URGENT REPAIR /REPLACEMENT OF RIGID AND FLEXIBLE RUNWAY AT ALG ZERO

Dismantling and bracking ,Cutting of old pavement quality concrete of flexural strength 40 kg/sqm or more upto full depth in tarmac by mechanical method using diamond cutter machine to separate the dismantled portion slab from existing slab and then dismantling of slab by mechanical method, without disturbing surrounding tarmac and cleaning the cutting area of tarmac and disposed rubbish outside the MOD land.complete all as specified and directed. Note : (a) Demolition shall be done by mechanical means using diamond cutter machine to isolate the poertion to be dismantled. (b) Demolition of slab to be done without disturbing the adjacent slabs as specified and directed. (c) Initial level survey to be carried out, along with MES rep before cutting/demolition of slab portion. (d) Any damage to adjacent concrete pavement has to be rectified without extra cost or on contractors risk of cost.

Providing and laying dry lean concrete (DLC), (as in Runway rigid ) of 100mm thick of aggregate gradation as per Table 1 of SP 49.2014 having 7 days average compressive strength not less than 7 Mpa. Minimum cement content not less than 140 Kg/Cum DLC mixed in batching plant, transported to site and laid using Mechanical paver or mechanical screeding as per site condition , including spreading and compacting using high amptitute tamping bars of paver (initial compaction) further by double drum smooth wheeled vibratory rollers with 80-100 KN static weight to achieve minimum dry density not less than 98% of maximum Dry density, necessary finishing etc complete all as specified and tolerances to be as per Table 900-1 of Morth specification for road and bridge work 2013. as specified and directed by Engineer in charge. Note:1.Method of laying shall be adopted based on patch size and operational constraints as per IRC:15-2011 para 10.2

M & L for Pavement quality concrete (PQC) of minimum 28 days field Flexural strength of 45Kg/ 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 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 from paver of minm 7.50 m width including supply and fixing of required formwork, non-circular virigin synthetic fibre and 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 Note :(1).Casting to be done as per initial survey as directed by Engr-in-Charge. (2).Method of laying shall be adopted based on patch size and operational constraints as per IRC:15-2011 para 10.2. (3). No construction joints admissible, individual slab panel of approx 16 sqm each to be casted in one go for DLC and PQC respectively.

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 as directed.

Supply and laying Polythene film 400 micron thick HDPE Sheet (Virgin Quality) waterproof wrinkle free without puncture having minm weight 390 gm/Sqm over sand cushion with overlap between adjacent strips, Joints and ends as minimum 300mm complete all as specified and directed.(No additional amount to be paid for overlap)

M&L for Finishing surface of concrete roads, pavements, by brooming,complete all as specified and and directed .

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 thickness of the slab, widening the first saw cut to 6 mm and 24 mm deep by using diamond bit cutter 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 backup rod and pouring the sealant. Placing of closed cell, medium density, crossed linked polyethylene foam backup rod of 8 mm dia and application of bond breaker tape on top of back up 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 accommodation factor (MAF) OF +/- 30% having minimum 10 year performance guarantee applying masked tape on the edges of joints and removing the masking tape after filling of sealant as per the method specified by the manufacturer complete as specified and directed.

Forming 20 to 25 mm width expansion joint in concrete slab for full depth of PQC. Early entry saw and subsequent cutting by using diamond bit cutter or appropriate size. straight and smooth edges. Join cleaned thoroughly with application of compressed air. Joint shall be made dry, vacuum cleaned and free of dirt, oil , vegetation and other debris. The jointhen filled with pre-molded 25 mm thick compressible polyethylene closed cell type filler board as specified thereafter 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 polyethylene foam backup rod of 30 mm dia, over filler board and filled with polyurethane based sealant complying with BS- 5212, BS 4254 and EN-141875-2003 with minimum movement accommodation factor (MAF) of+/- 30% having minimum 10 year performance guarantee applying masked tape on the edges of joints and removing the masking tape after filling of sealant as per the method specified by the manufacture complete as specified and directed

Cutting of construction joints 25 mm deep and 10 mm 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, vacuum cleaned and free of dirt, oil, vegetation and other debris. Application 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 polyethylene foam backup rod of 12 mm dia, application of bond breaker tape on top of back up rod for complete width of the joint and filled with polyurethane based sealant complying with BS-5212, BS 4254 and EN-14187-5-2003 with minimum movement accommodation factor (MAF) of +/- 30% having minimum 10 year performance guarantee, applying masked tape on the edges of joints and removing the masking tape after filling of sealant as per the method specified by the manufacturer complete as specified and directed

Demolition of bituminous concrete of any description and in any position of RUNWAY using mechanical methods like cold milling, hydraulic breaker, excavator or dozer, hand breaker complete all as specified and directed by Engineer in Charge. Note : (a) Removing of demolished material as per schedule of credit.. (b) Demolition of DAC layer and DBM layer to be done by mechanical method, without disturbing sorrounding, adjacent bituminius concrete pavment. (c) Cleaning the demolished area (d) Initial level survey to be done before cutting/demolition of flexible layer. (e) Any damage of adjacent layers to be rectified without extra cost or on contractors own risk of cost.