or windy conditions cause moisture loss approaching 0.2 lb/sq. ft. x h before and during finishing operations. Apply according to manufacturer's written instructions after placing, screeding, and bull floating or darbying concrete, but before float finishing.

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 unless manufacturer certifies curing compound will not interfere with bonding of floor covering used on Project.

4. Curing and Sealing Compound: Apply uniformly to floors and slabs indicated in a 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. Repeat process 24 hours later and apply a second coat. Maintain continuity of coating and repair damage during curing period.

3.10 TREATMENT OF SURFACE DEFECTS

A. As soon as forms are removed, exposed surfaces shall be carefully examined and any irregularities shall be immediately rubbed or ground in a satisfactory manner in order to secure a smooth, uniform, and continuous surface. Concrete containing minor voids, holes, honeycombing, or similar depression defects shall be repaired.

B. Holes left by tie-rod cones shall be reamed with suitable toothed reamers so as to leave the surfaces of the holes clean and rough. Holes then shall be repaired in an approved manner with dry-packed cement grout.

C. Prior to filling any structure with water, cracks shall be "vee'd" as indicated and filled with sealant. This repair method shall be done on the water bearing face of members. Prior to backfilling, faces of members in contact with fill which are not covered with a waterproofing membrane shall also have cracks repaired as indicated herein.

3.11 CONCRETE SURFACE REPAIRS

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

3.12 CARE AND REPAIR OF CONCRETE

A. The Contractor shall protect concrete against injury or damage from excessive heat, lack of moisture, overstress, or any other cause until final acceptance. Particular care shall be taken to prevent the drying of concrete and to avoid roughening or otherwise damaging the surface.

3.13 FIELD QUALITY CONTROL

A. Testing and Inspecting: Contractor will engage a qualified testing and inspecting agency to perform field tests and inspections and prepare test reports.

B. Testing Schedule

1. Air Content: Per ASTM C 231. Test first load of concrete placed, and at each time test cylinders are cast.

2. Temperature: At each time air content is measured.

3. Slump Test: Per ASTM C 143.

a. First load of concrete placed each day.

b. On each load to which water is added to the mix at the job site.

c. On each load from which test cylinders are cast

d. The Contracting Officer reserves the right to perform (require) additional slump tests at any time.

4. Test Cylinders: Per ASTM C 31.

a. Provide one set of test cylinders for each 25 cubic yards of each class of concrete placed each day, with a minimum of one set of test cylinders made for each day concrete is placed. Each set of test cylinders shall consist of four cylinders. At least two cylinders shall be cast from the first load of concrete placed each day.

b. No sooner than 24 hours after taking cylinders, carefully transport cylinders to testing laboratory for moisture curing. Test cylinders shall be made in the presence of an authorized representative of the Contracting Officer.

c. Identify all test cylinders with symbols to indicate placement locations on the job represented by the test cylinders, and note on record drawings.

5. Compression Tests:

a. One cylinder to failure at 7 days.

b. Two cylinders to failure at 28 days. The 28 day result shall be an average of the two.

c. Remaining cylinder may be broken at Contractor’s request or the Contracting Officer’s discretion at:

1) Less than 7 days for consideration of form removal.

2) 14 days to evaluate rate of strength gain.

3) 7 or 28 days to confirm other breaks.

4) 45 days if 28 day breaks are below specified strength.

d. Should the last cylinder not be needed for any of the above purposes, it may be discarded.

E. Water: ASTM C 94/C 94M.

B. Sleeves: PVC-Pipe Sleeves: ASTM D 1785, Schedule 40 with water stop collar at midpoint of sleeve. Size as needed.

D. Isolation Joints in Slabs-on-Grade: After removing formwork, install joint-filler strips at slab junctions with vertical surfaces, such as column pedestals, foundation walls, grade beams, and other locations, as indicated.

D. Related Unformed Surfaces: At tops of walls, horizontal offsets, and similar unformed surfaces adjacent to formed surfaces, strike off smooth and finish with a texture matching adjacent formed surfaces. Continue final surface treatment of formed su...

4. Curing and Sealing Compound: Apply uniformly to floors and slabs indicated in a continuous operation by power spray or roller according to manufacturer's written instructions. Recoat areas subjected to heavy rainfall within three hours after initia...

d. Should the last cylinder not be needed for any of the above purposes, it may be discarded.