Reinforcement of the shear strength of a beam
RELATED MATERIALS:
- MEGAWRAP-200 carbon fabric for structural strengthening
- EPOMAX-LD two component epoxy impregnation adhesive
- EPOMAX-EK two component epoxy putty
- MEGACRET-40 high strength fibre reinforced repairing mortar
I. NATURE OF THE PROBLEM - REQUIREMENTS
- Increase of the beam's shear strength may be needed due to load increase or change of use, adjustment to new regulations, ageing of materials, corrosion of reinforcement, construction defects or earthquake repairs.
II. SOLUTION
- Shear strength can be increased by bonding MEGAWRAP-200 carbon fabric crosswise.
- The fabric forms continuous jackets or spaced ribbons around the beam; closed jackets offer the best behaviour but are often impractical, so U shaped jackets are usually used.
- MEGAWRAP-200 jackets are easy to install, increase strength without changing geometry or rigidity and protect the reinforcement against moisture and corrosion.
III. APPLICATION
- Prepare the concrete surface by removing loose parts, plaster, paint, oil and grease; clean thoroughly and rub with a hard brush.
- Repair existing cracks by resin injections.
- Flatten surface irregularities using MEGACRET-40 mortar or EPOMAX-EK epoxy paste.
- Coat the prepared surface with EPOMAX-LD resin.
- Cut MEGAWRAP-200 fabric to size, place it on the wet resin and press with a plastic roller to ensure contact and remove air bubbles; coat any dry spots with more EPOMAX-LD.
- For multiple layers repeat the process while the previous layer is still tacky; soak the final layer with EPOMAX-LD and broadcast quartz sand on the fresh resin so a protective cement based coating can be applied later.
IV. REMARKS
- Ensure excellent substrate preparation and effective anchorage of the jacket at its edges.
- Perform pull off tests to check substrate strength if necessary.
- Avoid folding or crumpling the fabric and keep it clean before application.
- Epoxy open time decreases at higher temperatures; during FRP applications the concrete surface temperature should be at least 5 C.
- Break the jacket every 600 mm to allow the element to breathe.
- Protect the applied jacket from high temperatures and coat it if exposed to sun.
- Use protective equipment such as gloves and goggles during application.
RELATED MATERIALS:
- MEGAWRAP-200 carbon fabric for structural strengthening
- EPOMAX-LD two component epoxy impregnation adhesive
- EPOMAX-EK two component epoxy putty
- MEGACRET-40 high strength fibre reinforced repairing mortar
I. NATURE OF THE PROBLEM - REQUIREMENTS
- Increase of the beam's shear strength may be needed due to load increase or change of use, adjustment to new regulations, ageing of materials, corrosion of reinforcement, construction defects or earthquake repairs.
II. SOLUTION
- Shear strength can be increased by bonding MEGAWRAP-200 carbon fabric crosswise.
- The fabric forms continuous jackets or spaced ribbons around the beam; closed jackets offer the best behaviour but are often impractical, so U shaped jackets are usually used.
- MEGAWRAP-200 jackets are easy to install, increase strength without changing geometry or rigidity and protect the reinforcement against moisture and corrosion.
III. APPLICATION
- Prepare the concrete surface by removing loose parts, plaster, paint, oil and grease; clean thoroughly and rub with a hard brush.
- Repair existing cracks by resin injections.
- Flatten surface irregularities using MEGACRET-40 mortar or EPOMAX-EK epoxy paste.
- Coat the prepared surface with EPOMAX-LD resin.
- Cut MEGAWRAP-200 fabric to size, place it on the wet resin and press with a plastic roller to ensure contact and remove air bubbles; coat any dry spots with more EPOMAX-LD.
- For multiple layers repeat the process while the previous layer is still tacky; soak the final layer with EPOMAX-LD and broadcast quartz sand on the fresh resin so a protective cement based coating can be applied later.
IV. REMARKS
- Ensure excellent substrate preparation and effective anchorage of the jacket at its edges.
- Perform pull off tests to check substrate strength if necessary.
- Avoid folding or crumpling the fabric and keep it clean before application.
- Epoxy open time decreases at higher temperatures; during FRP applications the concrete surface temperature should be at least 5 C.
- Break the jacket every 600 mm to allow the element to breathe.
- Protect the applied jacket from high temperatures and coat it if exposed to sun.
- Use protective equipment such as gloves and goggles during application.
