The following safety measures are taken during civil engineering construction. (i) Suitable scaffolds should be provided for workmen. (ii) When ladder are used, it should be provided with foot holds and hand holds and inclination of one is to four (1 horizontal : 4 vertical) be provided. (iii) The scaffolding should be properly supported and shall have a guard rail property attached to it. (iv) Every opening in floor of a building should be provided with suitable means to prevent the fall of persons or materials. (v) Fencing and lights shall be provided to protect the public from accident. (vi) The excavated material shall not be placed within 1.5m of the edge of the trench or half the depth whichever is more to avoid collapse of sides due to surcharge. (vii) No undermining or undercutting shall be allowed. (viii) All roads and open areas adjacent to any side where demolition is to be carried out, must be closed or suitably protected. (ix) No electrical cable etc. shall remain electric...
Construction of Cantilever RCC Slab:
The following steps would be involved:
(i) Form Work: Staging should be designed and erected. The staging shall be of tubular steel structure with adequate bracing as approved or made of built up structural section made from rolled structural steel sections.
Shuttering used shall be of sufficient stiffness to avoid excessive deflection and joints should be tightly butted to avoid leakage of slurry. If required rubberised lining of material shall be provided in the joints. Steel used for concreting should be suitably stiffened. It should be properly repaired before use and it should be ensured that it is properly cleaned to avoid stains, honey combing, seepage of slurry etc. The holes, if any must be plugged.
Suitable camber shall be provided to counteract the effect of deflection. The camber at free ends shall be 1/50th of the projected length.
The shuttering must be coated with mould oil.
(ii) Placing of Reinforcement: The reinforcement shall be provided as per the structural design/ drawing duly approved. Bars must be bent correctly and accurately to the specified size and shape. Overlapping of bars, where necessary shall be bound together at intervals not exceeding twice in dia. of such bars with two strands annealed wire of 0.9mm to 1.6mm dia. twisted tight. The bars crossing one another shall also be twisted tight to make the skeleton of steel work rigid to avoid displacement during concreting. Chairs, spacers or support bars shall be introduced at 1m or shorter intervals.
(iii) Concreting: Concrete cement, coarse aggregate and fine aggregate shall be mixed with water in required proportions in a mechanical mixer to obtain concrete of required workability. Cat walks of chequered MS plates or bamboo chalies supported directly on the centering by means of wooden blocks or lugs shall be provided to convey the concrete to place of deposition without disturbing the reinforcement. The concrete shall be deposited in its final position in a manner to preclude segregation of ingredients. No concreting shall be allowed when the temperature falls below 4.5 degree C or when the temperature of wet concrete is above 38 degree C. The deposited concrete shall be compacted with the help of vibrators or otherwise. Top surface of the concrete shall be finished even and smooth with wooden trowel before it begins to set.
The concrete shall be cured after 24 hours of its laying minimum for 7 days from the date of placing concrete.
Comments
Post a Comment
Kindly let me know, if you want to know anything.