Building Repair & Renovation Tenders

Providing and fixing double scaffolding system (cup lock type) on the exterior side, up to seven story height made with 40 mm dia M.S. tube 1.5 m centre to centre, horizontal & vertical tubes joining with cup & lock system with M.S. tubes, M.S. tube challies, M.S. clamps and M.S. staircase system in the scaffolding for working platform etc. and maintaining it in a serviceable condition for the required duration as approved and removing it there after. The scaffolding system shall be stiffened with bracings, runners, connection with the building etc wherever required for inspection of work at required locations with essential safety features for the workmen etc. complete as per directions and approval of Engineer-in-charge. ( Note : The elevational area of the scaffolding shall be measured for payment purpose. The payment will be made once irrespective of its nos. of times of usage, duration etc. of scaffolding. Only additional payment towards supply of unskilled labours during each occasion of shifting and reerection of scaffolfing will be given . No extra payment will be admissible towards hire charges of scaffolding throughout the duration of project. Payemt will only be given for the specified qty of 300 sq. meters / the quantity of scaffolding actually delivered at site for this purpose . -This item and the system shall be judiciously used for providing temporary support to the longitudinal cantilever chajjas of the building, solely for facilitating external structural repairs at the descretion of Engineer In charge .)

PMM REPAIR WORK UP TO 20 MM ON WALL (UPTO CHAJJA) & MUMTY ROOM :Repairing to the existing RCC structural members (vertical or horizontal) using ready mix Polymer Modified Mortar (Fibre reinforced structural grade repair mortar) of approved brand where the thickness of repair is up to 20 mm. Surface preparation- All loose traces of concrete or mortar, dust, grease oil, etc. must be removed. Damaged or contaminated concrete shall be removed to obtain a keyed aggregate exposed surface. Clean the surface using high pressure water blasting. Clean all exposed reinforcement to a minimum grade of Sa 2 according to ISO 8501-1 / ISO 2944-4. Ensure all visible portions of the reinforcing bar is clean. Where reinforcing bars are corroded, cut back the concrete around the reinforcing bars, Grit blast to remove corrosion products from around reinforcing bars and coat with approved epoxy coating for corrosion protection as recommended by the Engineer. Replace the affected part of rebar if the diameter after grit blasting is found reduced by more than 20% of the original diameter on the advice of the engineer. Bond Coat- Providing & applying One coat of structural grade epoxy bond coat by brush conforming to ASTM-C-882-87 to the prepared concrete surface to be repaired / strengthened and repairing with PMM shall be done when the surface is tacky. Mixing - Only full bags are mixed. Damaged or opened bags should not be used. Mix the ready-mix Polymer Modified Mortar in a forced action pan mixer, or with a helical paddle attached to a low speed (300-600rpm) mixer for 3 minutes until a lump free, thixotropic consistency is achieved. Only use clean water. Mixing water needed: 3.75 to 4.25 litres per 25kg bag or as recommended by the Manufacturer of Polymer Modified Mortar. Allow the mortar to rest for 2 - 3 minutes and then remix briefly before pouring into formwork. If temperature more than 40°C then use chilled water for mixing. Mortar application - The minimum temperatures must be maintained during application and for at least 24 hours thereafter for optimum curing of the product. The prepared substrate should be presoaked, preferably for 24 hours, but at least 2 hours before applying Polymer Modified Mortar. The surface must be saturated surface dry, but without standing water. Polymer Modified Mortar can be spray- or hand-applied. Apply mixed product directly to the prepared damp substrate, or wet on wet onto the primed surface. Spraying the material with the necessary pressure will ensure good adhesion of the material. A thin scrape coat or contact layer before building up to the required thickness, wet on wet, will improve adhesion especially in case of hand application. Apply to the desired layer thickness upto 15 mm and level using a screeding bar, trowel or wooden board. Smoothing with a trowel or finishing by float or sponge can be done as soon as the mortar has begun to stiffen. Protective coatings- Subsequent coatings of any ant carbonation barriers or silane impregnations should be applied if recommended by the Engineer. Plaster- The repaired surface shall be matched to the surrounding surface by providing required thickness of plaster internal or external plaster. Curing - Minimum 7 days curing shall be done to the newly repaired area using any suitable method.