SPECIAL REPAIRS AND REPLACEMENT OF CONCRETE SLABS OF PQC MATERIAL ON DUMBBEL DB OF MAIN RUNWAY 10/28 AT INS DEGA, VISAKHAPATNAM

Demolition of un-reinforced cement concrete in ground floors and pavings exceeding 15 cm thickness (below or above ground level) complete all as specified and as directed

Demolition of un-reinforced cement concrete in ground floors and pavings not exceeding 15 cm thickness (below or above ground level) complete all as specified and as directed.

M&L for Laying Dry lean concrete (DLC) 150 m thick of aggregate gradation as per Table 1 of SP 49:2014 having 7 day avearge compressive strength not less than 140 Kg/Cum DLC mixed in Batching plant, transported to site and laid by elctronic sensor paver including spreading and compacting using high amplitude temping Bars of paver (initial compaction) further by double drum smoth wheeled vibrator rollers with 80-100 KN static weight to achieve minimum dry density, necessary finishing etc., and tolerances to be as per Table 900-1 of MoRTH specifications for Road and Bridge work 2013 complete all as specified and as directed.

M&L for 10 mm thick sand cushion with clean river sand duly clear of residual , organic and deleterious materials spread evenly to uniform thickness laid over DLC layer complete all as specified and directed

Suply & Lay 400 micron thick HDPE sheet (Virgin Quality) water proof, wrinkle free without puncture having minimum weight 390 gm/sqm over tack coat / sand cushion as specified in the design with overlap between strips and at transverse joints as minimum 300mm complete all as specified and as directed.

M&L for Pavement Quality concrete (PQC) of minimum 28 days field flexural strength of 45 Kg/Sqcm or 4.5 Mpa, aggregate gradation as per Table 3 of IRC 15-2017, coarse aggregate of clean, hard strong, dense, non-porous and durable pieces of crushed stone or gravel, fine aggregates of clean natural sand or crushed stone sand or combination of both using minimum 360 Kg/Cum of cement with non-circular, virgin synthetic fibre of 12-18 mm length, specific gravity 1.34 to 1.39, UV stable, alkali resistant, with equvalent, with equivalent dia 15-40 micron, minimum melting temperature as 240 C and minimum tensile strength of 300 Mpa and at the rate as specified by the manufacturer. PQC laid, spread and compacted with slip-form paver of minimum 7.50m width, including curing and tining by texturing cum curing machine complete all as specified and directed. Required surface texturing to be done as specified in clause 10.1.14 and table 9 of IRC 15-2017 complete all as specified and directed.

M&L for cutting of construction joints 25 mm deep and 10mm wide by early entry saw cut using diamond bit cutter of appropriate size, straight and smooth edges.Joint cleaned thoroughly with application of compressed air.Joint shall be made dry, vaccum cleaned and free of dirt ,oil,vegetation and oher debris .Application of two coats of primer with thin brush by forward and backward movement at an intervals of 30 minutes before placing the backup rod, and pouring the sealant .Placing of closed cell, medium density ,crossed linked polyethylene foam backup rod of 12mm dia, application of bond breaker tabe on top of backup rod for complete width of the joint and filled with polyurethane based sealant complying with BS-5212,BS 4254 and EN-141875-2003 with minimum movement accomodation factor (MAF) of +/- 30% having minimum 10 year performance guarantee, applying masked tape after of sealant as per the method specified by the manufacturer complete as specified and directed.

M&L for forming dummy/contraction joint with an initial saw cut of 3 mm soon after the concrete has set , upto a depth of 1/3rd to 1/4th the thicknesss of the slab, widening the first saw cut to 6 mm and 24 mm deep, by using diamond bit cutter of appropriate size, striaght and smooth edges, Joint cleaned thoroughly with application of compressed air, Joint shall be made dry , vacuum cleaned and free of dirt,oil, vegetation and other debris, application of two coats of primer with thin brush by forward and backward movement at an interval of 30 minutes before placing the backup rod and pouring the sealant, Placing of closed cell, medium density, crossed linked polyuthylene foam backup rod of 8 mm dia, application of boan breaker tape on top of back up rod for complete width of the joint and filled with polyuretane based sealant complying with BS-5212,BS 4254 and EN-141875-2003 with minimum movement accomodation factor (MAF) of +/- 30% having minimum 10 year performance guarantee applying masked tape after filing of sealant as per the method specified by the manufacturer complete as specified and directed.

M&L for racking out old existing sealant compound and back up rod of the existing joints 10 mm wide by special tools like cutting blades / machines, widening of joints by 2 mm by using joint cutting blades of appropriate size, straight and smooth edges. Joint cleaned thoroughly with application of compressed air.Joint shall be made dry, vacuum cleaned and free of dirt, oil, vegetation and other debris. Application of two coats of primer with thin brush by forward and backward movement at an interval of 30 minutes before pouring the sealant. There after filled closed cell, medium density, cross linked polyethylene foam backup rod of 12mm dia for complete length of the joint, over it to be filled with polyurethane joint sealant meeting the requirement mentioned in BS-5212, BS 4254 and EN-141875-2003 with minimum movement accommodation factor MAF of +/- 30% complete all as specified and directed.

M&L for racking out old existing sealant compound and back up rod of the existing joints 25 mm wide by special tools like cutting blades / machines, widening of joints by 2 mm by using joint cutting blades of appropriate size, straight and smooth edges. Joint cleaned thoroughly with application of compressed air. Joint shall be made dry, vacuum cleaned and free of dirt, oil, vegetation and other debris. Application of two coats of primer with thin brush by forward and backward movement at an interval of 30 minutes before placing the filler board and pouring the sealant. There after filled with pre-molded 25 mm thick compressible polyethylene closed cell type filler board as specified, over it filled with closed cell, medium density, cross linked polyethylene foam backup rod of 30mm dia for complete length of the joint. Finally filled with polyurethane joint sealant meeting the requirement mentioned in BS 5212, BS 4254 and EN-141875-2003 with minimum movement accommodation factor MAF of +/- 30% complete all as specified and directed.