Providing water proofing for expansion joints at several leakage/seepage points on roof of Central Hospital under Ib Valley Area

Amount

Removing of old tarfeit/bitumen sheet from roof top, over parapet wall making the surface free from any residual by applying heat if needed and fit for relaying of water proofing bitumen felt including disposal of rubbish to a specified space shown by EIC.

Demolishing cement concrete manually/ by mechanical means including disposal of material within 50 metres lead as per direction of Engineer - in - charge. Nominal concrete 1:3:6 or richer mix (i/c equivalent design mix)

Grading roof for water proofing treatment with Cement mortar 1:3 (1 cement : 3 coarse sand)

First part consist ol'all expansion joint surface should be cleaned up b1 hacking tool, wire brush, grinder & air blo$er etc and all unsound particle may be removed. This shall be followed by preparing the joints by supplying and applying rcady-to-usc single componcnt rapid hardening, First part consist of all expansion joint surface should be cleaned up by hacking tool, wire brush, grinder & air blower etc and all unsound particles may be removed. This shall be followed by preparing the joints by supplying and applying ready-to-use single componcnt rapid hardening,high strength, nonshrink repair mortar which requires only the addition of clean potable water to produce highly consistent repair monar, of Masterrepair Qwikfix of Choksey Chemicals, Grace. or Sika/Saint Gobain. The product shall be based on a blend of portland cement, graded aggregates, fillers. polymers & additives. The mortar when mixed with water hardens rapidly within I hour & can be trafiicked after 2 hours. The low water powder ratio of the product ensures better high early strength development and thus provides long-term durability, high strength ready to use material shall be such which shall be suitable the use as a structural patch repair material for concrete oadways, potholes filling, parking areas, warehouses, where quick repairing is required together with long term durability.and suitable for (a) repairing of damaged concrete structures and economical patching material for horizontal repairs of concrete., b) For localizcd patch repairs and can be used for repair of old wom-out concrcte floors. The product shall be such which is designed for application in sections irom 6 to 50 mm thickness layer and fbr largcr sections the addition of approved aggregates may bc required depending on the specific conllguration ofthe repair location.( mix 8mm - l2 mm coarse saturated surf'ace dry'. lou absorption, graded ggregate in the product (Aggregatc conrent : 30 to 50% by weight of the roducr). High Strenglh reaJ) to sue morlar shall harc thc follorring inimum pronenies : a) Compressive strength in N/sqmm shall be minimum l6 atier 24 hours: minimum l0 after 24 hrs; minimum 35 after 3 days and minimum 40 after 28 days: (b) tensile strength shall be minimum 3 N/sqmm after 28 da)s . (c) flexural strength shall be minimum 6 N sqmm after 28 days. Chloride content

Second part shall be applying backer rod prior to fllling and sealing the expansion joint with TECHSEAL RDL 940 Super,2 component polysulphide sealant, manufactured by Choksey Chemicals or an equivalent product of Grace/ Elantas Beck/Huntsman based on'THIOKOL' - Polysulphide liquid elastomer. 2 component polysulphide consists of a'base' compound and 'accelerator' (Curing Agent). When the two components are mixed together prior to application, a chemical reaclion is initiated which cures instantly to a firm, flexible rubber like seal which has excellent adhesion to concrete, masonry, wood, glass, acryiic and PVC plastics. lt is capable of withstanding repeated extension, compression & cyclic movements without the loss of adhesion and resists deterioration by weathering, sunlight, ozone, water, salt, oils and fuels. lt is far superior to all the conventional joint sealing material like bitumen, mastics, metallic channels and expansion sheets. lt is a non-sag material used lor sealing of horizontal, vertical & ceiling joints . As the joint expand, contract or experience a shear movement, cyclic movements, sealant changes the shape accordingly, but the volume of sealant remains same. Hence, in filling the joints, it is vital that the proper width-to-depth ratio is speclfied so that the width of the joint is consislent with the capability of the sealant to endure daily and seasonal cydes for prolonged periods. The amount of movement in a joint is dependent on the length (span), the coefficient of linear expansion of a panel section and the temperature differential of the substrate. To achieve the longterm, effective performance the established width-todepth ratios are determined and for joints width from from 12.5mm to 25mm, depth of selanat shall be minimum 12.5mm. It shall be applied alter application ol Techseal RDL 42 primer

Third step shall be supplying and installing FLEXPRUFE FPO (flexible polyolefin) of Choksey Chemicals/ Combiflex of Choksey Chemicals, joint sealing tape provides waterproofing with suitable Masterbond EP of Choksey Chemicals epoxy resin or equivalent of Sika for waterproofing of expansion joints in areas with high or frequent movements. FPO expansion joint tape shall be highly flexible with high crack and joint bridging ability, have good chemical resistance , have good resistance to ageing ; have resistant to UV exposure ; have resistant to root penetration ; and performs well within a wide range of temperatures ; Plasticiser-free i Hot air weldable . FPO of Choksey Chemicals /Combiflex of Sika shall have following minimum properties: (a) Thickness : 1mm; (b) Width : 200mm ; (c) Tensile skength (length/cross) shall be minimum 12.5 N/sqmm (as per DIN 12311); (d) Elongation :>500% (as per DIN 12311); (e) shore a hardness >87

Total impact of GST plus Labour Cess [@ 1 % (BOCW Cess to be deducted from the RA bill as per the value of the work progress)] for the purpose of CTC

M/S SMRUTI RANJAN NAYAK

SEEMA NAGAYACHA