A-P-E Process Specifications
A-P-E PROCESS for Encapsulation of Risers, Conductors and Marine Structural Elements
Prepared by MASTER BUILDERS, INC. - Cleveland Ohio, USA
NOTES TO THE SPECIFIER:
The A-P-E Process, as supplied by Master Builders, Inc., Cleveland, Ohio, USA, provides all special equipment, materials and technical information necessary for a contractor to install a state-of-the-art corrosion protective encapsulation on risers or other marine structures, above or below the waterline. The A-P-E Process is intended for field application on deteriorated members, but may be used on new construction as well.
The following guidelines describe each material and equipment item to be used in the process and outline the minimum requirements for surface preparation and installation.
One of the most important features of the A-P-E Process is the specially designed grout handling equipment that batches, mixes and pumps the epoxy encapsulation grout by the plural component method (See Section 4.1). While it is recommended that this method be used whenever possible, there may be instances where mobilizing equipment of this type is impractical. Examples of this might be a single, small diameter riser project where very little encapsulation grout is to be used or work from a platform or vessel that cannot accommodate the following weight and dimensions of the plural component equipment:
Weight: (2,040 kg)
Length: 14 feet (4.3 m)
Width: 6 feet (1.4 m)
Height: 6 feet (1.4 m)
If your project fits this description, please contact Master Builders at the number listed below, for information about smaller, single component pump equipment. If smaller equipment is to be used, a suggested re-wording of (Section 4.1 - Epoxy Grout Handling Unit), follows:
"The epoxy grout to be injected into the outer jackets shall be proportioned, mixed and pumped with equipment expressly designed for that purpose. The equipment shall be capable of delivering mixed grout through hoses and injection ports into the jackets at the rate of 2 GPM or greater."
Should you also wish to specify an in-situ bond strength between the epoxy grout and the riser or other substratum surface, include that value in paragraph 6.5.2. Suggested value for in-situ bond between the epoxy grout and submerged steel surfaces is 50 psi (0.35 MPa).
These guidelines are intended for installations on steel structural elements or risers at temperatures ranging between 55 and 120° degrees F (13-49° C). If your project involves risers handling product at temperatures above 120 degrees F (49° C), please contact Master Builders, Inc., Construction Products Division, 1-800-227-3350, for further information.
The work specified in this section consists of surface preparation of the riser (or other structural element to be encapsulated), placement of a translucent, fiberglass reinforced plastic (FRP) jacket around the riser and injecting a water insensitive epoxy grout into the space between the jacket and the riser. The epoxy grout is batched, mixed and pumped by equipment, expressly designed for that purpose. The approved method for the performance of this work is the A-P-E Process by Master Builders, Inc., Cleveland, Ohio, USA.
The publications listed below form a part of this specification to the extent referenced. The publications are referred to within the text by the basic designation only.
Modified Elcometer Test Method: In-Situ Direct Tension Test of Bond between Encapsulation Materials and The Subsratum They Encapsulate (Copy in Appendix)
- ASTM C 307-83: Tensile Strength of Chemical-Resistant Mortars, Grouts, and Monolithic Surfacings.
- ASTM C 413-83: Absorption of Chemical-Resistant Mortars, Grouts and Monolithic Surfacings.
- ASTM C 531-85: Linear Shrinkage and Coefficient of Thermal Expansion of Chemical-Resistant Mortars, Grouts and Monolithic Surfacings.
- ASTM C 579-82: Compressive Strength of Chemical-Resistant Mortars, Grouts and Monolithic Surfacing.
- ASTM C 882-91: Bond Strength of Epoxy-Resin Systems Used With Concrete By Slant Shear.
- ASTM D 256-88: Impact Resistance of Plastics and Electrical Insulating materials.
- ASTM D 570-81: Water Absorption of Plastics.
- ASTM D 638-89: Tensile Properties of Plastics.
- ASTM D 2583-87: Indentation Hardness of Rigid Plastics by Means of a Barcol Impressor.
- ASTM G 23-89: Operating Light-Exposure Apparatus (Carbon-Arc Type) With and Without Water for Exposure of Nonmetallic Materials.
Manufacturer's Data Sheets. Prior to commencement of the work, the contractor shall submit for approval, manufacturer’s data sheets for each material to be used in the encapsulation work.
Epoxy Grout Handling Equipment. Prior to commencement of the work, the contractor shall submit for approval, the make, model and manufacturer of each piece of equipment he intends to use in the proportioning, mixing and pumping of the epoxy grout. The submittal shall include equipment manuals or photographs of each piece of equipment.
Shop Drawings. Shop drawings, prepared by the contractor, shall be approved by the owner or his engineer prior to commencement of the work. The list of shop drawings shall include, but not necessarily be limited to:
- Top and bottom elevations relative to project datum of each outer jacket to be installed.
- Details and locations of typical longitudinal and transverse joints in the outer jackets, including a description of the join sealing method(s).
- Pattern of fixed and/or adjustable stand-offs for each outer jacket.
- Detail of typical outer jacket bottom seal.
- Location and details of temporary bracing and outer jacket support required during placement and curing of epoxy grout.
- Details of injection ports or other access points into outer jacket to facilitate placement of epoxy grout.
- Details of installation sequence to be used to place the epoxy grout in the space between jacket and pile.
- Detail of final finishing of epoxy grout at top of jacket.
- Details of permanent closure of all injection ports and test locations in the outer jacket to be accomplished after epoxy grout placement is complete.
FRP Outer Jacket.
The outer jackets shall be A-P-E Translucent FRP Jackets, as supplied by Master Builders, Inc., Cleveland, Ohio, USA.
The strength and thickness of the outer jacket shall be as required to provide adequate strength and rigidity to withstand the forces and stresses it may be subjected to during handling, installation and the injection of epoxy grout, but shall not be less than 1/8 inch (3 mm) thick.
The outer jacket shall be translucent to the extent that the progression of epoxy grout inside the jacket during injection can be visually monitored from outside the jacket.
The jacket shall be equipped with 1" NPT injection ports, spaced at intervals not to exceed five (5) feet, along its entire length. The injection ports shall be positioned on alternately opposite sides of the jacket to allow for more even distribution of grout. The injection ports shall be positioned on alternately opposite sides of the jacket to allow for more even distribution of grout. The injection ports shall be of all-polymer construction and be fitted into the jacket wall prior to jacket installation, except in special situation, approved by the engineer, where a port may be added to accommodate an unanticipated jobsite condition.
The jacket shall have a sufficient number of polymer stand-offs, adhered to its inside surface, to maintain a minimum space between the riser and the jacket of ½ inch (12 mm). The use of threaded polymer set screws as adjustable stand-offs, in combination with fixed stand-offs or in lieu of fixed stand-offs, to meet specific project requirements, is permitted. At an adjustable stand-off location, a polyer boss shall be adhered to the inside surface of the jacket to provide adequate thread length to accommodate the set screw.
The outer jacket material, exclusive of stand-offs and set screws, shall possess the following minim physical properties, except as noted in (Italics).
- Ultimate Tensile Strength per ASTM D 638: 10,000 psi (69 MPa)
- IZOD Impact Strength per ASTM D 256: 15 ft - 1 bf/inch (800 J/m) (Notched Sample)
- Barcol Hardness per ASTM D 2583: 30
- Water Absorption per ASTM D 570: 1% (Maximum)
- Ultra-Violet (UV) Stability as demonstrated by Accelerated Weathering Tests per ASTM G 23: Samples of outer jacket subjected to 500 hour exposure in Twin Carbon Arc Weather-ometer (ASTM G 23, Type D) operated at 145 degrees F., shall not exhibit any chipping, flaking or peeling. Said test to be conducted in twenty (20) minute cycles, consisting of seventeen (17 minutes of arc light and three (3) minutes of water spray, throughout the 500 hour test duration.
The outer jacket may be fabricated in a single piece or be made up of sections. Each section shall not contain more than two (2) longitudinal seams. Sections of jacket may be placed one above the other and joined together with transverse seams. All seams in the outer jacket shall meet the following minimum requirements:
- When assembled in accordance with the requirements of this specification, all seams shall have sufficient strength to assure that they will not open or separate when subjected to installation stresses, sea forces and epoxy grout injection pressures.
- The longitudinal seam design shall be of overlapping configuration and shall allow for minor field adjustment to riser size. Transverse seams (if any) shall be of overlapping configuration.
The lower end of each outer jacket shall be provided with a molded upset cavity to properly receive and contain a bottom seal gasket.
The epoxy grout shall be A-P-E Grout, as manufactured by Master Builders, Inc., Cleveland, Ohio, USA. The mixed epoxy grout shall exhibit the following characteristics in the plastic state:
- Viscosity of filled resin and filled curing agent shall be such that it may be pumped without segregation and be injectable in to the space between jacket and riser without causing distortion or rupture of the jacket. The viscosity shall also be such that the blended grout completely fills the space between jacket and riser without voids and be reasonably self leveling, once placed within the jacket.
- The gel time or “Pot Life” of the blended grout shall be suitable for proper placement without voids, and allow sufficient time for reasonable self leveling within the jacket, yet in no case shall exceed 65 minutes after blending at a control temperature of 77 degrees F. (This requirement minimized the possibility of the filler settling out of the liquid components).
- The blended grout shall be uniform in color and not contain any pockets or streaks of the original component colors.
The catalyzed Epoxy Grout, after curing under water, shall possess the following minimum physical properties in the hardened state. Maximum limits are shown as (Maximum).
- 7 Day Compressive Strength per ASTM C 579: 7,000 PSI
- 7 Day Tensile Strength per ASTM C 307: 1,000 PSI
- 7 Day Bond/Shear Strength per ASTM C 882: 150 PSI
- Shrinkage after 7 days’ cure per ASTM C 531: 0.07% (Maximum)
- Water Absorption after 7 days’ cure per ASTM C 413: 0.45% (Maximum)
Marine Epoxy Paste
The epoxy paste used to adhere the outer jacket seams and bottom seal gaskets, shall be HydroCote 3061, as manufactured by Master Builders, Inc., Cleveland, Ohio, USA.
The epoxy paste used to finish the tops of the encapsulations and to seal any in-situ bond test locations, shall by HydroCote 1063-SZ, as manufactured by Master Builders, Inc., Cleveland, Ohio, USA.
Epoxy Hose and Equipment Lubricant.
The material used to lubricate the epoxy contact surfaces of the hoppers, pumps and hoses, shall be Brutem Grout Hose Lubricant, as manufactured by Master Builders, Inc., Cleveland, Ohio, USA.
Epoxy Grout Handling Unit. The epoxy grout to be injected into the outer jackets shall be handled by the plural component method, wherein the epoxy reactive components are kept separate during batching, mixing and pumping, to be blended at the down-stream end of the hoses, just prior to entering the outer jacket. The equipment shall be capable of delivering mixed grout through hoses into the jackets at a rate of 3 GPM or greater. Suitable equipment for this purpose is the A-P-E Grout Handling Unit, available from Master Builders, Inc., Cleveland, Ohio, USA.
Temperature Control Equipment. When ambient and/or water temperatures are expected to fall below 70 degrees F., a source of heated water, such as a diver’s water heater, shall be provided. The heated water shall be directed into water jackets surrounding the epoxy grout hoppers and injection hose(s). This equipment shall be capable of delivering a sufficient amount of heated water to maintain grout viscosity suitable for proper grout placement.
MATERIALS HANDLING AND STORAGE
Handling and storage of encapsulation materials shall strictly conform to the manufacturer’s recommendations. A list of minimum handling and storage requirements follows:
Outer Jackets. Outer jackets shall be shipped in closed containers or covered with tarpaulins to prevent contamination by dirt or road films. Outer jackets shall be stored on end at the jobsite, to minimize distortion and to prevent contamination by foot traffic or wind-blown debris. If storage at project is to exceed 30 days, shaded storage shall be provided.
Epoxy Grout Components.
The silica aggregate component of the epoxy grout shall be properly packaged and labeled to indicate point of origin and manufacturer’s lot number. The aggregate shall be stored to assure that it is thoroughly dry when mixed in the epoxy grout.
All liquid epoxy components to be used in the work shall be delivered to the jobsite in tightly sealed unopened containers, clearly labeled to indicate:
- Name of manufacturer.
- Manufacturer’s product name and component designation.
- Manufacturer’s lot number and “Use before” date.
- ANSI (American National Standards Institute) hazardous material rating and handling precautions.
Epoxy liquid. Epoxy components shall be stored in a covered, well ventilated space. The storage temperature of the liquid components shall not exceed 120 degrees F (49° C) nor be less than 40 degrees F (5° C) at any time after receipt by the contractor. (See 6.3.2., below)
Containers containing liquid epoxy components shall always be sealed and air tight from time of receipt by contractor until entering the proportioning and blending process. When containers are opened for sampling or other purposes and containers remain partially filled, their lids will be tightly closed to prevent contamination by moisture or other substances. Once the seal has been broken on a container, its contents must be used within seven (7) days or removed from the project.
All project personnel handling the epoxy grout or its liquid components shall be properly alerted to the Epoxy Safety Requirements supplied by the manufacturer. A Material Safety Data Sheet (MSDS) shall be supplied with each shipment of liquid epoxy materials.
Surface Preparation of Riser.
Prior to application of the encapsulation process, all riser surfaces shall be thoroughly cleaned of marine growth, oil, grease, mud, rust and any other deleterious material which might prevent proper bonding between the epoxy grout and the riser.
Cleaning shall produce a finished surface over the entire area of the riser to be encapsulated equivalent to SSPC-SP-63 "No. 6 Commercial Blast Cleaning."
In environments where active marine growth occurs, it may be necessary to perform the riser cleaning in two (2) phases. In such environments, the first phase shall consist of removing marine growth, oil, grease, rust, etc., and shall occur not more than seven (7) days prior to the encapsulation. The second phase shall be a final surface preparation, removing all remaining deleterious substances including micro-organisms and shall occur not more than 48 hours prior to the placement of the epoxy grout in the outer jacket.
Outer Jacket Assembly
Only jackets with pre-fitted injection ports are to be used.
The entire inside surface of the jacket shall be lightly grit blasted to remove any bond breaking residue that may be present.
All fixed stand-offs or adjustable stand-off bosses shall be affixed to the jacket in accordance with approved shop drawings.
Jacket assembly and positioning around the riser shall be performed in such a manner as to assure that no damage to stand-offs and/or set screws occurs and that there will be no detrimental movement of the seams while seam adhesive is curing.
Both the longitudinal and transverse seams, if any, shall be sealed with marine epoxy paste described in 3.3.1. above and fastened with 3/16" diameter stainless steel rivets. The spacing between individual rivets shall not exceed 6".
The jacket shall be supported by temporary bracing or other means to assure that it will not move or distort during the epoxy grout placement and curing period and that the minimum annular space of ½ inch between riser and jacket is maintained throughout the entire encapsulation.
Each outer jacket shall be fitted with a bottom seal gasket to prevent the epoxy grout from leaving the bottom of the jacket during the injection process. The gasket shall be fitted into the molded cavity at the lower end of the jacket and adhered in place with marine epoxy paste. Any gasket material used in the bottom seal, shall be contained within the molded cavity and shall not extend up into the jacket above the cavity.
Epoxy Grout Preparation
Proportioning and mixing of the epoxy grout shall be accomplished with equipment as specified in Section 4.1 of this Specification and shall be performed in a suitable work area within hose distance of the riser to be encapsulated.
Proportioning of the silica aggregate and the liquid epoxy components shall be performed in strict accordance with the manufacturer’s recommendations, with particular regard to temperature control. When ambient and/or water temperatures are expected to fall below 70 degrees F. (21 C), the day’s supply of grout filler and liquid components shall be pre-heated to above 80 degrees F. (26 C), but never greater than 120 degrees F. (49 C), prior to being introduced into the grout handling equipment. In no case shall open flame be used in direct contact with the equipment or the epoxy components.
Epoxy Grout Placement (Injection).
Prior to pumping the epoxy grout, the grout hoppers, pumps and hoses shall be thoroughly lubricated with Brutem Grout Hose Lubricant, in strict accordance with the manufacturer’s recommendations. Any excess lubricant shall be expelled and re-captured from the down-stream end of the grout hoses and shall not be injected into the outer jackets.
The premixed, aggregate filled epoxy grout shall be pumped through a hose to the jacket injection ports. When the plural component method of grout handling is used, the separate aggregate filled components shall be pumped through separate hoses to the mixer/blender assembly, where the components are then thoroughly blended and catalyzed just prior to entering the outer jacket.
Grout injection shall begin at the bottom injection port. As the grout appears at the next higher port, and it has been determined that the space between the riser and the jacket is filled to that port, the lower port shall be capped off and the injection begun 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 bypassed. The plug shall be 1" NPT, Schedule 40, PVC, CPVC or Polypropylene.
At the contractors’ option, he may inject a short lift of grout (six inches to 1 foot in height) into the bottom-most port and allow it to cure before proceeding with subsequent lifts. If this practice is used, the jackets shall be fitted with an additional injection port to coincide with the top of the first lift. Subsequent lifts of grout will follow the procedure in 6.4.3., above.
The injection process shall be continuous, except for brief interruptions when the injector is moved from port to port, and the speed of the injection process shall be controlled to prevent entrapment of water or air in the grout cavity being filled.
The maximum permissible voids in the epoxy grout within the jackets shall not exceed 0.01 square foot per one (1) square foot of encapsulation area. Any voids larger than two (2) inches diameter shall be repaired, using an approved method, by the contractor at no expense to the owner.
Final Finishing and Inspection of the Completed Encapsulation.
After the grouting process is completed and the grout has sufficiently cured, all temporary support for the jacket shall be removed.
At intervals and locations directed by the engineer, the bond strength between riser, epoxy grout and jacket shall be tested by the Modified Elcometer Test method. Bond strength after 7 days cure.
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 riser or other substratum surface. To perform a successful test, the bond strength of the adhesive used to attach the dolly and the bond strength at the FRP jacket/epoxy grout interface, must always be greater than the value specified. If either fails before the specified value is reached, the project engineer shall be notified and he may require the test to be re-run at another location.
All test data shall be recorded and reported to the project engineer. If results of these tests indicate bond strengths less than those normal to the process or as specified in 6.5.2. above, the particular encapsulation involved shall be placed in HOLD status for further inspection and final disposition. If any portion of the jacket or epoxy grout is removed from the riser during the test, the affected area shall be repaired by the method shown in the approved shop drawings.
The exposed epoxy grout at the top of each encapsulation shall be finished with the marine epoxy paste described above, using the method shown in the approved shop drawings.
QUALITY ASSURANCE PROGRAM (Optional)
When required by the contract documents, the contractor shall prepare a detailed, project specific, Quality Assurance program, which will be reviewed by the manufacturer and approved by the owner prior to the commencement of work. At a minimum the Quality Assurance program will define areas of responsibility, lines of authority and communication, specific inspections or tests, record keeping and any other activities related to the quality of permanent materials and workmanship that become part of the completed work. At the contractor’s request, the manufacturer will provide guidelines and suggestions pertaining to the riser encapsulation process for inclusion in the contractor's Quality Assurance program.
In special cases, provided for in the contract, the manufacturer will provide trained Quality Control personnel to perform this activity.