SECTION CONCRETE SIDEWALKS

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1 SECTION PART 1 - GENERAL 1.01 DESCRIPTION A. This Section specifies the requirements for forming and placing reinforced and unreinforced concrete as delineated on the Construction Drawings and as specified within this section and related sections of these specifications. The work includes, but is not limited to, the following: 1. Concrete sidewalks. 2. Special sidewalk finishes, textures, patterns, sandblasting, etching, imprinting, and special paving material borders. 3. Driveways and curb ramps. 4. Concrete coloring including color admixtures, stains, and color hardeners. 5. Concrete furniture pads, concrete borders, and miscellaneous paving surfaces. 6. Concrete surface overlay treatment 1.02 QUALITY ASSURANCE A. Finishing Tolerances 1. Finished surfaces shall have a tolerance of 1/8 in 10 feet as determined by a 10 foot straight edge placed anywhere on the slab. B. Reference Standards 1. The following specifications and standards of the latest issues listed below, but referred to thereafter by basic designation only, form a part of this specification to the extent indicated by the references thereto: 2. American Society for Testing and Materials Standards (ASTM): a). ASTM C 31 Standard Practice for making and curing Concrete Test Specimens in the field. b). ASTM C 39 Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens. c). ASTM C 42 Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of Concrete. d). ASTM C 138: Standard Test Method for Unit Weight, Yield, and Air Content (Gravimetric) of Concrete

2 e). ASTM C 143 Test Method for Slump of Hydraulic Cement Concrete. f). ASTM C 142 Practice for Sampling Freshly Mixed Concrete g). ASTM D 698 Standard Test Methods for Moisture Density Relations of Soils and Soils-Aggregate Mixtures Using 5.5-Pound Rammer and 12-inch Drop. 3. Americans With Disabilities Act( ADA ) 4. Texas Accessibility Standards C. Installer Qualifications: Concrete shall be finished by firm with five years experience with work of similar scope and quality. D. Bomanite Micro-topping installation 1. All work shall be installed by a Licensed Bomanite Contractor who shall provide a foreman or supervisor who has experience with and knowledge of special processes used to install Micro-Top. Evidence that the Bomanite Contractor is qualified to complete the project as specified herein shall be submitted to, and subject to approval of, the Architect/Designer. 2. The Licensed Bomanite Contractor shall provide a job-site sample (100 square feet or 9.3 square meters minimum) to be approved by the Landscape Architect or Owner s Representative prior to the start of the construction. Said sample shall be the standard for the balance of the work installed, and shall be protected against damage until final approval. The cost for the construction and protection of the sample shall be borne by the Contractor 1.04 SUBMITTALS A. Reinforcement Materials 1. Submittals shall conform to Division 1 Specifications. B. Submit certified testing results and certificates of compliance. C. The Contractor shall in addition provide manufacturer and product items information for the following items. 1. Pigments and Stains Submit manufacturer's color chart or sample chip set for the color selection; indicate pigment number and required dosage rate. Submittals are for general color selection and may vary somewhat from concrete finished in field according to Drawings and Specifications. 2. Curing compounds. 3. Patterning tools and templates of each type used. 4. Surface Retarder

3 5. Sealers and stains 6. Cleaners 7. Sandblasting equipment data D. Concrete Finish Mock-Up(s): 1. At location on Project selected by Landscape Architect or Owner s Representative, place and finish a minimum 4 x 4 feet area demonstrating materials, workmanship, and curing method to be used throughout Project for each special concrete finish. 2. Retain samples of cements and aggregates used in mock-up for comparison with materials used in remaining Work. 3. The Contractor shall make provisions to provide for up to two (2) additional mockups of each finish type to be determined by the Landscape Architect or Owner s Representative 4. Accepted mock-up provides visual standard for work of Section. 5. Mock-ups may remain as part of Work if approved and installed according to the Drawings and Specifications, otherwise, the Contractor shall remove the Mock-ups when no longer required for comparison with finished work MEASUREMENT AND PAYMENT A. Stipulated Price(Lump Sum): The Contract is a Stipulated Price Contract, payment for labor, materials, and all miscellaneous costs required as part of the work required in this Section is included in the total Stipulated Price. PART 2 MATERIALS 2.01 MATERIALS A. Concrete: Conform to material and proportion requirements for concrete of Sections & 2751S Concrete Paving. 1. Exceptions: with the exception of specially finished architectural pavement that may require special aggregates, mixes and finishes as specified herein. Where materials and procedures are referenced in this Section and/or on the Drawings, they shall take precedence over the requirements of Sections & 2751S Concrete Paving. B. Reinforcing Steel: Conform to material and proportion requirements for welded wire fabric of Sections & 2751S Concrete Paving.. C. Preformed Expansion Joint Material: Conform to material and proportion requirements for preformed expansion joint material of Section Concrete Pavement Joints

4 D. Expansion Joint Filler: Conform to material and proportion requirements for expansion joint filler of Section Concrete Pavement Joints. E. Sand blasting Templates: Conform to material requirements of Section Ornamental Metal and Fabrication F. Forms: Use straight, un-warped wood or metal forms with nominal depth equal to or greater than the proposed sidewalk thickness. The use of 2 by 4 lumber as forms will not be allowed. G. Sand Bed: Conform to material requirements for bank run sand of Section Utility Backfill Materials. H. Sodding: Conform to material requirements for sodding of Section Sodding DEFORMED CONTRACTION JOINT METAL STRIPS A. Deformed contraction joint metal strips shall be 28 ga. steel, galvanized 1.25 oz. per square foot or heavier and meet the specifications of ASTM A ARCHITECTURAL FINISHING AND ADMIXTURE PRODUCTS. A. ADMIXTURES 1. Integral Color Admixture: Contractor to add one of the following concrete color agents into the concrete mix. Concrete coloring agent shall be added at the manufacturer s recommend rates. Concrete coloring agent shall be mixed at the batch plant under controlled conditions. Contractor to adhere to ASTM C Integral Color Admixture Manufacturer: Brickform Liquid Integral Color, or approved equal 3. Special Concrete Aggregates: See specifications Sections and for aggregate type and size. 4. Use of Fly Ash: For concrete surfaces to receive staining, Contractor shall not utilize fly ash in the concrete mix. B. CONCRETE STAINS 1. Concrete staining material shall be an acid based stain capable of penetrating concrete surface in the colors specified on the Drawings. 2. Manufacturer/Applicator: All products shall be manufactured by C.S.I. Concrete Coatings Inc, 6331 Pleasant Stream, Katy, Texas, Attention Gary Fingleman (713) , or approved equal

5 C. CONCRETE SEALERS 1. All concrete surfaces that are integrally colored, surface applied color, stained, and/or concrete overlayed shall be treated with two coats of an approved solvent based sealer suitable for sealing stained concrete or concrete overlayed pavement surfaces. 2. Manufacturer: Contractor shall coordinate with manufacturer of concrete colorant(types as specified above) to determine the recommended sealer and number of coats required. D. CONCRETE MIX VERIFICATION 1. In addition to the requirements of this section, the Contractor shall verify with the manufacturer of the concrete colorant(types as specified above) to verify the type of concrete mix specified is consistent with the requirements of the concrete colorant manufacturer. E. BOMANITE MICROTOP 1. Bomanite of Houston 6617 Flintlock Rd Houston, TX (713) Micro-Top by Bomanite, a system that employs the use of a troweled-on integrally colored cementitious topping to resurface vertical and horizontal surfaces on both indoor and outdoor applications. Micro-Top is approximately 20 mils thick (about the thickness of a credit card) and utilizes a full spectrum of color choices that can incorporate simple or elaborate graphic design. The work is performed on the job site by trained and experienced technicians. 3. Material Notes a) A semi-rigid elastomeric crack filler, manufactured by an approved manufacturered shall be used to fill working cracks and construction joints. b) Sealer: All Micro-Top surfaces shall be sealed in accordance with the manufacturer s recommendations. c) Color to be selected PART 3 - EXECUTION 3.01 INSPECTION AND PREPARATION. A. The area to receive concrete shall have the sub-grade inspected for unstable areas and need for additional compaction. Do not begin walk, curb ramp, or driveway ramp construction until such deficiencies have been corrected

6 B. Excavate subgrade to the line, grade, and cross section shown on the Drawings. Remove soft spots and pumping soils and replace with fill material having a plasticity index between 7 and 20. B. Loose material shall be removed from the compacted subgrade prior to placing concrete, and subgrade uniformly dampened. C. Immediately after subgrade is prepared, cover with compacted sand bed to depth as shown on the Drawings. Lay concrete when sand is moist, but not saturated. D. Protect living trees, other plan growth, and features in accordance with Section 2562 Tree Preservation 3.02 SETTING OF FORMS. A. Forms shall be set to the line and grade indicated on the Drawings and shall be securely staked to maintain set position during depositing and curing of concrete. B. Forms shall be set in sufficient quantity to allow continuous progress of the concrete placement, and to ensure that forms shall remain in place not less than 24 hours. C. Forms shall be cleaned after each use and coated with an approved form release agent prior to each use INSTALLATION OF JOINTS AND REINFORCEMENT A. Reinforcement: Install No. 3 reinforcing steel bars on 18-inch centers longitudinally and transversely. Lay longitudinal bars in walk continuously, except through expansion joints. Support reinforcement with suitable concrete chairs with enough frequency to support bars in the middle of the slab vertically during placement of concrete. B. Walks shall be constructed in sections, of lengths and widths as indicated on the Drawings, with no section less than 8 feet long. Sections separated by joint fillers placed vertically and at right angles to the longitudinal axis of the walk. The maximum spacing of the expansion joint shall be approximately 24 feet. C. Expansion joint fillers shall be installed for the full length where walks or ramps abut rigid construction, and where obstructions protrude through walks or ramps PLACING CONCRETE A. The Concrete shall be installed to the slab thickness specified on the Drawings and tamp thoroughly with jitterbug tamp, or other acceptable method. Bring mortar to surface. B. Control joints, and/or expansion joints shall be provided in accordance with the Drawings

7 C. Joint surfaces shall be cleaned just prior to the installation of sealants, finishes, and associated items. Dirt, insecure coatings, moisture and other substances could interfere with the bond of the sealants, finishes, and associated items shall be removed. D. The top surface shall be finished according to item 3.04 and as indicated on the Drawings. The edges of joints shall be 1/8 deep and rounded using an edging tool having a radius of ¼. Score joints shall be placed in a regular pattern, or as indicated on the drawings and in item 3.04 E. Provide the specified concrete finish, color, banding, and/or texture as specified on the Drawings and in item F. After concrete has set sufficiently, refill space along sides of sidewalk to top of pavement with suitable material. Tamp until firm and solid. Dispose of excess material in accordance with Division 1 Specifcations. Repair driveways and parking lots damaged by sidewalk excavation in accordance with Section Pavement Repair and Resurfacing FINISHING OF COLORED OR PLAIN CONCRETE A. Broomed Finish: Pull broom across freshly floated or toweled concrete surface to produce light texture in straight lines perpendicular to main line of traffic. Do not dampen brooms. B. Sandblasting: 1. Allow concrete to cure to sufficient strength that it will not be damaged by blasting but not less than seven days. 2. Use a medium sandblasting technique to remove a maximum of 1/16 of the cement mortar from the surface and expose aggregate. 3. Contractor shall utilize a sandblasting machine capable of fine, precision control, and compatible for use with custom vinyl templates. 4. Metal templates shall be used for the sandblasting technique. Make sure that the metal template is free of oils and other contaminants that might inadvertently stain the concrete. C. Sawcutting: Saw cut joints shall be performed to a depth of 1/8 to ¼ deep with a width of 1/8. Saw cuts shall be performed in a smooth and continuous manner. D. Curing: Contractor shall not cure concrete with water, membranes, or non-approved compounds that can discolor concrete or impact the use of concrete stains or cementitious overlays E. Color Tolerances: Minor variations in appearance of colored concrete, which are similar to natural variations in color and appearance of unpigmented concrete, are acceptable

8 F. Concrete Staining: All products shall be provided by Concrete Coatings Inc, 6331 Pleasant Stream, Katy, Texas, Attention Gary Fingleman (713) , or approved equal. 1. The contractor shall submit the final stain color and application techniques on jobsite test samples to be approved by the Landscape Architect or Owner s Representative prior to installation. 2. The area to receive concrete staining be protected from pedestrian and construction activities while it is curing prior to staining. 3. All concrete surfaces designated in the plans or specifications as being chemically stained shall receive two applications of the color and type specified on the Drawings after the concrete has cured a minimum of 30 days or as specified by the manufacturer for the specific color type used. (or has cured sufficiently to meet moisture vapor emission requirements ). 4. The surface shall cleaned of all dirt, debris, and stains, and lightly sandlasting to open up the concrete pores. 5. Existing concrete to be stained shall, or if directed by the Landscape Architect Or Owner s Representative, cleaned with an approved concrete cleaner. 6. The concrete shall be dry prior to staining. Staining activities shall not take place if a significant rain event has occurred in the current work day period. 7. All chemically stained surfaces shall be sealed with 2-3 coats of an approved solvent based, clear sealer in accordance with the manufacturer recommendations. 8. All expansion joints in chemically stained flatwork shall be sealed using an approved sealant compatible with the type of joint sealant used in order to blend the joint with the predominant, surrounding stain color. H. Metal Templates for Sandblasted Patterns: All special metal templates for sandblasted graphics shall be fabricated by Blumenthal Sheet Metal, Houston, Texas, Attention Sonny Rose (713) Metal templates shall be clean, carbon steel and be plasma cut.(no water jet cutting will be allowed). I. Sealing Integral Colored Concrete: All architectural finished surfaces including, but not limited to, integral color, color hardened, overlays, stains, colored bandings, shall be sealed with an approved sealant. 1. Where sandblasted graphics are called for, seal concrete pavement prior to sandblasting. 2. After sandblasting graphic logo, stain logo(if specified) and reapply sealer of entire surface(both sandblasted and non sandblasted. Clean surfaces prior to sealing INSTALLATION OF BOMANITE MICRO-TOP A Installation Procedures

9 1. Powerwash existing concrete surface. 2. Concrete shall be tested in accordance with ASTM F and/or ASTM E (If concrete does not conform, call Bomanite Corporation for technical assistance.) 3. Exterior Concrete: Concrete cannot be effectively tested for vapor emission levels outdoors. If moisture problems are suspected, apply Bomanite Con-Shield following manufacturer s recommendations. Concrete subject to freeze/thaw conditions shall be treated with Bomanite Con-Shield according to manufacturer s recommendations. 4. Concrete shall have a ph level between 7-9. (If concrete does not conform, call The Bomanite Company for technical assistance.) 5. Concrete shall not be soft/ dusty due to poor curing or execution of the initial concrete installation. If found to be dusty, apply Bomanite Con-Shield per manufacturer s recommendations. 6. Concrete shall be a minimum temperature of 40 F throughout application and during initial 24-hour cure. 7. If the surface is found to be shiny due to burnished concrete or high-shine type sealers, abrade the surface using a 20-grit sanding disk on a floor machine or shot blast as required. 8. A single base-coat of Micro-Top shall be applied in accordance with the manufacturer s recommendations. 9. After the first coat is dry to the touch, a second coat shall be applied to reach a thickness of 20 mils. 10. A third application of Micro-Top finish coat is optional depending on desired finish and texture. This application is used primarily to achieve a smooth troweled finish. 11. After the initial curing (10-12 hours), a sufficient build of a protective water-based acrylic sealer shall be applied to the surface. 12. On exterior horizontal walking surfaces, a non-skid additive shall be used in the acrylic sealer. B Protection and Maintenance 1. Newly completed surfaces should be protected from water until sealed by the Bomanite Contractor. Water left on the surface before sealing could result in a white film. This will not affect the adhesion or durability and can be cleaned prior to sealing. Acids or solvent materials should not be used over the finished Micro- Top. 2. Regular cleaning and maintenance of interior floors shall be done in accordance with job requirements. This will vary depending on a number of factors including volume and intensity of traffic, UV exposure, geographical location and weather conditions. For instance, interior applications will require a different routine maintenance program than exterior products. Residential applications typically require less cleaning and maintenance than commercial and municipal projects. In

10 large commercial applications, a qualified floor maintenance contractor is recommended for routine cleaning. 3. All Micro-Top installations should be professionally cleaned and resealed periodically by your local Bomanite contractor or a qualified floor maintenance contractor in order to maintain a top-quality appearance. In general, expect the need for professional maintenance to occur every months. Protective maintenance coats of sealer shall be applied periodically to assure the base acrylic is protected and the desired level of gloss is maintained. Exterior Micro-Top surfaces should be resealed annually depending on traffic, especially in freeze-thaw locations. Contact your local Bomanite contractor for the proper maintenance program in your area CURING A. Conform to requirements of Section Concrete Pavement Curing FIELD QUALITY CONTROL A. Testing will be performed under provisions of Division 1 Specifciations B. Compressive Strength Test Specimens: Four test specimens for compressive strength tests will be made in accordance with ASTM C 31 for each 30 cubic yards or less of sidewalk that is placed in one day. Two specimens will be test at 7 days. The remaining two specimens will be tested at 28 days. Specimens will be tested in accordance with ASTM C 39. Minimum compressive strength shall be 3000 pounds per square inch at 7 days and 3500 pounds per square inch at 28 days. C. Yield test for cement content per cubic yard of concrete will be made in accordance with ASTM C 138. If such cement content is found to be less than that specified per cubic yard, reduce batch weights until amount of cement per cubic yard of concrete conforms to requirements. D. If the Contractor places concrete without notifying the laboratory, the Owner will have the concrete tested by means of a core test as specified in ASTM C 42. If the concrete does not meet the specification, the cost of the test will be deducted from payment due the Contractor. E. Sampling of fresh concrete shall be in accordance with ASTM C 172. F. Take slump tests when cylinders are made and when concrete slump appears excessive. G. Concrete shall be acceptable if the average of the two 28-day compression tests is equal to or greater than the minimum 28-day strength specified. H. If neither of the two tests is less than the average of the two tests by more than 10 percent, that entire test shall be considered erratic and not indicative of the concrete strength. Core samples will be required of this concrete

11 I. If any 28-day laboratory test indicates that concrete of low strength has been placed the concrete in question shall be tested by taking cores as directed by the Owner Engineer may direct. At least three representative core shall be taken and tested as specified in ASTM C 42 and the cost deducted from payment due the Contractor REPLACEMENT OF EXISTING SIDEWALKS AND PAVEMENTS DAMAGED DURING CONSTRUCTION A. Replace sidewalks which are removed or damaged during construction with sidewalks of the same thickness, width, and finish to those removed or damaged during construction at no additional cost to the Owner. B. Replace access which are removed or damaged during construction with sidewalks of the same thickness, width, and finish to those removed or damaged during construction at no additional cost to the Owner NONCONFORMING PAVEMENT A. Remove and replace areas of sidewalk that fail compressive strength tests, with concrete of thickness shown on Drawings. B. Non-conforming sidewalk sections shall be replace at no additional cost to the Owner PROTECTION A. Non-architectural sidewalks and pavements. 1. Exclude traffic from pavement for at least 14 days after placement. When construction traffic is permitted, maintain pavement as clean as possible by removing surface stains and spillage of materials as they occur. 2. Replace sidewalks that have cracked, settled, or have otherwise been damaged in accordance with Paragraph 3.01, Replacement. 3. Maintain concrete pavement free of stains, discoloration, dirt, and other foreign material. Sweep concrete pavement not more than two days before date scheduled for Substantial Completion inspections. B. Additional requirements for architecturally finished sidewalks and pavements. 1. Concrete work shall be protected from construction activities and use until architectural finishes have been completed. 2. If concrete becomes covered with dirt and other debris, Contractor shall clean pavement with an approved power washer at not additional cost to the owner

12 3. If concrete is stained with a non-organic material, Contractor shall attempt to clean with a power washer or other non-acidic cleaner. 4. For concrete surfaces that have become dirty prior to staining activities, The Contractor shall NOT clean the surface with an acidic based cleaner or other type of cleaner that may inhibit the application of the final concrete stain. END OF SECTION