SPECIAL SPECIFICATION 7405 Pile Encapsulation

Transcription

1 2004 Specifications CSJ SPECIAL SPECIFICATION 7405 Pile Encapsulation 1. Description. Prepare the pile surface and place a translucent, fiberglass reinforced plastic (FRP) jacket around the pile. Inject a water insensitive epoxy grout into the space between the jacket and the pile or use an approved equivalent method. 2. Materials. Before work commences, submit for approval, Manufacturer s Data Sheets for each material to be used. A. FRP Outer Jacket. Provide A-P-E translucent and semi transparent FRP outer jackets by Master Builders, Inc. or an approved equivalent. Approved equivalents, must meet the following requirements: 1. Marine grade laminate of fiberglass reinforced plastic (FRP), constructed of layers of woven roving and mat. Construction by the spray-up process, or chopper gun, is not acceptable. Glass content will meet the strength requirements found in Section 2.A. herein, with a minimum 30% of the laminate. Integrally bind an Ultra Violet (UV) screening ingredient within the polyester matrix. 2. Minimum 1/8 in. thickness with the strength to withstand the forces and stresses during handling, installation, and the injection of epoxy grout. 3. Translucent enough to visibly monitor the progression of epoxy grout from outside the jacket during injection. 4. Equipped with 1 in. NPT injection ports, spaced at maximum intervals of 5 ft., along its entire length. Position the injection ports on alternately opposite sides of the jacket to allow for even distribution of grout. Before installing the jacket, fit the polymer-constructed injection ports in the jacket wall. With approval, add ports to accommodate unanticipated jobsite conditions. 5. Equipped with a sufficient number of polymer stand-offs, adhered to its inside surface, to maintain a minimum space of 3/8 in. between the pile and the jacket When loss of pile section exists, use adjustable stand-offs to keep the outer jacket in proper alignment with the pile. At an adjustable stand-off location, adhere the polymer boss to the inside surface of the jacket to provide adequate thread length to accommodate the adjustable polymer screw. 6. Possess the following minimum physical properties, except as noted in (italics), exclusive of the polymer stand-offs and injection ports. a. Ultimate Tensile Strength per ASTM D , Tensile Properties of Plastics : 15,000 psi

2 b. IZOD Impact Strength per ASTM D , Impact Resistance of Plastics and Electrical Insulating Materials : 20 ft-lbf/in. (Notched Sample) c. Barcol Hardness per ASTM D , Indention Hardness of Rigid Plastics by means of Barcol Impressor : 35 d. Water Absorption per ASTM D , Water Absorption of Plastics : 1% (Maximum) e. Ultra-Violet (UV) Stability per ASTM G-23-89, Operating Light Exposure Apparatus (Carbon-Arc Type) with and Without Water for Exposure of Nonmetallic Materials : Samples of outer jacket subjected to 500 hour exposure in Twin Carbon Arc Weather-ometer (ASTM G-23, Type D) operated at 145ºF, shall not exhibit any chipping, flaking or peeling. Conduct tests in 20 min. cycles, consisting of 17 min. of arc light and 3 min. of water spray, throughout the 500 hour test duration. 7. Sections fabricated not contain a maximum of 2 longitudinal joints. Stack the sections one above the other and join together with transverse joints. Joints will meet the following minimum requirements: a. Provide sufficient strength to remain closed and not open or separate when subjected to installation stresses, sea forces and epoxy grout injection pressures. b. Design shall be of overlapping configuration and allow for minor field adjustment to pile size. Ensure a minimum 3/8 in. annulus is maintained between jacket and pile. c. Transverse joints (if any) will be of overlapping configuration. 8. Provide a molded upset cavity to the lower end of the jacket to properly receive and contain a bottom seal gasket. B. Epoxy Grout. Use A-P-E Epoxy Grout or approved equivalent, as described. Approved equivalents must meet the following requirements: 1. Manufactured, prepackaged, solvent-free, underwater curing, three component product, consisting of epoxy resin (component A), epoxy hardener (component B), and graded dry silica aggregate filler (component C). The ratio of the epoxy components A and B (collectively called the binder) is 1:1 by volume. To minimize error in field proportioning and to assist in evaluating thoroughness of mixing, supply A and B components of sharply contrasting colors. Proportion the grout to meet the handling and placement requirements of this specification. Do not exceed the ratio of filler to binder 3.5:1, by weight. 2. Exhibit the following characteristics in the plastic state: a. Viscosity of filled resin and filled curing agent are pumped without segregation and be injected into the space between the jacket and the pile without causing distortion or rupture of the jacket. The viscosity must be such that the blended

3 grout completely fills the space between jacket and pile without voids and be reasonably self-leveling, once placed within the jacket. b. The gel time or "Pot Life" of the blended grout must be suitable for proper placement without voids, and allow sufficient time for reasonable self leveling within the jacket, yet not exceed 65 min. after blending at a control temperature of 77ºF. (This requirement minimizes the possibility of the filler settling out of the liquid components.) c. The blended grout is uniform in color and contains no pockets or streaks of the original component colors. 3. The catalyzed Epoxy Grout, after curing under water, must possess the following minimum physical properties in the hardened state. Maximum limits are shown in (Italics). a. 7 Day Compressive Strength per ASTM C , Compressive Strength of Chemical-Resistant Mortars, Grouts and Monolithic Surfacing : 7,000 psi b. 7 day Tensile Strength per ASTM C Tensile Strength of Chemical Resistant Mortars, Grouts and Monolithic Surfacings : 1,000 psi c. 7 day Bond/Shear Strength per ASTM C : Bond Strength of Epoxy Resin Systems Used With Concrete By Slant Shear : 150 psi d. Shrinkage after 7 day's cure per ASTM C Linear Shrinkage and Coefficient of Thermal Expansion of Chemical Resistant Mortars, Grouts and Monolithic Surfacings : 0.07% (Maximum) e. Water Absorption after 7 day's cure per ASTM C Absorption of Chemical Resistant Mortars, Grouts and Monolithic Surfacings : 0.45% (Maximum) C. Marine Epoxy Pastes. 1. Use HydroCote 3061-I or approved equivalent to adhere the outer jacket seams and bottom seal gaskets. To be approved as equivalent, the epoxy paste must be a two component epoxy compound, capable of being applied underwater. The ratio of resin component to hardener component is 1:1 by volume. To assist in evaluating the thoroughness of job site mixing, each component must be of sharply contrasting color. 2. Use the HydroCote 1063 or approved equivalent to finish the tops of the encapsulations and to seal any in-situ bond test locations. To be approved as an equivalent, the epoxy paste must be non sag, two component epoxy compound, capable of being applied underwater. The ratio of resin component to hardener component shall be 1:1 by volume. To assist in evaluating the thoroughness of jobsite mixing, each component must be of sharply contrasting color

4 D. Epoxy Grout Hose Lubricant. 1. Use Brutem Lubricant or approved equivalent for the pumping equipment and hoses. To be approved as an equivalent, the lubricant must be an epoxy diluent, compatible with the chemistry of the epoxy grout used. E. Materials Handling and Storage. Conform to the Manufacturer s recommendations for handling and storage. As a minimum adhere to the following: 1. Outer Jackets. Ship outer jackets in closed containers or cover with tarpaulins to prevent contamination by dirt or road films. Store the outer jackets at the jobsite to minimize distortion and to prevent contamination by foot traffic and blown debris. Provide shaded storage if the project is expected to exceed 30 days. 2. Epoxy Grout Components. a. Package and label the silica aggregate component of the epoxy grout to indicate point of origin and manufacturer's lot number. Store the aggregate to assure that it is thoroughly dry when mixed in the epoxy grout. b. Deliver all liquid epoxy components to the jobsite in tightly sealed, unopened containers, clearly labeled to indicate: (1) Name of manufacturer. (2) Manufacturer s product name and component designation. (3) Manufacturer s lot number and "Use before" date. (4) ANSI (American National Standards Institute) hazardous material rating and handling precautions c. Store the liquid epoxy components in a covered, well ventilated space. Do not exceed a maximum storage temperature of 120ºF and a minimum temperature of 40ºF at any time after receipt. (See Section 4.(D.)(2.), below) d. Seal liquid epoxy components in air tight containers from time of receipt by contractor until entering the proportioning and blending process. Tightly close container lids when opened for sampling or other purposes. Once a container seal has been broken, its contents must be used within 7 days or removed from the project. e. Alert all project personnel handling the epoxy grout or its liquid components of the Epoxy Safety Requirements supplied by the manufacturer. Supply a Material Safety Data Sheet (MSDS) with each shipment of liquid epoxy materials. 3. Equipment. Before work commences, provide the make and model of epoxy grout handling equipment for use in proportioning, pumping, and mixing. Include manufacturer s equipment manuals or photographs of equipment

5 A. Proportion, mix, and pump epoxy grout with equipment expressly designed for that purpose. Provide equipment capable of delivering mixed grout into the jackets at the rate of 2 gpm or greater. Acceptable equipment for this purpose is the A-P-E Single- Component ( Hot-Pot ) Grout Handling Unit, available from Spray-Quip, Inc., Houston Texas. B. Temperature Control Equipment. Provide a source of heated water, such as a diver s water heater, when ambient or water temperatures are expected to fall below 70ºF. Direct the heated water into water jackets surrounding the epoxy grout hoppers and injection hose(s). Use equipment capable of delivering a sufficient amount of heated water to maintain grout viscosity suitable for proper grout placement. 4. Work Methods. A. Submittals. Before work commences, submit the following for approval: 1. Top and bottom elevations relative to project datum of each outer jacket to be installed. 2. Details and locations of typical longitudinal and transverse joints in the outer jackets, including a description of the joint sealing methods. 3. Details of fixed or adjustable stand-offs and their location on the outer jackets. 4. Detail of typical outer jacket bottom seal. 5. Location and details of temporary bracing and outer jacket support required during placement and curing of epoxy grout. 6. Details of installation sequence to be used to place the epoxy grout in the space between jacket and pile. 7. Detail of final finishing of epoxy grout at the top of the encapsulation. 8. Details of permanent closure of all injection ports and test locations in the outer jacket to be accomplished after epoxy grout placement is complete. B. Pile Cleaning. 1. Before the application process, thoroughly cleans all pile surfaces shall be thoroughly cleaned of marine growth, oil, grease, mud, rust, broken concrete, micro-organisms and any other deleterious material which might prevent proper bonding between the epoxy grout and the pile. Accomplish pile cleaning by grit blasting or by divers using powered rotary abraders. Any method that produces the quality of cleaning necessary to meet the bond requirements of this specification may be considered. 2. Produce a finished surface over the entire area to be encapsulated which results in a bond strength between epoxy grout and the pile surface, greater than the minimum required in Section 4.F

6 3. When necessary, perform the pile cleaning in 2 phases where active marine growth occurs. In the first phase, a maximum of 7 days before the encapsulation, remove marine growth, oil, grease, rust, and broken concrete, etc. In the second phase, a maximum of 48 hrs before placement of epoxy grout in the outer pile jacket, perform a final surface preparation, removing all remaining deleterious substances including micro-organisms. C. Outer Jacket Assembly. 1. Only jackets with pre-fitted injection ports (by the Contractor) are to be used. 2. Lightly grit blast the entire inside surface of the jacket to remove any bond breaking residue that may be present. 3. Affix all fixed stand-offs or adjustable stand-off bosses to the jacket by the Contractor in accordance with approved shop drawings. Maximum spacing between fixed stand-offs shall be 18 in. in the longitudinal direction and 12 in. in the transverse direction. 4. Place the jacket assembly and position it around the pile in such a manner as to assure that no damage to stand-offs and set screws occur. Ensure there will be no detrimental movement of the joints while joint adhesive is curing. Place the jacket in the splash zone, within 5 ft. ± of the waterline, or at the mudline. The placement of the jacket is to be determined by the location of the affected pile and in accordance with the contract drawings. 5. Seal the longitudinal and transverse seams, if any, with marine epoxy paste as described in Section 2.C.1. Fastened with 3/16 in. diameter stainless steel rivets. Do not exceed 5 in. spacing between individual fasteners. 6. Support the jacket by temporary bracing or other means. Assure that it will not move during the placement of epoxy grout and curing period. Maintain a minimum annular space of 3/8 in. between pile and jacket throughout the entire encapsulation. 7. Install a gasket to prevent the epoxy grout from leaving the bottom of the jacket during the injection process. Fit the gasket into the molded cavity at the lower end of the jacket and adhere in place with marine epoxy paste. Contain any gasket material used in the bottom seal within the molded cavity. Prevent any gasket material from extending up into the jacket above the cavity. D. Epoxy Grout Preparation. 1. Use equipment designed for proportioning and mixing epoxy grout. Perform the work in a suitable work area within hose distance of the piles to be encapsulated. 2. Perform proportioning of the silica aggregate and the liquid epoxy components in strict accordance with the manufacturer's recommendations, with particular regard to temperature control. When ambient and water temperatures are expected to fall below 70ºF, the day's supply of grout filler and liquid components shall he preheated to above 80ºF, to a maximum of 120ºF, before being introduced into the

7 grout handling equipment. Use no open flame in direct contact with the equipment or the epoxy components. E. Epoxy Grout Placement (Injection). 1. Before the injection process begins, place at least 2 gal. of an approved grout hose lubricant in each grout hopper. Pump the lubricant through the entire system to coat all wetted surfaces of the hoppers, pumps, and hoses. When the lubricant level has reached the bottom of the hoppers, it may be immediately followed by the epoxy grout and the remaining lubricant "chased" out of the hoses. Collect any lubricant that is not intermixed with the epoxy grout at the downstream end of the hoses for re-use. 2. Pump the premixed aggregate filled epoxy through hoses to the jacket injection ports. If the plural component method of grout handling is used, pump the separate aggregate filled components through separate hoses to the mixer/blender assembly. Thoroughly blend and catalyze the components before entering the pile jacket. 3. Begin grout injection at the bottom injection port. As the grout appears at the next higher port, and it has been determined that the space between the pile and the jacket is filled to that port, cap of the lower port and begin the injection at the next higher port where the grout appeared. This process is repeated from port to port until the grout reaches the top of the jacket. NOTE: If project experience indicates that the grout can be injected from a lower port, past the next higher port or ports, without difficulty or undo stress on the jacket, the higher port or ports may be plugged and by-passed. Use plugs 1 in. NPT, Schedule 40, PVC, CPVC or Polypropylene. 4. Alternatively, inject a short lift of grout (6 in. to 1 ft. in height) into the bottommost port and allow it to cure before proceeding with subsequent lifts. If this practice is used, fit the jackets with an additional injection port to coincide with the top of the first lift. Subsequent lifts of grout will follow the procedure in Section 4.F The injection process is continuous, except for brief interruptions when the injector is moved from port to port. Control the speed of the injection process to prevent entrapment of water or air in the grout cavity being filled. 6. The maximum permissible voids in the epoxy grout within the jackets will not exceed 0.01 sq. ft. per 1 sq. ft. of encapsulation area. Repair any voids larger than 2 in. in diameter using an approved method, at no additional expense. F. Final Finishing and Inspection of the Completed Encapsulation. 1. Remove all temporary supports for the jacket after the grouting process is completed and the grout has sufficiently cured. 2. At intervals and locations directed, test the bond strength between the pile or other encapsulated members and the encapsulation materials by the Modified Elcometer Test method. The minimum bond strength is 90 psi after 7 days

8 (The Modified Elcometer Test method is described in the APPENDIX, Section 8.1.) SPECIAL NOTE: In the Modified Elcometer test method, the tensile load is transferred from the test dolly to the FRP jacket, then from the FRP jacket to the epoxy grout and finally, from the epoxy grout to the pile or other substratum surface. The bond strength of the adhesive used to attach the dolly and the bond strength at the FRP jacket to epoxy grout interface, must always be greater than the minimum value specified. If either fails before the minimum value is reached, notify the department. The test may have to be re-run at another location. 3. Record and report all test data. If results of these tests indicate bond strengths less than those normal to the process or as specified in Section 4.F.2. above, place the particular encapsulation involved in HOLD status for further inspection and final disposition. If any portion of the jacket or epoxy grout is removed from the pile during the test, repair the affected area by the method shown in the approved shop drawings. 4. Finish the exposed epoxy grout at the top of each encapsulation with the marine epoxy paste described in Section 2.C.2. above, using the method shown in the approved shop drawings. 5. Measurement. This Item will be measured by the foot as measured along the length of the pile. 6. Payment. The work performed and the materials furnished in accordance with this Item and measured under Measurement will be paid for at the unit price bid for Pile Encapsulation. This price is full compensation for furnishing all materials, tools, labor, equipment and incidentals