Strengthening

Beams strengthening

  • Plaster from the beam surface to remove carefully by chipping with the Chipper machine.
  • Fix laminates on top of the beam, remove flooring from that portion to expose the beam concrete surface.
  • Make a light tapping on beam concrete surface to check damage and honeycomb concrete area etc.
  • Identifying and mark damage area. Then remove carefully by chipping with breaker machine.
  • Clean concrete surface off any loose particles, dust, oil residues etc.
  • Repair Damage area using polymer modified mortar. Any undulations, pin holes present on the surface to fill up with the site made polymer & cement putty.
  • All the corners/edges rounded off smooth to 25 mm radius with the help of grinder.
  • Remove all debris from the workplace and collect at one place identify for further removal.

Application of Laminate Adhesive and Laminates:

  • Laminate adhesive, Master Brace 4000, components A & B to mix in the prescribed proportion mechanically as per the manufacturer’s specification until a homogenous uniform colored mix is obtained.
  • One layer of laminate adhesive, around 3-5 mm thick to apply on the prepared concrete surface as well as on the one side of the laminate. cut laminate to the required length and kept ready.
  • Master Brace Laminate having 100 mm width to fixed on the concrete surface and using the hard roller, constant pressure to exerted by moving the roller in the direction of laminate or along the length of the laminate. Hold the Laminate in that position for a while till it sticks to adhesive properly. To do this use jack prop in the center and at the end.
  • The prescribed number of laminates to apply on the beam bottom surface, beam sides and on the beam top surface at the ends for the length as specified with spacing.
  • Remove the props after laminates have properly adhered to the surface. The same will take a couple of hours depending on the ambient temperature.
  • The laminates adhered on the top of the beam to fix using an aluminum plate and Hilti anchors.

 

beams strengthening

 

Carbon fiber wrapping for strengthening in flexure:

Surface Preparation:

  • After carbon laminates properly adhere to the surface, the gap between two carbon laminates is fill up with site mix polymer cement putty to level the surface. For this, the acrylic polymer of BASF and Cement are mix together to form the putty-like consistency. Using painters’ blade apply putty over the concrete surface to make the concrete surface level with laminates.
  • Allow the putty to cure for a day before taking up fiber wrapping work.

Primer Application:

  • Mix Master Brace 3500 Primer, Part A & B together in prescribed proportion as per technical data sheet using mechanical stirrer.
  • mix material to the clean surface.
  • application to carry out using a nylon brush and allow for drying for about 6 to 10 hours before application of saturant.

Saturant and Fibre Application:

  • Carbon Fibre reinforcement system to cut to required size before application of the saturant.
  • Mix epoxy saturant, Master Brace 4500 part A & B thoroughly by a mechanical stirrer to get a uniform colored mix.
  • First coat of the fully mixed saturant resin to apply to the concrete surface i.e. beam bottom & sides as well as 300 mm on slab soffit on either side of the beam, by Nylon brush.
  • Immediately fix pre-cut Master Brace Carbon Fibre over the surface. The orientation of the fibers must be in the correct direction. In case of beams, the orientation of fibers must be in a vertical direction. That is, perpendicular to main horizontal reinforcement steel.
  • The fiber reinforcement system is strongly squeezing in the longitudinal direction of the fibers two or three times using a deforming roller and rubber spatula in order to impregnate the resin into the fibers and to deform the resin coat.
  • Ends of the fiber sheet are extent on the slab bottom surface by 300 mm. Two fiber sheets to be overlap and additional resin to apply at the overlap location on top of the outer layer of fiber sheet to be overlap.
  • The adhered fiber reinforcement system is allowed to stand for at least 30 minutes.Any lifting or dislocation that occurs during this period will be corrected using the roller.
  • The second or overcoat of mixed saturant to apply onto the surface of the fiber sheet after the first coat is sufficiently dry. The coated surface is strongly squeezed in the fibers in longitudinal direction two or three times with the roller and spatula in order to impregnate the fiber sheet as above.
  • While still, the second coat is tacky, quartz sand to sprinkle over the surface to make it rough.

Carbon fiber wrapping for strengthening in Shear:

Surface Preparation:

  • prepare Plaster from the slab soffit as well as from beam surface for the length at the ends.
  • A light tapping on the beam concrete surface to carry out to check the damage and honeycomb concrete area etc.
  • identify and mark damage area to remove carefully with breaker/chipper machine.
  • Entire concrete surface to clean off any loose particles, dust, oil residues etc.
  • Damage and chip off an area to repair using polymer modified mortar. Any undulations, pin holes present on the surface to fill up with a site made polymer & cement putty.
  • All the corners/edges are round off smooth to 25 mm radius with the help of grinder.
  • remove All debris from the workplace and collect at one place identify for further removal.

Primer Application:

  • Mix Master Brace 3500 Primer, Part A & B together in prescribed proportion as per technical data sheet using mechanical stirrer.
  • mix material to apply to the prepare and clean surface of beam and slab soffit.
  • The application to carry out using a nylon brush and allow for drying for about 6 to 10 hours before application of saturant.

Saturant and fiber Application:

  • Mix epoxy saturant, Master Brace 4500 part A & B thoroughly by a mechanical stirrer to get the uniform colored mix.
  • First coat of the fully mixes saturant resin to apply @ 500 gms per coat per sqm area on the concrete surface by Nylon brush.
  • Immediately fix pre-cut Master Brace Carbon Fibre over the surface. The orientation of the fibers must be in the correct direction. In case of beams, the orientation of fibers must be in a vertical direction. That is, perpendicular to main horizontal reinforcement steel.
  • The fiber reinforcement system to strongly squeeze in the longitudinal direction of the fibers two or three times using a deforming roller and rubber spatula in order to impregnate the resin into the fibers and to deform the resin coat.
  • Ends of the fiber sheet to extend by 300 mm on the slab soffit on either side of the beam.
  • Two fiber sheets to overlap and additional resin to apply at the overlap location on top of the outer layer of fiber sheet to be overlap.
  • The adhered fiber reinforcement system to allow to stand for at least 30 minutes. Any lifting or dislocation that occurs during this period to correct using the roller and spatula.
  • The second or overcoat of mixed saturant to apply onto the surface of the fiber sheet after the first coat is sufficiently dry.
  • The coated surface to strongly squeeze in the fibers in longitudinal direction two or three times with the roller and spatula in order to impregnate the fiber sheet as above.
  • While still, the second coat is tacky, quartz sand to sprinkle over the surface to make it rough so that plaster applies later on.

 

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One thought on “Strengthening of Beams in Flexure/Shear by using MasterBrace Laminate & FIB system”
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