36--Contract awarded to TDB Concrete in the amount of $22223.00

General Requirements 1. SCOPE: Furnish all labor, equipment, supplies, permits and material to remove 12 inches of rock, road base and soil, place and compact Class 6 road base from Government Stockpile to provide a 6 inch compacted base for the concrete, place 6 inches of concrete with #4 reinforcement bar at 18 inches on center as described in the specifications and shown on the attached sheets. A potable water source is available on the north side of the maintenance building. 2. Duration: All work shall be completed within 60 calendar days of receipt of the Notice to Proceed. 3. Safety Manual: The U.S. Army Corps of Engineers safety manual (EM 385-1-1) was revised as of September 15, 2008 and must be followed at all times. The current EM 385-1-1 can be found on the internet at: http://publications.usace.army.mil/publications/eng-manuals/EM_385-1-1_languages/EM_385-1-1_English_2008/toc.html 4. Site Specific Work Plan: A site specific work plan shall include a description of the work to be performed, the size of the crew, the equipment which will be used on site, an Accident Prevention Plan as shown in Appendix A of the EM 385-1-1, an Activity Hazard Analysis as shown on pages 9 - 11 of the EM 385-1-1 must be submitted by the contractor and approved by the USACE before work begins. 5. Personal Protective Equipment: A minimum of short-sleeve shirt, long pants, leather work boots w/safety toe, and hard hat shall be worn at all times as per EM 385-1-1, Appendix A, pages A-9 and A-10, Paragraphs 11.k.(1)-(8). Other Personal Protective Equipment, such as eye protection, hearing protection, gloves, shall be properly used as needed and as identified in the site specific work plan. 6. Site Visit: Site visit will be on 26 July 2012 at 1:00 pm. The site visit is highly recommended, but not mandatory. Contact Carl Voss at +1 (555) 000-0000 to confirm attendance. 7. Warranty: All work and materials furnished under this contract shall be guaranteed for a minimum of one (1) year from the date of acceptance thereof, either for beneficial use or final acceptance, whichever is earlier, against defective materials, design, and workmanship. Upon receipt of notice from the Government of failure of any of the guaranteed equipment during the guarantee period, new replacement parts shall be furnished and installed promptly by the Contractor at no additional cost to the Government. The Contractor shall also obtain and deliver to the Contracting Officer any warranties of work and materials which the subcontractors, manufacturers, or suppliers would give normal commercial practice. 8. Protection of Existing Facility and Works: The Contractor shall be responsible for the protection of the work area from damage and upon completion of the work shall leave existing works in a condition equal to that which existed when work started. 9. Clean up: Daily clean up of all debris and waste material is required. 10. First Aid and Medical: First aid kits shall be made available on the job site by the contractor. All emergency numbers (doctors, hospital, ambulance, fire department) shall be readily available. 11. Sanitation Facilities: Toilet facilities and drinking water are not available on site. 12. Accident Reporting: All accidents (employee injuries, vehicle, building, or equipment property damage) regardless of their severity shall be reported to the on site government representative. 13. Submittals: The following items shall be submitted using ENG Form 4025. An electronic copy can be found at: http://publications.usace.army.mil/publications/forms/ENG_FORM_4025_Mar_1995.pdf The 2nd page of the form has the instructions for the form. The submittals shall be approved by the U.S. Army Corps of Engineers before work on site can begin. 1. Site Specific Work Plan (see paragraph 4) 2. Bill of Materials (see paragraph 14) a. Name of ready mixed concrete plant b. Type of cement, admixtures, if any, and brand name. c. Reinforcement bar information. d. Cure and Seal information. 3. Tests (Paragraph 14.1) 4. Product and Delivery Submittals (14.2) SCOPE OF CONTRACT Concrete Slab in Pole Building 14. Grade and Level with proper drainage: The approximate area of the concrete slab will be 36 feet wide by 43 feet long. Remove and stockpile current surface of 2 inches of " inch crushed rock on top of 4 inches of road base. Remove 6 inches of soil from the work area for the concrete slab and stockpile the soil in the designated area to the west of the Government Stockpiles of rock, as directed by the COR. Place and compact Class 5 road base from the Government Stockpile to provide a 6 inch base for the concrete slab. Install 6 inch thick concrete slab with 4000-PSI concrete, #4 reinforcement bars at 18 inches on center, broom finish, then apply a cure and seal. The grade and slope of the concrete shall be such to direct water out of the front of the building and away from the interior walls, as directed by the COR. All of the site work shall be in a workman like manner and meet the following specifications: 14.1. QUALITY CONTROL AND ASSURANCE A. Testing: 1. Sampling and testing will be performed by independent testing laboratories and paid for by Contractor in accordance with Section 0145500 for quality control. 2. Perform slump tests (ASTM C143), and air-entrainment tests (ASTM C231) daily for each class of concrete poured. 3. Perform compressive strength tests (ASTM C31 and C39) for each of the following conditions for each class of concrete: a. Each day's pour. b. Each change of source. c. Each 50 cu yd of concrete poured. d. When temperatures are below expected to fall below 45 degrees Fahrenheit within 48 hours after concrete is placed, make 2 additional cylinders and field cure test, one at 7 days and the other at 28 days. 4. Three cylinders will be cast for each compressive strength test. The cylinders will be tested according to the following schedule: a. 1 at 7 days b. 1 at 14 days c. 1 at 28 days B. Owner shall provide for quality assurance testing as deemed necessary. C. Tolerances: 1. Maintain formwork alignment during and after placing of concrete, in accordance with permissible tolerance limits set forth in ACI 347. 2. Concrete shall be within 1/4 inch of 10-ft. straightedge in all directions. Deviations from elevation indicated shall not exceed 1/4 inch. D. Reference Standards: 1. American Concrete Institute (ACI): a. ACI SP-66 - ACI Detailing Manual. b. ACI 304-73 - Recommended Practice for Measuring, Mixing, Transporting, and Placing Concrete. c. ACI 305R-77 - Hot Weather Concreting. d. ACI 306R-88 - Cold Weather Concreting. e. ACI 318-83 - Building Code Requirements for Reinforced Concrete. f. ACI 347-78 - Recommended Practice for Concrete Formwork. g. ACI Committee 308 - "Standard Practice of Curing Concrete." 2. American Society for Testing and Materials (ASTM): a. ASTM A185 - Welded Steel Wire Fabric for Concrete Reinforcement. b. ASTM A615 - Deformed and Plain Billet-Steel Bars for Concrete reinforcement. c. ASTM C31-83 - Making and Curing Concrete Test Specimens in Field. d. ASTM C33-82 - Specification for Concrete Aggregates. e. ASTM C39-83A - Test Method for Compressive Strength of Cylindrical Concrete Specimens. f. ASTM C94-83 - Specification for Ready Mixed Concrete. g. ASTM C143-78 - Test Method for Slump of Portland Cement Concrete. h. ASTM C150-83A - Specification for Portland Cement. I. ASTM C231-82 - Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method. j. ASTM C260-77 - Specification for Air-Entraining Admixtures for Concrete. k. ASTM C171 - Specification for Sheet Materials for Curing Concrete. l. ASTM C494-82 - Specification for Chemical Admixtures for Concrete. 3. American Association of State Highway and Transportation Officials: a. AASHTO M182 - Specification for Burlap Cloth Made from Jute and Kenaf for Curing Concrete. 14.2. PRODUCT AND DELIVERY SUBMITTALS A. Statement by ready mix supplier giving source and material certificates, and proportions by weight of cement, fine and course aggregates, and admixtures. B. Provide with each load of concrete delivered, duplicate delivery tickets one for Contractor and one for Engineer with following information: 1. Date and serial number of ticket. 2. Name of ready mixed concrete plant, operator, and job location. 3. Type of cement, admixtures, if any, and brand name. 4. Cement content, in bags/cu yd of concrete and pounds per each load, and mix design including pounds of each aggregate per each load. 5. Truck number, time loaded, and name of dispatcher. 6. Amount of concrete in load, in cu yd, delivered. 7. Maximum size aggregate. 8. Gallons of water added at batch plant and at job, if any, and slump of concrete after water was added. 9. Temperature of concrete at delivery. 10. Number of revolutions of mixer after addition of water. D. Submit in accordance with Paragraph 12. 14.3. JOB CONDITIONS A. Hot Weather: 1. Comply with ACI 305R. 2. Concrete temperature shall not exceed 90oF. At air temperatures of 80oF or above, keep concrete as cool as possible during placement and curing. Cool forms by water wash. B. Cold Weather: 1. Comply with ACI 306R. 2. Temperature of reinforcement, forms, fillers, and other materials in contact with concrete at time of placement shall not be less than 35oF. Preheat if temperature is below 35oF. 3. Maintain air and forms in contact with concrete sections having minimum dimension less than 12 inches at temperature above 32oF for remainder of specified curing period. 4. Maintain air and forms in contact with concrete in more massive sections at temperature above 40oF for at least first 3 days and at temperature above 32oF for remainder of specified curing period. PART 2 PRODUCT 15.1. MATERIALS A. Portland Cement: 1. ASTM C150, Type IIIA, modified with not less than 5% tri-calcium aluminate. 2. When aggregates are determined to be deleteriously reactive, as defined by Appendix XI of ASTM C33, alkali content of cement defined by Table 1A of ASTM C150 shall not exceed 0.60%. B. Aggregates: 1. ASTM C33, free of foreign materials. 2. Fine Aggregate: Natural sand. 3. Course Aggregate: Crushed stone, crushed gravel or gravel. Size 67 (3/4 inch maximum). 4. Potential reactivity of aggregates shall be determined in accordance with Appendix XI of ASTM C33. C. Admixtures for Concrete: 1. Air-Entraining: ASTM C260. 2. Chemical Admixtures: Optional, ASTM C494. a. Water Reducing: Type A. D. Fiber reinforcement shall be added to all concrete flatwork and curbs. Fiber reinforcement shall consist of synthetic fibers engineered and designed for secondary reinforcement of concrete slabs and shall comply with ASTM C 1116, Type III E. Water. 1. Potable water conforming to ASTM C94. F. Curing Materials: 1. Burlap cloth made from jute or kenaf, AASHTO M182. 2. Sheet materials for curing concrete, ASTM C171. 3. Liquid membrane type, conforming to ASTM C309, Type 1 a. Apply in accordance to manufacturers instructions in two coats. Minimum rates for first coat is 400 square feet per gallon, and 600 square feet per gallon for second coat. 4. For colored concrete use clear waterborne membrane-forming curing compound conforming to ASTM C 309, Type I, Class B. Provide material that has a maximum volatile organic compound rating of 350 g/L. G. Epoxy Bonding Compound: Joining new to previously placed concrete and embedded anchor installation. 1. ASTM C881-78, Type II, Curing, temperature requirements (Class), and viscosity (Grade) shall be determined by supplier and contractor after project requirements have been established. 2. Suppliers: a. Sika Chemical Company. b. W.R. Grace and Company. c. Adhesive Technology Inc. d. Or an approved substitute. H. Expansion Joint Material. 1. Expansion joint material shall be performed joint filler and shall conform to ASTM D1751 or D1752. I. Joint Sealant. 1. Single component self-leveling urethane. Vulken 45 by Mameco Intl. or approved equal. 15.2. CONCRETE MIX DESIGN A. Concrete Mix: Measure and combine cement, aggregates, water, and admixtures in accordance with ASTM C94. 1. Project Concrete: a. Minimum Cement Content: 6 bags/cu. yd. b. Minimum 28 Day Strength: 4,000 psi (3 days 3,000 psi). c. Air Content: 6% +/- 1%. d. Maximum Slump: 3 1/2 in. e. Maximum Water-Cement Ratio for Air-Entrained: 0.45 +/- 0.05. 15.3. MIXING AND DELIVERY A. Furnish and deliver concrete in conformance with ASTM C94. B. Deliver and complete discharge within 1-1/2 hrs of commencing mixing or before 300 revolutions of drum or blades, whichever comes first. This includes revolutions required by transit mixed trucks. Limitations may be waived by Engineer if concrete is of such slump after 1-1/2 hrs or 300 revolution limit has been reached it can be placed without addition of water. C. Do not add water on job, unless authorized by Engineer. If water is added, additional mixing of 30 drum revolutions is required each time water is added. Water addition will not be permitted after placement of one cubic yard of concrete from any load. PART 3 EXECUTION 16.1. SUBGRADE PREPARATION A. Subgrade and/or Bedding: Compacted and free of frost or snow. If placement is allowed at temperatures below freezing, provide temporary heat and protection as required to remove frost from subgrade and raise temperature of adjacent concrete above 35oF. B. Provide mud slabs where necessary and when required by Engineer to obtain dry and stable working platform for placement of slabs on grade. C. Where vapor barrier is not specified, at Contractor's option, provide vapor barrier or soak subgrade evening before placement and sprinkle ahead of placement of concrete. D. Remove standing water, ice, mud, and foreign matter before concrete is deposited. Concrete shall not be placed against frozen subgrade which has been heated locally to remove ice deposits. 16.2. FORMS A. Workmanship: Formwork shall prevent leakage of mortar. Removal of wall ties shall leave holes clean cut and without appreciable spalling at face of concrete. B. Materials: 1. Unless specified otherwise, type of forms used is Contractor's option. Contractor may use metal, plywood, presswood form liners or plastic surfaced plywood. 2. Use approved commercially manufactured devices for form ties. Arrange ties so when forms are removed, no metal will be within 3/4 in. of formed face of concrete. C. Do not disturb forms until concrete has adequately cured. D. Design of forming system shall be the responsibility of Contractor. E. All exposed corners shall receive 3/4 in. chamfer. 16.3. JOINTS A. Joints not shown on Drawings shall be subject to approval by Engineer. 1. Tooled joints. a. Transverse joints shall be located at intervals of 10 feet in curbs, gutters, cross pans and general slab areas. 2. Expansion joints. a. Expansion joint material shall be installed between new structure slabs and existing concrete slabs or as shown on plans. Expansion joint material must be set vertical and the top edge flush with the finished surface. Where shown on plans joint sealant will be used and installed in accordance to manufacturer instructions. 16.4. CONCRETE PLACEMENT A. Except as modified herein, ACI 304 - Chapter IV, shall constitute requirements of the Specification. B. Care shall be taken to avoid damage to reinforcing and ensure its accurate positioning after concrete has been placed. C. Do not spread concrete with vibrators. D. When placing of concrete is temporarily halted or delayed, provide construction joints as shown on drawings and/or as specified herein. E. Place concrete with aid of internal mechanical vibrator equipment capable of 7,000 impulses/min. Transmit vibration directly to concrete. Duration of vibration at any location shall be adequate to produce thorough consolidation and also to cause maximum amount of air bubbles to migrate to top of pour. F. Set embedded items such as bolts, anchors, and piping, in concrete as required by manufacturer of equipment used. Verify location with equipment manufacturers. G. Place items constructed of dissimilar metals to avoid physical contact with reinforcing. Secure item and reinforcing to ensure they will not shift and come into contact during pouring. Contact between reinforcing and any other metal, other than bare, coated or plated carbon steel or stainless steel will not be permitted, unless specifically approved by Engineer. H. Install epoxy adhesives, bonding agents, anchor bolt setting grouts, and mortars as per the manufacturers published procedures and recommendations and as directed by the Engineer. 16.5. FINISHING UNFORMED CONCRETE A. After screening and consolidating concrete, do not work surface until ready for floating. Begin floating when surface water has disappeared, or when concrete has stiffened sufficiently to permit operation of floats. Check and level surface plane to required tolerance. Cut down high spots and fill low spots. Immediately after leveling, refloat surface to a uniform, smooth, granular texture. After the moisture sheen has disappeared from floated surface and concrete has hardened sufficiently to prevent drawing moisture and fine material to the surface, it shall be broomed to a uniform granular finish. 1. All areas will have a broomed finish. 16.6. FINISHING FORMED CONCRETE A. Ordinary Finish: Finish resulting directly from formwork for surfaces which will be hidden from view by earth, submergence in water or subsequent construction. 1. Patch honeycombing, stone pockets, form tie holes, spalls, and other irregularities. B. Smooth Finish: Concrete surfaces permanently exposed to view or in contact with water. 1. Patch honeycombing, stone pockets, form ties, spalls, and other irregularities. 2. Grind joint marks and fins smooth with flat wall surface. Remove oil stains and rinse surface. 16.7. PROTECTION AND CURING A. Protect concrete from cold weather in accordance with ACI 306 R-88. B. Protect against moisture loss (curing) in accordance with "Standard Practice of Curing Concrete," reported by ACI Committee 308 using approved method and materials. Immediately after placing and finishing, concrete surfaces not covered by forms shall be protected from loss of surface moisture for a cumulative total of not less than 7 days above 50o F. These 7 days need not be consecutive. For high early strength portland cement, the 7 days may be reduced to 4 days. Surfaces from which forms are removed before the curing period has elapsed shall be protected as specified for surfaces not covered by forms. Curing shall be accomplished by using materials specified herein under 2.1.F and as follows: 1. By water curing: Use mechanical sprinklers or other approved method which will keep the surface continually wet, or apply burlap or 1 inch of sand and keep continuously saturated. Water curing shall not be employed if the concrete is to be subjected to near freezing or sub-freezing temperatures without adequate protection. 2. By water resistant covering: Apply one of the specified paper or sheeting materials to cover the entire surface, lap 4 inches at joints and seal with tape. C. Formed surfaces may be cured by leaving forms in-place. Spray surface of forms left in-place during curing period as frequently as drying conditions may require to keep concrete surfaces moist. For vertical surfaces, apply water to run down on inside of forms, if necessary to keep concrete wet only after concrete has set. Keep water on forms from freezing. D. Apply curing compounds/sealers in accordance to manufacturer's instructions. E. Protect from damaging mechanical disturbances, particularly load stresses, heavy shock, and excessive vibration. F. Protect finished concrete surfaces from damage caused by construction equipment, materials or methods, and rain or running water. G. Do not load self-supporting structures in such way as to overstress concrete. 16.8. DEFECTIVE WORK A. All defective work as determined by the Project Manager will be replaced at no cost to the State. B. Defective work shall include, but not be limited to the following: 1. Cracking. 2. Scratches or gouges in concrete. 3. Poorly finished or tooled concrete. 4. Spalding. 5. Forming problems, bulges, sags, dips, etc. 6. Settlement. * * * END OF SECTION * * *