WBPWDRoadsEEBNHDNIT04/26-27-1

Dismantling of existing structures like culverts, bridges, retaining walls and other structure comprising of masonry, cement concrete, steel work, including T&P and scaffolding wherever necessary, sorting the dismantled material, disposal of unserviceable material and stacking the serviceable material with all lifts and lead of 1000 m as per Technical Specifications Clause 202 for Rural Roads of MORD. (I) By Manual Means, c) Reinforced cement concrete

Picking up and removing old bituminous layer or sand sealing coat from old black topped surface and cleaning the exposed surface by scraping and stacking the material as directed. (a) By manual means : (i) From 25 mm to 50 mm thick.

Guniting concrete surface with cement mortar (25 mm nominal thick) applied with compressor after cleaning surface and spraying with epoxy complete as per Technical specification.

Removal of defective concrete, cleaning the surface thoroughly, applying the shotcrete mixture mechanically with compressed air under pressure, comprising of cement, sand, coarse aggregates, water and quick setting compound in the proportion as per clause 2807.1., sand and coarse aggregates conforming to IS: 383 and table 1 of IS: 9012 respectively, water cement ratio ranging from 0.35 to 0.50, density of gunite not less than 2000 kg/cum, strength not less than 25 MPa and workmanship conforming to clause 2807.6. (40 mm average thickness.)

Epoxy bonding of new concrete to old concrete

Cleaning the concrete surface by removing dirt and debris, marking defective locations and removing loose concrete by careful stripping untill hard surface is exposed, cutting the concrete to regular shape, wire brushing the exposed surface and removing debris from site complete as per direction of the Engineer - in - Charge.

Applying epoxy mortar ( 10 mm nominal thick) over leached, honey combed and spalled concrete surface and exposed steel reinforcement complete as per Technical specification.

Providing and inserting nipples with approved fixing compound after drilling holes for grouting as per Technical specifications including subsequent cutting/removal and sealing of the hole as necessary of nipples after completion of grouting with Cement/Epoxy.

Sealing of crack / porous concrete with Epoxy Grout by injection through nipples complete as per clause 2803.1.

Cleaning the exposed corroded Reinforcement as well as worn out concrete by sand blasting with air compressor including all materials, hire charges of machineries and labour etc. all complete as per technical specification and direction of the Engineer-in-Charge.