tender for civil work - providing & placing of precast rcc benches at various locations in ward no. 221, ashok nagar sh ( n ) zone. ; 1 p / p of rcc benches 2 110.17:providing and placing of precast rcc benches ( chair bench with back rest ) using cement concrete grade m-30 consisting of 2 no. l-shaped base support of thickness 100 mm having back height 1000mm, front height 450mm and base width 620mm having 5 no. of rcc planks 1500x100x50 mm and one number plank of size 1500x200x50mm in the approved colour and shade; the minimum weight of ms reinforcement bar in the base support will be 3.4 kg having 4 nos. 8 mm dia m.s. bar distributed along the section and periphery of the legs with sufficient no of 4 mm dia ms stirrups. each base support will have 3 nos. 12mm dia ( 2 nos. 40mm and one number 65 mm long ) galvanised coupling nuts welded suitably to the main reinforcement at appropriate locations so as to receive bolts for fixing of seats of concrete planks on base support and 3 holes to received carriage bolts for fixing back rest planks. the minimum weight of ms reinforcement bar in the plank of 200 mm wide will be 4.4kg and of 100mm wide 2.9 kg. all the rcc planks will have 2 holes of 14mm dia at appropriate location, so as to receive 12mm dia galvanized bolts for foxing on the base support. one of the planks of size 1500x100x50 mm shall be engraved in the centre at the back with letter sdmc or as directed by engineer in charge, 2 planks of size 1500x100x50mm and 1 plank of size 1500x200x50mm will be bolted to coupling nuts provided inthe base support of both sides with 2 number of 12mm dia and 65mm long galvanized steel csk bolts and one eva washer for each bolt to form a seat; 3 planks of size 1500x100x50mm will be bolted to coupling nuts provided in both the base support to form back rest with 6 nos. ( two nos. in each plank ) half threaded carriage bolts and nuts of size 165m long and 8mm dia with eva and steel washers. the holes visible at the back side of the bench will be sealed with cement mortar after assembling. side edges of all the planks shall be painted with acrylic bases paint of approved colour and shade and front portion of seating and back rest planks shall be polished to give glossy finish complete as per direction of engineer-in-charge.