S02 - Attachment 18 - 320523 Cement and Concrete for Exterior Improvements.pdf

Audie L. Murphy Memorial Veterans’ Hospital EHRM Infrastructure Upgrades

Project No. 671-22-700 Addendum 1

August 24, 2023

32 05 23 - 1 Cement and Concrete for Exterior Improvements

SECTION 32 05 23

CEMENT AND CONCRETE FOR EXTERIOR IMPROVEMENTS

PART 1 - GENERAL

1.1 SUMMARY

A. Section Includes:

1. Equipment Pads: Condensing Units.

1.2 RELATED REQUIREMENTS

A. Field Testing: Section 01 45 29, TESTING LABORATORY SERVICES.

1.3 APPLICABLE PUBLICATIONS

A. Comply with references to extent specified in this section.

B. American Association of State Highway and Transportation Officials (AASHTO):

1. M147-65-UL-04 - Materials for Aggregate and Soil-Aggregate Subbase, Base and

Surface Courses.

C. American Concrete Institute (ACI):

1. 305R-10 - Guide to Hot Weather Concreting.

2. 306R-10 - Guide to Cold Weather Concreting.

D. American National Standards Institute (ANSI):

1. B101.3 - Wet DOCF of Common Hard Surface Floor Materials (Including Action and

Limit Thresholds for the Suitable Assessment of the Measured Values).

E. ASTM International (ASTM):

1. A615/A615M-16 - Deformed and Plain Carbon Steel Bars for Concrete

Reinforcement.

2. A996/A996M-15 - Rail-Steel and Axle-Steel Deformed Bars for Concrete

Reinforcement.

3. A1064/A1064M-16 - Carbon-Steel Wire and Welded Wire Reinforcement, Plain and

Deformed, for Concrete.

4. C33/C33M-16 - Concrete Aggregates.

5. C94/C94M-16 - Ready Mixed Concrete.

6. C143/C143M-15a - Slump of Hydraulic Cement Concrete.

7. C150/C150M-16 - Portland Cement.

8. C171-16 - Sheet Materials for Curing Concrete.

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9. C309-11 - Liquid Membrane Forming Compounds for Curing Concrete.

10. C494/C494M-15a - Chemical Admixtures for Concrete.

11. C618-15 - Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use in Concrete.

12. C979/C979M-16 - Pigments for Integrally Colored Concrete.

13. C989/C989M-14 - Slag Cement for Use in Concrete and Mortars.

14. C1240-15 - Silica Fume Used in Cementitious Mixtures.

15. D1751-04(2013)e1 - Preformed Expansion Joint Filler for Concrete Paving and

Structural Construction (Nonextruding and Resilient Bituminous Types).

16. D5893/D5893M-10 - Cold Applied, Single Component, Chemically Curing Silicone

Joint Sealant for Portland Cement Concrete Pavements.

17. D6690-15 - Joint and Crack Sealants, Hot Applied, for Concrete and Asphalt

Pavements.

1.4 SUBMITTALS

A. Submittal Procedures: Section 01 33 23, SHOP DRAWINGS, PRODUCT DATA, AND

SAMPLES.

B. Submittal Drawings:

1. Show size, configuration, and fabrication and installation details.

2. Show reinforcing.

C. Manufacturer's Literature and Data:

1. Description of each product.

2. Installation instructions.

D. Test reports: Certify products comply with specifications.

1. Concrete materials.

E. Certificates: Certify products comply with specifications.

1. Reinforcement.

2. Curing materials.

F. Concrete mix design.

G. Proposed hot and cold weather concreting methods.

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1.5 QUALITY ASSURANCE

A. Installer Qualifications:

1. Regularly installs specified products.

2. Select subbase job-mix design. Report the following:

a. Material sources.

b. Gradation.

c. Plasticity index.

d. Liquid limit.

e. Laboratory compaction curves indicating maximum density at optimum moisture content.

1.6 DELIVERY

A. Deliver steel reinforcement to prevent damage.

B. Before installation, return or dispose of distorted or damaged steel reinforcement.

C. Bulk Products: Deliver bulk products away from buildings, utilities, pavement, and existing turf and planted areas. Maintain dry bulk product storage away from contaminants.

1.7 STORAGE AND HANDLING

A. Store products indoors in dry, weathertight facility.

B. Protect products from damage during handling and construction operations.

1.8 FIELD CONDITIONS

A. Hot Weather Concreting Procedures: ACI 305R.

B. Cold Weather Concreting Procedures: ACI 306R.

1. Use non-corrosive, non-chloride accelerator admixture.

2. Do not use calcium chloride, thiocyanates or admixtures containing more than 0.05 percent chloride ions.

1.9 WARRANTY

A. Construction Warranty: FAR clause 52.246-21, "Warranty of Construction."

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PART 2 - PRODUCTS

2.1 CONCRETE MATERIALS

A. Portland Cement: ASTM C150/C150M, Type II.

B. Coarse Aggregate: ASTM C33/C33M; size to suit application.

C. Fine Aggregate: ASTM C33/C33M.

D. Mixing Water: Fresh, clean, and potable.

E. Air-Entraining Admixture: ASTM C260/C260M.

F. Chemical Admixtures: ASTM C494/C494M.

G. Reinforcing Steel: ASTM International (ASTM) A615/A615M, Grade 60.

H. Sheet Materials for Curing Concrete: ASTM C171.

2.2 FORMS

A. Forms: Wood, plywood, metal, or other materials, approved by Contracting Officer's

Representative, of grade or type suitable to obtain type of finish specified.

1. Plywood: Exterior grade, free of defects and patches on contact surface.

2. Lumber: Sound, grade-marked, S4S stress graded softwood, minimum 50 mm

(2 inches) thick, free from warp, twist, loose knots, splits, or other defects.

3. Form Coating: As recommended by Architect/Engineer.

B. Provide forms suitable in cross-section, depth, and strength to resist springing during depositing and consolidating concrete.

1. Do not use forms varying from straight line more than 3 mm in 3000 mm (1/8 inch in

10 feet), horizontally and vertically.

C. Provide flexible or curved forms for forming radii.

2.3 CONCRETE CURING MATERIALS

A. Concrete curing materials, conform to one of the following:

1. Sheet Materials for Curing Concrete: ASTM C171.

2. Curing Compound: ASTM C309, Type 1 clear liquid membrane forming type, without paraffin or petroleum.

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2.4 CONCRETE MIXES

A. Design concrete mixes according to ASTM C94/C94M, Option C.

B. Concrete Type: Non-air-entrained. See Table I.

C. Maximum Slump: ASTM C143/C143M. See Table II.

TABLE II - MAXIMUM SLUMP

APPLICATION MAXIMUM SLUMP

Equipment Pad 75 to 100 mm (3 to 4 inches)

2.5 ACCESSORIES

A. Equipment and Tools: Obtain Contracting Officer's Representative's, approval of equipment and tools needed for handling materials and performing work before work begins.

B. Maintain equipment and tools in satisfactory working condition.

TABLE I - CONCRETE TYPES

Concrete

Type

Minimum 28 Day

Compressive

Strength f'c

MPa (psi)

Non-Air-Entrained Air-Entrained

Min. Cement kg/cu. m (lbs./cu.

yd.)

Max.

Water

Cement

Ratio

Min. Cement kg/cu. m (lbs./cu.

yd.)

Max.

Water

Cement

Ratio

A 35 (5000)1,3 375 (630) 0.45 385 (650) 0.40

B 30 (4000)1,3 325 (550) 0.55 340 (570) 0.50

C 25 (3000)1,3 280 (470) 0.65 290 (490) 0.55

D 25 (3000)1,2 300 (500) * 310 (520) *

Footnotes:

1. If trial mixes are used, achieve compressive strength 8.3 MPa (1,200 psi) in excess of f'c.

For concrete strengths greater than 35 MPa (5,000 psi), achieve compressive strength

9.7 MPa (1,400 psi) in excess of f’c.

2. For Concrete Exposed to High Sulfate Content Soils: Maximum water cement ratio is 0.44.

3. Laboratory Determined according to ACI 211.1 for normal weight concrete.

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PART 3 - EXECUTION

3.1 PREPARATION

A. Examine and verify substrate suitability for product installation.

B. Protect existing construction and completed work from damage.

C. Prepare, construct, and finish subgrade. As required.

D. Maintain subgrade in smooth, compacted condition, in conformance with the required section and established grade until the succeeding operation has been accomplished.

3.2 SETTING FORMS

A. Form Substrate:

1. Compact form substrate to uniformly support forms along entire length.

2. Correct substrate imperfections and variations by cutting, filling, and compacting.

B. Form Setting:

1. Set forms to indicated line and grade with tight joints. Rigidly brace forms preventing movement.

2. Remove forms when removal will not damage concrete and when required for finishing.

3. Clean and oil forms before each use.

4. Correct forms, when required, immediately before placing concrete.

C. Form Tolerances:

1. Variation from Indicated Line: Maximum 6 mm (1/4 inch).

2. Variation from Indicated Grade: Maximum 3 mm in 3000 mm (1/8 inch in 10 feet).

3.3 PLACING REINFORCEMENT

A. Keep reinforcement clean from contamination preventing concrete bond.

B. Install reinforcement shown on drawings.

C. Support and securely tie reinforcing steel to prevent displacement during concrete placement.

D. Obtain Contracting Officer's Representative's reinforcement placement approval before placing concrete.

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3.4 JOINTS - GENERAL

A. Place joints, where shown on approved submittal Drawings.

1. Conform to details shown.

2. Install joints perpendicular to finished concrete surface.

B. Make joints straight and continuous from edge to edge of pavement.

3.5 PLACING CONCRETE - GENERAL

A. Preparation before Placing Concrete:

1. Obtain Contracting Officer's Representative approval.

2. Remove debris and other foreign material.

3. Uniformly moisten substrate, without standing water.

B. Convey concrete from mixer to final location without segregation or loss of ingredients.

Deposit concrete to minimize handling.

C. During placement, consolidate concrete by spading or vibrating to minimize voids, honeycomb, and rock pockets.

1. Vibrate concrete against forms and along joints.

2. Avoid excess vibration and handling causing segregation.

D. Place concrete continuously between joints without bulkheads.

E. Install construction joint in concrete placement suspended for more than 30 minutes.

F. Replace concrete with cracks, chips, bird baths, and other defects to nearest joints, approved by Contracting Officer's Representative.

3.6 PLACING CONCRETE FOR EQUIPMENT PADS

A. Place concrete in one layer conforming to cross section shown on Drawings after consolidating and finishing.

B. Deposit concrete near joints without disturbing joints. Do not place concrete directly onto joint assemblies.

C. Strike concrete surface to proper section ready for consolidation.

D. Consolidate concrete by tamping and spading or with approved mechanical finishing equipment.

E. Finish concrete surface with wood or metal float.

F. Construct concrete pads with sufficient slope to drain, preventing standing water.

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3.7 FORM REMOVAL

A. Keep forms in place minimum 12 hours after concrete placement. Remove forms without damaging concrete.

B. Do not use bars or heavy tools against concrete to remove forms. Repair damage concrete found after form removal.

3.8 CONCRETE FINISHING - GENERAL

A. Follow operation sequence below, unless otherwise indicated on Drawings:

1. Consolidating, floating, striking, troweling, texturing, and joint edging.

B. Use edging tool with 6 mm (1/4 inch) radius, // unless otherwise shown on Drawings //.

C. Keep finishing equipment and tools clean and suitable for use.

3.9 CONCRETE FINISHING - EQUIPMENT PADS

A. Strike pad surface to elevation shown on Drawings.

B. Provide smooth, dense float finish, free from depressions or irregularities.

C. Finish pad edges with edger.

D. After removing forms, rub pad edge faces with wood or concrete rubbing block, removing blemishes, form marks, and tool marks and providing uniform color.

E. Pad Tolerances:

1. Variation from Indicated Plane: Maximum 3 mm in 3000 mm (1/8 inch in 10 feet).

2. Variation from Indicated Elevation: Maximum 6 mm (1/4 inch).

3. Variation from Indicated Thickness: Maximum 6 mm (1/4 inch).

F. Replace pads when pads exceed specified tolerances.

3.10 CONCRETE CURING

A. Concrete Protection:

1. Protect unhardened concrete from rain and flowing water.

2. Provide sufficient curing and protection materials available and ready for use before concrete placement begins.

3. Protect concrete to prevent pavement cracking from ambient temperature changes during curing period.

a. Replace pavement damaged by curing method allowing concrete cracking.

b. Employ another curing method as directed by Contracting Officer's

Representative.

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B. Cure concrete for minimum 7 days by one of the following methods appropriate to weather conditions preventing moisture loss and rapid temperature change:

1. Burlap Mat: Provide minimum two layers kept saturated with water during curing period. Overlap Mats at least 150 mm (6 inches).

2. Sheet Materials:

a. Wet exposed concrete surface with fine water spray and cover with sheet materials.

b. Overlap sheets minimum 300 mm (12 inches).

c. Securely anchor sheet materials preventing displacement.

3. Curing Compound:

a. Protect joints indicated to receive sealants preventing contamination from curing compound.

b. Insert moistened paper or fiber rope into joint or cover joint with waterproof paper.

c. Apply curing compound before concrete dries.

d. Apply curing compound in two coats at right angles to each other.

e. Application Rate: Maximum 5 sq. m/L (200 sq. ft./gallon), both coats.

f. Immediately reapply curing compound to surfaces damaged during curing period.

3.11 CLEANING

A. After completing curing:

1. Remove burlap and sheet curing materials.

2. Sweep concrete clean, removing foreign matter from the joints.

3. Seal joints as specified.

3.12 PROTECTION

A. Protect exterior improvements from traffic and construction operations.

1. Prohibit traffic on paving for minimum seven days after placement, or longer as directed by Contracting Officer's Representative.

B. Remove protective materials immediately before acceptance.

C. Repair damage.

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1. Replace concrete containing excessive cracking, fractures, spalling, and other defects within joint boundary, when directed by Contracting Officer's

Representative, and at no additional cost to the Government.

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