J.1 Bird_Creek_Shade_Pavilion_Minimum_Specifications.pdf

BIRD CREEK CAMPGROUND SHADE PAVILION 2023

Contents Section 010100 – Summary of Work

010100 Part 2 -GSA SCHEDULE REQUIRED IFORMATION TABLE

Section 033015 – concrete for minor structures

Section 022220 – STRUCTURAL EXCAVATION, BACKFILL, AND COMPACTION

Solicitation No.: 1240LT23Q0089 J.1 Attachment

USDA FOREST SERVICE, R-4

Bird Creek Shade Pre-Engineered Shade Pavilion

SECTION 010100 – SUMMARY OF WORK

PART 1 - GENERAL

1.1 SUMMARY

A. Work for this project consists of provision and installation of a an approximately 1600sf pre-engineered shade structure including all excavation and concrete. Vendor shall be responsible for all structural design details of building and footings, but shall minimally meet the requirements set forth in Sections 033015 an 022220 of this document. This is to ensure reinforced concrete, formwork, aggregate, compaction, subgrade, and backfill are addressed and to a standard equal to or better than the government requires.

1.2 LOCATION

A. This project is located in Bird Creek Campground, Ely Ranger District, located approximately 33 miles north-east of Ely, NV.

1.3 GENERAL SITE CONDITIONS AND WEATHER

A. The elevation of the site is approximately 7500 feet above mean sea level. The construction site experiences heavy snowfall and extremely cold temperatures, with snow on the ground typically from mid-September through May.

B. In-depth soil surveys have not been performed; however, rocks at the ground surface are evident throughout the area. The Contractor should expect to encounter such rock during excavation and grubbing operations. Blasting of rocks will not be permitted without special permission.

C. In-depth water table surveys have not been performed; however, if water is encountered during excavation, the Contractor shall perform adequate dewatering to keep the excavation free from water and dispose of the water without damage to property.

1.4 USE OF PREMISES

A. General: Contractor shall have full use of the parking area for the group site for construction operations, including use of Project site, during construction period.

Contractor's use of premises is limited only by the Government's right to perform work or to retain other contractors on portions of Project. The rest of the campground will remain open during the construction period.

B. Contractor shall at all times conduct operations to ensure the least inconvenience to the public and employees. Partial closure of the effected end of the campground loop closures will be permitted, when required, upon written approval of the Contracting Officer (CO).

Solicitation No.: 1240LT23Q0089

C. Confine storage of materials to areas as approved by the CO.

D. Contractor shall provide adequate signing and barricades and take necessary safety measures to protect the public during all construction operations. Contractor shall minimize disturbance of all undisturbed areas.

E. Preservation of Natural Features: Confines all operations to work limits of the project.

Prevent damage to natural surroundings. Restore damaged areas, repairing or replacing damaged trees and plants, at no additional expense to the Government.

1. Provide temporary barriers to protect existing trees and plants and root zones.

2. Do not remove, injure, or destroy trees or other plants without prior approval.

Consult with CO and remove agreed-on roots and branches that interfere with construction.

3. Do not fasten ropes, cables, or guys to existing trees.

4. Carefully supervise excavating, grading, filling, and other construction operations near trees to prevent damage.

F. Existing Utilities: Notify CO and utility companies of proposed locations and times for excavation.

1. Contractor shall be responsible for locating and preventing damage to known utilities. If damage occurs, repair utility at no additional expense to the Government.

2. Interruption of Existing Utility Service: Notify CO, 48 hours in advance of any interruption of existing utilities.

1.5 MEALS AND LODGING

A. Meals and lodging are commercially available in the town of Ely, NV within 35 miles of the construction site. Meals or lodging will not be available at Forest Service facilities.

1.6 CAMPING

A. With approval by the ELY Ranger District, National Forest Service lands may be used by the Contractor to have one fully contained recreation vehicle which may remain at this site for security.

1.7 CONSTRUCTION SEQUENCE

A. There is no specified construction sequence or season for this project.

B. Depending on conditions, normal fire restrictions may apply to activities associated with this project.

1.8 FIELD VERIFICATION

A. Field verify all new and existing dimensions affecting the work of this contract before ordering products.

Solicitation No.: 1240LT23Q0089

1.9 PERMITS

A. Special permits for electrical work or any other permits required by County, State, or Federal laws or regulations shall be obtained by the Contractor.

1.10 SUBMITTIALS

A. In addition to those submittals shown in the drawings, the contractor shall submit a proposed construction schedule.

010100 PART 2 -GSA SCHEDULE REQUIRED IFORMATION TABLE

TABLE 2.1

Location: Ely NV Coordinates from Google Earth:

39°27’45”N 114°39’4”W

Elevation 7470 ft Other information: 33 Miles from Ely, NV

Construction

Powder-coated Steel Structural Framing, reinforced concrete footings (Optional item, weath-ered steel rather than powder-coat)

Roof Standing Seam Metal

Profile Type Two slopes with central ridge.

Building Width 40’0” ±2’

Ridge Location Center Ridge to run north and south (See drawing schematic)

Left Roof Slope Range May Range from 4:12 to 6:12 Left Actual Eave Ht. 8' 8" ±1’

Building Length 40' 0" ±2’ Ridge Height 17’0” ±2’ Right Roof Slope 5.000:12 Right Actual Eave Ht. 8’8” ±1’

Color

Offeror shall submit color rec-ommendations to best compli-ment existing structures (See attached photo)

Solicitation No.: 1240LT23Q0089

PART 2 - EXECUTION (Not Used)

END OF SECTION 010100

August 2023

LOADS

Price Code/Year

2018 International Building Code (IBC) or International Residential Code (IRC)

Soil Bearing Capacity 1200 psf

Frost Depth 3’00” Footings must extend below frost depth

Seismic Zone C or D Wind Speed 115.00 mph Ground Snow Load 91 psf Design Roof Snow Load 75 psf Thermal Condition N/A

Solicitation No.: 1240LT23Q0089

USDA FOREST SERVICE, R-4

Bird Creek Shade Pre-Engineered Shade Pavilion

SECTION 033015 – CONCRETE FOR MINOR STRUCTURES

PART 1 - GENERAL

1.1 SUMMARY

A. This work shall consist of furnishing, placing, and finishing concrete in accordance with these specifications in the construction of all types of concrete structures and flat work to the lines, grades, and details shown on the drawings.

1.2 SUBMITTALS

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

1.3 MEASUREMENT AND PAYMENT

A. Measurement of concrete will by one or more of the following methods as indicated in the Schedule of Items.

B. Cubic Yards - The quantity to be measured shall be cubic yards of either "Nonreinforced Concrete" or "Reinforced Concrete." In either case, the concrete will be measured in accordance with the dimensions shown on the drawings or such other dimensions as may be ordered in writing by the Contracting Officer. No deduction will be made for the volume occupied by bar reinforcing steel or structural steel in the concrete.

C. Lump Sum - The quantity of either reinforced or nonreinforced concrete will be measured as a lump sum item when so designated in the Schedule of Items. In this case, there will be no volumetric measurement of concrete. The item will be measured as each structure, complete with reinforcing steel in place and finished as shown on the drawings and accepted by the Contracting Officer.

D. Included as Part of Another Lump Sum - The quantity of reinforced or nonreinforced concrete may be included as part of another lump sum item. In this case, there will be no measurement or payment for concrete under this specification.

E. No Measurement - When this specification is used as an appendage for an item which is bid as a separate item, there will be no measurement for this Section.

1.4 REFERENCE SPECIFICATIONS

A. Reference Specifications - 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.

B. ASTM A185 Standard Specification for Steel Welded Wire Reinforcement, Plain, for Concrete

Solicitation No.: 1240LT23Q0089

C. ASTM A615 Standard Specification for Deformed and Plain Billet-Steel Bars for Concrete Reinforcement

D. ASTM A996 Standard Specification for Rail-Steel and Axle-Steel Deformed Bars for Concrete Reinforcement

E. ASTM C31 Standard Practice for Making and Curing Concrete Test Specimens in the Field

F. ASTM C39 Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens

G. ASTM C143 Standard Test Method for Slump of Hydraulic Cement Concrete

H. ASTM C150 Standard Specification for Portland Cement

I. ASTM C309 Standard Specification for Liquid Membrane-Forming Compounds for Curing Concrete

J. AASHTO T2 Sampling of Aggregates

K. AASHTO T11 Materials Finer Than 75-µm (No. 200) Sieve in Mineral Aggregates by Washing

L. AASHTO T19 Unit Weight and Voids in Aggregate

M. AASHTO T21 Organic Impurities in Fine Aggregates for Concrete

N. AASHTO T27 Sieve Analysis of Fine and Coarse Aggregates

PART 2 - PRODUCTS

2.1 GENERAL

A. Concrete shall be composed of Portland cement, fine aggregate, coarse aggregate, air entraining agent, and water mixed in proportions approved by the Contracting Officer.

The concrete shall have a minimum compressive strength of 3750 psi at 28 days.

Solicitation No.: 1240LT23Q0089

B. All concrete shall be "Class A" concrete, unless otherwise specified.

Class A Concrete Mix

Cement Content 6.5 bags per cubic yard minimum Coarse Aggregate Size Range

1-1/2-inch to No. 4 standard or 1-inch to No. 4 alternative

Maximum Water-Cement Ratio

5.5 gallons per bag of cement

Slump Range 1-inch to 3-inch for standard coarse aggregate and 2-inch to 4-inch for alternative aggregate

Required Entrained Air 4-percent to 6-percent Approximate weight of ag-gregates per bag of cement*

140 lb. rounded FA or 155 lb. angular FA 330 lb. rounded CA or 305 lb. angular CA

*Aggregate weight given in saturated surface dry condition. (Specific gravity of aggregate to be approximately 2.65 and fineness modulus to be 2.75.)

C. *Aggregate weight given in saturated surface dry condition. (Specific gravity of aggregate to be approximately 2.65 and fineness modulus to be 2.75.)

D. The amount of water to be added to the mix shall be reduced by the amount of any excess moisture content in the fine aggregate to obtain the net water content.

E. Weight proportioning by the Contractor will be required for all concrete. Unless otherwise permitted, the cement shall be packed in bags containing 94 pounds net weight. Batches shall be used which do not require fractional bags of cement, except when a half-bag mix is permitted. The fine and coarse aggregate shall be weighed separately.

2.2 CEMENT

A. The cement shall be Portland cement, Type I, or Type II, and shall comply with ASTM C150. When high early strength cement is required, or permitted, it shall comply with ASTM C150, Type III.

B. The cement shall be shipped in the original manufacturer's packages and shall be in good condition when inspected by the Contracting Officer. The name and brand of the manufacturer and the type shall be plainly indicated thereon.

C. The Contractor shall add an air entraining agent to Type I, Type II, or Type III Portland cement. The Contracting Officer shall approve in writing the air entraining agent as well as the measuring and mixing procedure used by the Contractor. The Contracting Officer may require the Contractor to furnish a sample of the air entraining agent for testing purposes. All air entraining agents used shall be delivered in sealed containers with the manufacturer's name and type plainly indicated thereon.

D. The cement must be protected from rain and moisture, and any cement damaged by moisture or failure to meet any of the requirements of ASTM specifications shall be rejected and immediately removed from the work. All broken bags shall be rejected.

Cement stored by the Contractor for a period longer than 60-days shall be inspected by the Contracting Officer before used on the work.

Solicitation No.: 1240LT23Q0089

2.3 COLORING

Not used.

2.4 FINE AGGREGATE

A. Fine aggregate shall consist of clean, hard, durable, uncoated grains of sand, and shall be washed when necessary to obtain conformity with these specifications. Fine aggregate shall be well graded and when tested by means of laboratory sieves according to AASHTO T27 shall conform to the following requirements:

Fine Aggregate Grading US Std. Sieve Size Percent Passing by Weight

3/8-inch 100 No. 4 sieve 95-100 No. 16 sieve 50-85 No. 50 sieve 10-30 No. 100 sieve 2-10

B. Fine aggregate shall not have deleterious substances in excess of the following percentages:

Deleterious Substance Percent by Weight Clay Lumps 1.0 Coal and Lignite 1.0 Material passing No. 200 sieve (AASHTO T11) 3.0 Other (such as shale, mica, alkali, coated grains, soft particles 1.0

1. The above gradation represents the extreme limits which shall determine suitability for use from all sources of supply. The gradation from any one source shall be reasonably uniform and not subject to the extreme percentages of gradation specified above. Fine aggregate from different sources of supply shall not be mixed or stored in the same pile nor used alternately in the same class of construction or mix, without approval of the Contracting Officer.

2.5 COARSE AGGREGATE

A. Shall consist of gravel and be washed when necessary to obtain conformity with these specifications.

B. The maximum amounts of individual deleterious substances shall not exceed the following values:

Solicitation No.: 1240LT23Q0089

Deleterious Substance Percentage by Weight Material passing No. 200 sieve 1.0 Coal 1.0 Clay Lumps 0.5 Thin or Elongated Pieces 15.0 Soft Fragments 2.0 Other (such as alkali coated, friable, shale, or laminated)

3.0

1. An elongated piece is one whose length is more than five times its average thickness.

2. The maximum amount of any combination of the deleterious substances, other than thin or elongated pieces listed above, shall not exceed five percent by weight.

C. Coarse aggregate shall be well graded, and unless otherwise provided in the supplemental specifications, shall conform to the following grading requirements when tested with laboratory sieves, according to AASHTO T27.

Coarse Aggregate - "Standard" Gradation U.S. Standard Sieve Size Percentage (%) by Weight

Passing Sieves 1-1/2 inch 95-100 3/4 inch 35-70 3/8 inch 10-30

No. 4 0-5

Coarse Aggregate - "Alternate" Gradation (For use in heavily reinforced walls and walls less than 8" thick)

Sieve Designation Square Openings

Percentage (%) by Weight Passing Sieves

1 inch 95-100 ½ inch 25-60 No. 4 0-10 No. 8 0-5

1. If the alternate gradation for coarse aggregate is used, the Contractor must obtain prior approval in writing from the Contracting Officer.

2.6 WATER

A. Water shall be fresh, clean, and free from alkali (and other deleterious materials).

2.7 STEEL REINFORCEMENT

A. All reinforcing steel shall be deformed steel bars conforming to ASTM A615, ASTM A616, and ASTM A617, minimum grade 40, unless otherwise shown on the drawings.

Wire and wire mesh, when used as reinforcement in concrete, shall conform to ASTM A185.

Solicitation No.: 1240LT23Q0089

2.8 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.

PART 3 - EXECUTION

3.1 EQUIPMENT

A. All equipment, tools, and machinery used in doing the work shall be of approved design, shall be in good mechanical condition, and shall be maintained in a satisfactory working condition. The Contractor shall furnish sufficient equipment to (a) make a continuous pour between construction joints, and (b) place and consolidate each layer before the preceding layer has taken its initial set.

B. Mixer - The mixer shall be of a batch type of the size and design approved by the Contracting Officer, which will insure a uniform distribution of the materials throughout the mass and shall have a rated capacity of not less than a one-bag batch.

Where the quantity of concrete to be placed is small, the use of a half-bag mixer will be permitted. When large continuous pours are to be made, a second mixer should be either on the job or arrangements made so that it can be rapidly moved to the site of the work in case of a breakdown, insuring an uninterrupted pour.

C. Batching Equipment - The equipment used for weighing materials shall provide convenient and positive means of determining the quantities in the batch of concrete, and means shall be provided for the addition or removal of small quantities of materials to obtain the exact weight of ingredients per batch. The device for measuring water shall show accurately the quantity in pounds or in gallons.

3.2 FORMWORK

A. Forms shall be clean inside, accurately set and properly secured. Forms shall be sufficiently tight and rigidly constructed to contain the concrete without leakage or distortion. Forms for concrete exposed as a finished surface shall have smooth faces with tight, flush joints. Forms shall be left in place until the concrete is safely self-supporting, and then shall be removed without damage to the concrete.

3.3 PLACING REINFORCING STEEL

A. Reinforcing bars and members shall be accurately shaped and placed, as indicated on the drawings. Bars shall overlap as shown on the drawings or a minimum of 24 diameters at all splices and be securely wired and shall be firmly held in place during the placing of the concrete by spacers, chairs, or other suitable supports. Extreme care

Solicitation No.: 1240LT23Q0089 shall be taken to embed steel in concrete not less than 1-1/2 inches from the finished concrete surface at any point, unless otherwise shown on the drawings.

3.4 JOB MIXING

A. All concrete shall be mixed for a period of not less than 1-1/2 minutes after all materials, including water, are in the mixer. During the period of mixing, the mixer shall operate at the speed for which it was designed, but this speed shall be not less than 14 nor more than 20 revolutions per minute.

B. The entire contents of the mixer shall be removed from the drum before materials for the succeeding batch are placed therein. No mixer shall be operated above its rated capacity, and no mixer of a rated capacity of less than one bag shall be used, except as otherwise specified.

C. The first batch of concrete materials placed in the mixer shall contain a sufficient excess of cement, sand, and water to coat the inside of the drum without reducing the required mortar content of the mix. Upon the cessation of mixing for a considerable period, the mixer shall be thoroughly cleaned.

D. Concrete shall be mixed only in such quantities as are required for immediate use and shall be placed while fresh. Any concrete in which initial set has begun shall be wasted.

Retempering of concrete will not be allowed.

E. Hand-mixing will not be permitted, except by written permission from the Contracting Officer.

3.5 READY MIXED

A. Ready-mixed concrete may be used, provided that the materials are handled, measured, and batched as specified and provided that the methods described below are complied with.

B. Delivery of concrete shall be so regulated that placing is at a continuous rate, unless delayed by the placing operations. The intervals between delivery of batches for a continuous pour shall not be so great as to allow the concrete already in place to partially harden, and in no case shall an interval exceed 30 minutes.

C. In the event ready-mixed concrete is used, the supplier shall furnish, with each truckload, a certificate showing:

1. Amount (by weight) - Cement in each load

2. Amount (by weight) - Fine aggregate in each load

3. Amount (by weight) - Coarse aggregate in each load

4. Amount (by weight) - Water in each load

5. Time of day cement was added to the aggregate and water.

D. These certificates shall be handed to the Contracting Officer or authorized representative on the job.

Solicitation No.: 1240LT23Q0089

3.6 TRUCK MIXING

A. Truck mixers, unless otherwise authorized, shall be of the revolving drum type, watertight, and so constructed that the concrete can be mixed to insure a uniform distribution of materials throughout the mass and the discharging of concrete without segregation. All solid materials for the concrete shall be accurately measured by weight and charged into the drum at the proportioning plant. Except as subsequently provided, the truck mixer shall be equipped with a tank for carrying mixing water. Only the prescribed amount of water shall be placed in the tank, unless the tank is equipped with a device by which the quantity of water added can be readily verified.

B. The mixing water may be added directly to the batch, in which case a tank will not be required. Truck mixers may be required to be provided with means by which the mixing time can be readily verified by the Contracting Officer.

C. The maximum size of batch in truck mixers shall not exceed the maximum rated capacity of the mixer, as stated by the manufacturer and stamped in metal on the mixer.

Each truck mixer shall be equipped with an approved device for registering the number of revolutions made by the drum during the interval between introduction of the cement and/or water into the drum and discharge of concrete from the mixer. The drum shall revolve continuously during the interval. The mixing speed of the drum shall not be less than four nor more than fifteen revolutions per minute.

D. The agitating speed of the drum shall be not less than two nor more than six revolutions per minute. Mixing shall commence immediately after the cement has been added to the water and aggregate, and shall continue at mixing speed for at least fifty revolutions of the drum. The drum shall revolve without interruption until the concrete has been discharged.

E. Concrete transported in a truck mixer or agitator shall be discharged at the job and placed in its final position in the forms within 1-1/2 hours after the introduction of the cement to the water and aggregate, except that in hot weather or under other conditions contributing to quick stiffening of the concrete (mix temperatures above 72o F.), the maximum allowable time shall be reduced to 45 minutes (by the Contracting Officer).

The maximum volume of mixed concrete transported in an agitator shall be in accordance with the specified rating.

3.7 PLACING CONCRETE

A. No concrete shall be deposited in the forms until all reinforcing steel, ducts, and anchorages have been placed and inspected by the Contracting Officer or authorized representative.

B. The Contractor shall notify the Contracting Officer a minimum of 24 hours prior to placing concrete.

C. The Contractor will prepare a minimum of two 6" diameter x 12" long concrete test cylinders from each 5 cubic yards placed, or fraction thereof, to determine if the minimum acceptable compressive strength is achieved. The Contractor shall have

Solicitation No.: 1240LT23Q0089 compressive tests performed on all cylinders, at time intervals as requested by the Contracting Officer. A copy of the test results shall be submitted to the Contracting Officer.

D. Surfaces on which concrete is to be placed shall be thoroughly moistened with water immediately before placing concrete.

E. No concrete shall be placed in water. All standing water shall be removed prior to the placement of the concrete.

F. The placing of concrete shall start at the low point and shall proceed upgrade, unless otherwise permitted by the Contracting Officer.

G. All concrete shall be placed while fresh and before it has taken an initial set.

Retempering any partially hardened concrete with additional water will not be permitted.

H. Mixed concrete, after being deposited, shall be consolidated (tamped and spaded or vibrated) until all voids are filled and free mortar appears on the surface. All concrete in walls greater than 18" in height shall be consolidated with suitable mechanical vibrators. Vibrating shall be supplemented by hand spading and adequate compaction to insure against any voids or honeycomb. The concrete shall be placed as nearly as possible in its final position and the use of vibrators for extensive shifting of the mass of fresh concrete will not be permitted. Fresh concrete shall not be permitted to fall from a height greater than six feet without the use of adjustable-length pipes or chutes.

I. The use of chutes will be allowed only when they are laid at such inclination as will permit the flow of concrete of such consistency as is required. The use of additional water in the concrete to promote free flow in chutes of low inclination will not be allowed.

J. No precipitation shall be allowed to fall on concrete surfaces (floors, roofs, sidewalks, driveways, etc.) until the concrete has set at least 24-hours.

3.8 FINISHING CONCRETE

A. Ordinary surface finish shall be applied to all concrete surfaces either as a final finish or preparatory to a higher class finish. Ordinary surface finish, unless otherwise specified, shall be considered as a final finish. The ordinary surface finish shall begin by striking off the concrete to the proper grade for elevation and drainage, as shown on the drawings. The surface shall then be floated to bring a smooth blanket of mortar paste to the surface and cover all the coarse aggregate. Surfaces covered by form work shall have all fins removed and all holes and depressions cleaned and filled with grout. On surfaces which are to be buried underground or surfaces which are enclosed, the removal of fins and form marks and the rubbing of mortared surfaces to a uniform color and floating will not be required.

B. The following items, and those shown on the drawings, shall receive additional or special finishing:

Solicitation No.: 1240LT23Q0089

1. Walls of Structures to Contain Liquid - Should voids or honeycomb be present after forms are removed, the Contractor shall, at his expense, remove and/or repair any such structure or area to ensure that a structurally sound, water tight structure is provided. Solid walls shall be given the finish indicated under Foundations.

2. Foundations - All concrete foundations above grade, and for a distance of 4" to 6" below finished grade, shall be dressed by either (a) covering with grout composed of a mixture of one part sand and one part cement, mixed to a cream-like consistency and brushed on while the foundation is still green, or (b) rub down with a wood trowel and water while still green to make an even sand finish appearance.

3. Floors - All concrete floors shall be steel troweled to a hard, smooth, even finish without trowel or chatter marks.

4. Sidewalks and Driveways - All concrete sidewalks and driveways shall be troweled as described under floors. The troweled surface shall be roughened with a soft broom to provide a non-slip light broom surface.

5. All edges shall be finished with an edging tool.

6. Expansion Joints - Expansion joints shall be placed as shown on the drawings.

All edges shall be finished with an edging tool. The joint space shall be 3/8-inch minimum and shall be filled with asphalt impregnated fiberboard.

3.9 PROTECTION FROM COLD

A. No concrete shall be placed when the ambient air temperature is below 35° F., unless permission to do so is given in writing by the Contracting Officer. In all cases, the Contractor shall insure that the air, or water as allowed in Section 033015, surrounding the fresh concrete, be kept at a temperature above 50° F. for a period of 5 days, or above 70° F. for three days, after the concrete is placed.

B. Sufficient heating apparatus, such as stoves, salamanders, or steam equipment, and fuel to furnish all required heat, shall be supplied. All water used for mixing concrete shall be heated to a temperature of at least 60° F., but not over 150° F. Aggregate shall be heated either by steam or by dry heat to a temperature of at least 60° F., but not over 150° F. The heating apparatus shall be such as to heat the mass uniformly and preclude the possibility of the occurrence of hot spots which will burn the material. The temperature of the mixed concrete shall be not less than 60° F., nor more than 100° F., at the time of placing in the forms.

C. The Contractor will not be allowed to use calcium chloride in the concrete.

3.10 REMOVAL OF WATER

A. Water shall not be allowed to rise over concrete until the concrete has set at least 24 hours. No flowing water shall be permitted to contact the concrete until it has set for at least seven days. Any damage to concrete or connecting structures or item, caused by water entering or raising, shall be repaired by the Contractor at his expense.

3.11 CURING

Solicitation No.: 1240LT23Q0089

A. The concrete shall be protected against frost and rapid drying, and kept moist for a curing period of at least six days after placing. Concrete, from which forms are removed within six days after placement, and flat work, shall be sprayed during the curing period, as frequently as conditions may require to prevent drying out.

B. Impervious curing compounds may be used in lieu of water-curing subject to written approval by the Contracting Officer. When used, all surfaces shall be given the required surface finish prior to application of the impervious curing compound. During the surface finish process, the concrete shall be protected by the water-curing method.

C. The impervious curing compound shall meet all specification requirements of ASTM C309.

D. Concrete which is to be lined with fiberglass shall not be treated with a curing compound which contains any wax. (Nonvolatile portions of Class A vehicles may contain wax. Nonvolatile portions of Class B vehicles are resin material.)

E. The rate of application shall be not less than one gallon of liquid coating per 200 square feet of concrete surface or as recommended by the manufacturer, and all concrete cured by this method shall receive two such applications of the curing compound.

F. The first coat shall be applied immediately after stripping of forms and acceptance of the concrete finish. If the surface is dry, the concrete shall be thoroughly wet with water and the curing compound applied just as the surface film of water disappears.

The second application shall be applied after the first application has set. During curing operations, any unsprayed surfaces shall be kept wet with water.

G. The coating shall be protected against marring or traffic for a period of at least 6-days after application. When applied to sidewalks, curbs, or roadways, the coating shall not be walked on, no concrete buggies or wheelbarrows allowed to pass over it, nor shall it be otherwise disturbed. Any coating so marred or otherwise disturbed shall be given an additional coating. Should the coating be subjected continuously to injury, the Contracting Officer reserves the right to require the water-curing be applied.

3.12 SAMPLING AND TESTING

A. Each truck load shall be tested with at least one slump test in accordance with ASTM C143 with additional slump tests if any water or other materials are subsequently added or if initial test fails. All concrete placed which fails slump tests, is placed at contractor's risk and is subject to removal if cylinders made subsequently fail testing.

B. A minimum of 3 concrete cylinders shall be made and cured in accordance with ASTM C31. The first cylinder shall be tested in 7 days, the second cylinder shall be tested in 28 days. If either test fails, the third test shall be also tested in 28 days. Cylinder testing shall be in accordance with ASTM C39.

END OF SECTION

August 2023

Solicitation No.: 1240LT23Q0089

SECTION 022220 – STRUCTURAL EXCAVATION, BACKFILL, AND COMPACTION

PART 1 - GENERAL

1.1 SUMMARY

A. Includes structure excavation, special fills, backfill, and compaction.

1.2 PROTECTION

A. Protect excavations from accumulation of water. If clay soil becomes saturated, compact after it has dried as specified herein.

B. Protect excavations from freezing. If frost action occurs, compact ground after thawing as specified herein.

C. Provide shoring and bracing as necessary to protect structures, employees, and the public.

1.3 REFERENCES

29 CFR Safety and Health Regulations for Construction

ASTM D698 Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Standard Effort (12,400 ft-lbf/ft3 (600 kN-m/m3))

ASTM D1557 Standard Test Methods for Laboratory Compaction Characteristics of Soil Using Modified Effort (56,000 ft-lbf/ft3 (2,700 kN-m/m3))

1.4 RELATED WORK - The work shall be in accordance with the following subsidiary specifications. The subsidiary specifications are referred to in the text by the Section designation only.

A. Section 02102 Clearing and Grubbing

PART 2 - PRODUCTS

2.1 BACKFILL AND FILLS - Excavation is unclassified as to materials and shall include all materials which are encountered in the required excavation.

A. Use the excavated material as specified below:

1. Remove rocks over 8 inches in maximum dimension, ice or frozen earth, muck, perishable debris, and earth with high void content.

2. Remove rocks over 2 inches in maximum dimension for backfill placed within 12 inches of foundation.

3. Materials removed in stripping shall not be used for backfill.

2.2 GRAVEL AND FILLS

A. Clean pit-run gravel uniformly graded with less than 5% minus #200 material, 2 inches maximum size, free of deleterious materials.

B. Clean sand, uniformly graded, free of deleterious materials.

2.3 IMPORTED MATERIAL - When the Contractor is required to import material, it shall be from a designated source or source approved by the Contracting Officer. All imported material requiring compaction when placed, shall be tested in accordance with ASTM D 698 method C or D, or ASTM D 1557, method C or D as required in paragraph 3.4 below.

PART 3 - EXECUTION

3.1 EXCAVATION

A. Perform to the lines, grades, and elevations indicated. Extend excavation a sufficient distance from walls and footings to allow for safety, placing and removal of forms, installation of services, and for inspection. Provide proper depth with allowance made for gravel fills formed voids and concrete flatwork.

1. Bottoms for piers, footings, and foundation walls shall be level, clean, true to size, and clear of loose materials.

2. Pier excavations shall be drilled or otherwise accurately formed.

3. If excavations for foundations are carried below the specified levels, extend the foundation to the excavated level.

3.2 CONSERVING TOPSOIL - Topsoil shall be removed from the area to be excavated and from the area where excavated material will be piled prior to excavating. Topsoil shall be kept separate from excavated material. Topsoil will be reused on those areas from which it came after backfilling and embankment construction is complete.

3.3 BACKFILLING

A. Place and compact fills and backfills adjacent to structures in such a manner as to prevent wedging action or eccentric lodging upon or against the structures.

1. Remove forms, and clean the excavation of trash and debris prior to backfilling.

2. Do not place backfill against any concrete footings or wall without prior permission of the Contracting Officer (CO) and in no case less than 7 days after completion of the wall or footings.

3. Place backfill in horizontal layers not more than 12 inches thick with the proper moisture content for the required degree of compaction. Flooding or puddling not allowed. Compact each layer as specified. Backfill layer thickness under concrete flatwork limited to 6 inches maximum.

Solicitation No.: 1240LT23Q0089

4. Heavy equipment for spreading and compacting backfill shall not be operated closer to a wall than a distance equal to the height of the backfill above the top of the footing.

5. Provide for anticipated settlement and shrinkage of the backfill and for the finished grades required, including topsoil grading.

6. Prepare subgrades for gravel fill areas level and free from soft spots. Place and compact earthfill where required to raise subgrade. Place gravel to the lines and grades shown. Compact the gravel sub-base as specified until a smooth, uniform use surface is obtained.

3.4 COMPACTION

A. Compact each layer to following percentages of maximum density determined by ASTM D1557 method C or D.

1. Under footings: 95%.

2. Under concrete flatwork: 90%.

3. All other areas: 85%.

END OF SECTION 022220

August 2023