Gail Mangalore Petrochemicals Limited Tender

Expansion Joints repair The treatment includes several steps to address expansion joint repair in concrete surfaces as outlined below: (i) Ensure that the joint surfaces are dry. Chipping is done using power/hand driven chisel to remove any loose material, previously filled material or sealant from the edges The RCC surface is to be cleaned using wire brush to ensure a sound substrate for joint treatment. (ii) Chipped edges or lost section are to be repaired using polymer modified mortar (1:3 of Cement: Graded Clean River Sand) with SBR Latex in layers not exceeding 6-10 mm thick, conforming to the manufacturer's specifications including trowelling with wooden tools, should be applied on-site after an SBR-based bonding coat in the ratio (1:1.5) as per manufacturer's specifications. It is applied on the existing/cleaned surface to ensure proper adhesion between the substrate and the new materials as per the manufacturer's instructions. (iii) Providing, laying and fixing of expansion joint with compressed seal gasket, laying Backing rod as per site requirement, thick duly pasted with epoxy adhesive underneath (if required), and applying two part, tough and elastomeric Polysulphide Sealant, conforming to BS:4254 as per manufacturer’s specifications to allow the sealant to set fully. (iv) An EPDM layer of (150mm X 1.2 mm) or as per site requirement thick duly pasted with epoxy adhesive underneath is to be applied over the joint and duly anchored with stainless steel screw on aluminium plates.

Construction joints repair The treatment includes several steps to address construction joint repair in concrete surfaces as outlined below: (i) The affected portion of the joint may be opened and cleaned to remove any loose material, dust particles, or previously filled material using water and air jet, mechanical grinding with pneumatic machines, or wire brushing to expose a sound substrate. A U-shaped Groove shall be made along the crack length and the crack shall be cleaned with air and water jet and the surface is ensured to be dry. (ii) Fixing injection ports or nozzles in RCC members, including drilling holes into the concrete of 12 mm dia or as per site requirement to an appropriate depth at required spacing by the approved manufacturer or as per the directions of the Engineer-in-Charge but not exceeding the thickness of member. Holes should be cleaned using an air blower prior to fixing the nozzles to ensure proper adhesion of material to the surface and shall be sealed with a moisture-insensitive epoxy resin-based putty or polymer modified mortar or equivalent material as per the directions of the EIC (iii) Epoxy grout or polyurethane resin which is a two-part epoxy system consisting of (resin and hardener) should be mixed as per manufacturer's specifications. The mixture is then injected into the crack through the ports under controlled pressure as per the directions of the EIC (iv) After completing the grouting injection ports or nozzles are cut flush with the surface using a cutting tool. (v) An anti carbonation coating in 2 coats is to be applied over the treated plaster surface, the minimum coating thickness is to be 200 microns or as per manufacturer's specifications and directions of EIC.

Honeycombing Treatment: The treatment includes several steps to address seepages, leaks, and honeycombing/surface porosity in concrete surfaces, with affected areas as outlined below: (i) The affected area is to be cleaned through chipping, which is done using power or hand-driven chisels to remove loose material, laitance, and contaminants, exposing a sound substrate. (ii) The exposed reinforcement on the surface is to be thoroughly abraded to remove loose rust, stubborn stains, and scales using coarse wire brushes or cup wire brushes attached to hand tools, before applying anti-rust agents. Providing and applying two coats of Anti-corrosive protective coating to exposed and cleaned reinforcement bars using zinc-rich primers on old exposed and thoroughly cleaned reinforcement. (iii) The surface is to be made dry before application of SBR based coating in the ratio (1:1.5) or as per the manufacturer's specifications. The honeycombed area is then to be filled using polymer modified mortar in ratio of (1:3 of Cement: Graded Clean River Sand) in layers not exceeding 6-10 mm thick, conforming to the manufacturer's specifications including trowelling with wooden tools to ensure proper bonding and finish that matches the surrounding. (iv) Fixing injection ports or nozzles in RCC members, including drilling holes into the concrete of 12 mm dia or as per site requirement to an appropriate depth but not exceeding the thickness of member. Holes should be cleaned using an air blower prior to fixing the nozzles and shall be sealed with a moisture-insensitive epoxy resin-based putty or polymer modified mortar or equivalent material as per the directions of the EIC. Epoxy grout or polyurethane resin which is a two-part epoxy system consisting of (resin and hardener) should be mixed as per manufacturer's specifications. The mixture is then injected into the crack through the ports under controlled pressure as per the directions of the EIC (v) An anti carbonation coating in 2 coats is to be applied over the treated plaster surface, the minimum coating thickness is to be 200 microns or as per manufacturer's specifications and directions of EIC.