DRIP Phase II

Amount

Treatment of Crack Size 25 mm x 25 mm (Where leakage is not observed from the crack)

Treatment of Cracks - Remove all foreign materials, loose concrete, plastering etc. with chisel and hammer from the crack surface so as to reach the sound surface of the concrete. Clean the surface with compressed air and water jet. Cut groove of size 25 mm (wide) and 25 mm (deep). Drill about 50mm deep hole at 2 meter intervals along the crack for fixing 12.5mm nozzles for grouting. Remove all loose material by blowing compressed air and saturate the slot with water and allow the water to soak into the concrete and remove surface water. Groove shall be primed with XYPEX Megamix II or equivalent product with similar specification and certification which will act as bonding coat. Application shall be performed with brush. While this slurry coat is tacky, fill slot to surface with XYPEX Megamix II or equivalent mortar of 1 part clean water to 7 parts of Megamix II or equivalent and blend by trowel.

Supplying and fixing nozzles of 12.5 mm dia and 150 mm length along the length of chipped crack into the concrete mass. Nozzles shall be fixed at a distance at 2 meter intervals. Depending upon the grout intake, intermediate nozzles can be considered as per the direction of departmental officers.

Providing and applying grout mixture consisting of XYPEX C2000 NF or substance with equivalent specification and Micro fine cement of grain size D95 < 20 microns (Alccofine 1108SR or equivalent) in a ratio of 1 : 5 through the fixed nozzles to the cracked structure. Grouting shall be done in very tight joint and the grout should have high rate of penetration. The crack shall be grouted through each nozzle. The grouting equipment should have a colloidal mixer, an agitator, a pump, suitable high pressure hoses, valves and pressure gauges. A high-speed colloidal mixer (1500 to 2000 rpm) shall be used to prepare each batch of grouting mix. The grouting mix shall consist of microfine cement grout with an admixture having crystalline properties (XYPEX Admix C2000 NF or equivalent) The injecting shall start with a mix 3 vol. water to 1 vol. of micro-cement grout , then continue with 2 to 1 and finally all process finished off with a mix 1 to 1. The maximum injecting pressure shall be 2 to 3 Bar. Once completed and grout is completely set, the projected part of the nozzles shall be removed, surface shall be cleaned and finished smooth.

Durability Enhancement Treatment of Dam Gallery Concrete Structure: Applying a slurry coat of XYPEX Concentrate or equivalent at coverage rate of 0.80kg/m2 over the repaired crack in 30 cm width to make the whole surface water tight. Cure by water spraying periodically for two days after the slurry coat has set.

Providing and fixing double scaffolding system if necessary (cup lock type) made with 40 mm dia. M.S. tube at 1.5 m C/c, horizontal & vertical tubes joining with cup & lock system and maintaining it in a serviceable condition for the required duration as approved and removing it thereafter. The scaffolding system shall be stiffened with bracings, runners, connection with the building etc. wherever required for inspection of work with essential safety features for the workmen etc. complete as per directions and approval of Engineer- in Charge. The elevation area of the scaffolding shall be measured for payment purpose. The payment will be made once irrespective of duration of scaffolding.

APAAR INFRATECH PVT LTD

Bidder Name

APAAR INFRATECH PVT LTD

BHARATHI ENGINEERING CORPORATION