Balaram Bridge

Work Methology Adopted

Application of polymer modified cement grout

  • Wearing coat was removed.
  • Naked top surface was cleaned with compressor air and water jet.
  • 20 mm dia holes, depth 200 mm, distance of 500 mm c/c were drilled by electrical machine and PVC nipple was fixed with polymer modified cement mortar.
  • Cement=50 kg, Cebex=225 gr, water=20 lt, Tapcrete p-151=7.5 Kg. were mechanically mixed and grouting done by grout pump with compressed air pressure of 3 kg/cm2 to 5kg/cm2 and grouting was carried out till there was rejection from nipple. After grouting nipples above slabs were cut and surface was leveled with PMC mortar.

Application of polymer modified cement mortar

  • Chipping the concrete surface up to full circumference of steel.
  • Cleaning the reinforcement by wire brush then rust removal compound i.e. Reebaklens RR of Forsroc was applied then again cleaned by wire brush.
  • One coat of zinc rich coating of Nitozinc Primer of Fosroc was applied.
  • Bond coat- Tapcreate P-151 mixed with two part of cement by weight of thick paint & applied for bonding on new PMC.
  • Cement=10 kg, sand=30 kg, Tapcreate P-151, water= 3 lt. mechanically mixed and applied in 2 layers up to 50 mm thickness

Application of epoxy mortar

  • Cracks were demarcated in R.C.C. & mechanically cut in V shape groove of 20*20 mm size.
  • Groove was filled with epoxy mortar 2:1:20 (Resin: hardener: Silica sand – by weight).

Application of epoxy grouting

  • Fixed 10 mm dia. metal nipple, depth 200mm, interval 300 mm in hole in cracks and sealed hole with epoxy mortar.
  • Lapox B47 & K 46 of Atul Limited in ratio of 2 resin 1 hardner by volume is mixed and grouted with small gun attached with small air compressor at 3 Kg/ cm2 pressure from bottom to top.
  • After grouting nipple above the concrete is cut and surface is leveler by PMC mortar.

Application of wrapping

  • Primer- Epoxy primer Nito Wrap 30 was applied over the prepared and cleaned surface by brush and allowed to dry for 24 hours before application of saturant.
  • Saturant- The mixed material of nitowrap 410 saturant was applied over the tack free primer. The wet film thickness was maintained @250 microns.
  • Nitowrap glass fibre- The Nitowrap glass fibre was cut to required size and than pressed first by gloved hand on the saturant applied area then with a stiff spatula and Surface roller to remove air bubbles. One more coat of Nitowrap 410 saturant was applied over the glass fibre @ 250 microns.

Application of micro concrete

  • Provided fixed water tight shuttering for pedestal.
  • Mix is prepared by adding of 1part by weight of Renderoc RG Micro concrete powder of Fosroc and 1 part by weight of grit (4.75mm to10mm) and required quantity water for workability. The mixes were mixed thoroughly by mechanical stirred for about 3 mins.
  • Then flowable mix were poured and there was no need for compaction as it is flowable and self compacting mix.