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STRUCTURAL STRENGTHENING
MFORCE CF-20J / CF-30J
High Performance Embrace Reinforcement Carbon Fiber Sheet for Structural Strengthening
SCOPE
This section covers the standard requirements structural strengthening using MFORCE CF-20J / CF-30J.
MFORCE CF-20J / CF-30J sheet is a carbon fiber uni-directional sheet for structural reinforcement, manual wrap lamination and tensile strength reinforcement to structural members.
MFORCE CF-20J / CF-30J sheet is a carbon fiber uni-directional sheet for structural reinforcement, manual wrap lamination and tensile strength reinforcement to structural members.
1. Surface Preparation Works
1.1 Before application of the MForce CF Sheets, the quality of the substrate has to be checked. The tensile strength has to be tested with pull-off bond test. For load to be transferred from the carbon sheet into the bearing substrate, a tensile surface of at least 1 N/mm2 is required.
1.2 The surface to receive composite shall be clean and free from fins, sharp edges and protrusions which may cause voids behind the layer of the installed wraps that may cause damage on the fiber.
1.3 Cement laitance, dust, dirt, oil, grease and other foreign matters must be removed from concrete surfaces by chipping, wire brushing, pressure washing, grinding, scabbling or by other means.
1.4 Any unevenness shall be tested with 300 mm straight edge. Maximum deviation shall be 1 mm per 300 mm. The edged of the structural member shall be rounded by grinding to achieve minimum radius of 10 mm.
1.5 All foreign materials shall be patched up with polymer modified cementitious mortar or other approved materials to receive the composite.
1.6 Any cracks greater than 0.3mm in width shall be injected by epoxy.
1.7 The contact surfaces of the member to be bonded with composite should be free of moist at the time of application. Humidity shall be less than 4%.
1.8 Where underwater application is necessary, a special epoxy that can be cured underwater shall be used.
2. Application of GRAND EPOPRIME CLEAR as primer
2.1 Concrete must be at least 3 to 6 weeks old depending on the climate.
2.2 Cleaning of the surface with a metal brush, sanding or water pressure.
2.3 The ‘hardener’ and ‘base’ components should be stirred separately before mixing to disperse any settlement.
2.4 Pour the entire contents of the hardener into the resin and mixed the two materials thoroughly using slow speed drill fitted with paddle for about 3-5 minutes until homogenous and uniform color is obtained. Allow the mix to rest for 10-15 minutes induction time to allow for chemical reaction.
2.5 Apply GRAND EPOPRIME CLEAR on the prepared substrate by means of brush or roller at the rate of 5-6sqm/liter. Mixed material must be applied within 30-40mins at 25°C.
2.6 Wait for the primer to be tack-free prior to application of EPOBOND PUTTY if needed to correct the surface profile at the rate of 1.70kg/sqm at 2mm thickness.
3. Application of MFORCE CF-20J/CF-30J
3.1 Saturate MFORCE CF-20J/CF-30J carbon fiber with GRANDFIX 300CFL laminating epoxy. Press this carbon fiber laminate firmly against the prepared substrate by hand by exerting a uniform tensile force that is distributed across the entire width of the fiber.
3.2 All the air bubbles or air pockets shall be squeeze out assuring a uniform and smooth final appearance. A rubber roll is being used to remove the air bells and to press the laminate in the perfect position.
3.3 The application shall be carried out when the epoxy resin matrix is in incurred state that the carbon fiber composite is highly flexible to conform and adhere to the contours of the substrate for effective bonding.
3.4 Gaps between composites band may not exceed 12.5mm.
3.5 A lap length of at least 150mm is required in longitudinal direction of the fibers for effective stress transfer. Vertical lap joints should be staggered.
4. Curing
4.1 Let the composite initially cured overnight prior to application of GRANDFIX 300CFL as final and protective coating.
5. Finishing
5.1 For plastering type finishes,the surface of the composite wrap may be roughened with coarse sand to ensure proper bonding.
5.2 The composite wraps may also be painted over with acrylic paint,a two-component uretahane coating. Any desired surface finish or protective fireproofing coating maybe applied on the cured composite surface.
6. Cleaning
6.1 Tools and equipment should be cleaned with GRAND EPOXY REDUCER immediately after use.
7. Safety Precaution
7.1 Wear rubber or plastic gloves to avoid contact with skin. Use soap and water to remove the mixture from hands. Do not use strong solvents to remove mixture from the skin.