Repairs and Maintenance works at Tarapur Lighthouse Station.

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

Dismantling steel work in built up sections (main gate and tower plinth hand rail) in angles, tees, flats,pipe and channels including all gusset plates, bolts, nuts, cutting rivets, welding etc. including dismembering and stacking within 50 metres lead complete as directed by the engineer in charge

Providing and laying 75 mm thick compacted bed of dry brick aggregate of 40 mm thick nominal size including spreading, well ramming, consolidating and grouting with jamuna sand, including finishing smooth etc. complete as per direction of Engineer-in-charge.

50 mm average thickness

Removing loose rust from the reinforcement bars by wire brushing, light hammering etc. and applying sulphate and chloride free inorganic single component rust remover Rusticide as approved by Engineer in charge conforming to IS 9077. The rusted surface shall become blackish non rusted colour. After 24 hours of application of rust remover, loose particles shall be removed by brush. Apply one more coat of Rusticide. Apply bonding coat slurry of high performance acrylic polymer - Methyl 2-methylpropenoate copolymer with another enoate as approved by Engineer in charge on entire surface. Mix 1 Kg of acrylic polymer with 0.5 Kg of cement. Finish it with ready to use repair polymer modified mortar based on special cements, aldehyde based polymers with thixotropy modifying agents as approved by Engineer in charge (The Polymer Modified Mortar (PMM) should attain min. compressive strength of 20 N/mm2 in 1 day and 30 N/mm2 in 7 days) by adding 13 - 16% water by weight of polymer modified mortar for treatment to the damaged RCC members. Add 1 Kg of Migrating Corrosion Inhibiting Admixture as approved by Engineer in charge per 25 Kg bag of polymer modified mortar. After mixing polymer modified mortar, it can be trowel applied or sprayed. When applying by hand, polymer modified mortar must be forced tightly into the substrate to ensure complete contact with the substrate cost inclusive of scaffolding , tools etc. all complete.

6 mm plaster on cement concrete of reinforcement cement work with cement based polymer modified self curing mortar of approved make as per the direction of Engineer-In-Charge.

Providing and applying fibre reinforced elastomeric liquid water proofing membrane (Roff/Weber saint gobin/Basf/ Fosroc) with resilient acrylic polymers having Sun Reflectivity Index (SRI) of 105 on top of concrete roof in three coats @10.76 litre/ 10 sqm. One coat of self-priming of elastomeric waterproofing liquid (dilution with water in the ratio of 3:1) and two coats of undiluted elastomeric waterproofing liquid (dry film thickness of complete application/system not less than 500 microns). The operation shall be carried out after scrapping and properly cleaning the surface to remove loose particles with wire brushes, complete in all respect as per the direction of Engineer-in-Charge.

Grading roof for water proofing treatment with Cement concrete 1:2:4 (1 cement : 2 coarse sand : 4 graded stone aggregate 20mm nominal size) finished after hacking of the top slab surface including providing and mixing water proofing material in cement plaster work in proportion recommended by the manufacturers of approved make (Roff / Fosroc/ Basf/Weber saint gobin), etc. complete as directed by the engineer in charge.(upto height of 10 m from ground level) as per direction of Engineer-in-Charge

Repair to plaster of thickness 12mm to 20 mm in patches of area 2.5 sqm and under, including cutting the patch in proper shape, raking out joints and preparing plastering the wall surface with white cement based polymer modified self curing mortar, including disposal of rubbish, all complete as per the direction of Engineer-In-Charge.