Renovation of Academic and Administrative Building for Anusuchit Janjati Balika Vidyalaya under Chaibasa Block, West Singhbhum For the Year-2021-22

Amount

Making plinth protection 50mm thick of cement concrete(1:3:6) (1cement:3 coarse sand:6graded stone aggregate 20mm nominal size)over 75mm thick bed of dry brick ballast 40mm nominal size, well rammed and consolidated and grouted with fine sand, including necessary excavation,levelling and drressing and finishing the top soomth.

Providing designation 75 B brick work in C.M.(1 :6) in superstructure with approved quality of clean coarse sand of F.M. 2 to2.5 including providing 10 mm thick mortar joints cost of screening materials , scafolding , raking out joints to 15mm depth curing, taxes and royalty all complete as per building specification and direction of E/l.

Providing designation 125 mm thick reinforced designation 75 A brick work in C.M (1:4) in superstructure with approved quality of clean coarse sand of F.M. 2 to 2.5 including the cost of screening, carriage of materials , scafolding, raking out joints to 15 mm depth, curing, taxes and royalty ( but excluding the cost of reinforcement) all complete as per building specification and direction of E/l.

Providing and fixing 37 mm thick factory made PVC Door shutter, styles and rails made of PVC hollow extruded printed and laminated section having overall dimension 115 mm x 37 mm with wall thickness 2 mm (±0.2 mm) with inbuilt beading on one side, the styles and rails mitred cut and joint at corners by inserting 2 nos PVC profile reinforcement of size 75 mm x 200 mm long with cross section size of 28 mm x 30 mm having wall thickness 2 mm (± 0.2 mm). Styles, rails and reinforcements to be fusion welded together. Only hinge side vertical style to be reinforced with PVC profile reinforcement in full length. Printed and laminated PVC lock rail of size 110 mm x 37 mm having wall thickness 2 mm (± 0.2 mm) to be welded horizontally with the vertical styles afterinserting PVC profile reinforcement as in styles and rails, providing with PVC snap fit beading, panels of 100 x 20 mm printed & laminated and inserting 2 nos 6 mm dia bright steel rod horizontally with both side threaded and tightened with check nuts and washers complete, all as per manufacturer's specification and direction of engineer-in-charge.

Providing and Fixing factory made PVC door frame made of PVC extruded sections of size 75 mm x 53 mm, having wall thickness 2.0 mm (± 0.2 mm). Both verticalssides of the frame reinforced with PVC profile of cross section size 28 mm x 30 mm x 2 mm thickness (± 0.2 mm) and 75 mm x 200 mm long, including reinforcing both ends of the top frame with PVC profile. PVC Door Frame and PVC reinforcement profile to be mitred cut, jointed and fusion welded together, including providing and fixing 3 nos of 125 mm long stainless steel hinges to frame, fixing the frame with jamb with required nos & sizes of anchor dash fastener, all complete as per manufacturer's specification and direction of engineerin-charge.

Providing 12mm cement plaster (1:6) with clean coarse sand of F.M. 1.5 including screening, curing with all leads and lifts of water, scaffolding taxes and royalty all complete as per building specification and direction of E/l.

Providing 6mm thick cement plaster (1:4) in ceiling with clean coarse sand of F.M. 1.5 including screening, curing with all leads and lifts of water, scaffolding taxes and royalty all complete as per building specification and direction of E/l.

Providing and applying white cement based putty of average thickness 1 mm, of approved brand and manufacturer, over the plastered all surface to prepare the surface even and smooth complete.

Providing two coats of synthetic enamel paint of approved shade and make over steel surface including cleaning the surface thoroughly, scaffolding and taxes all complete as per building specification and direciton of E/l.

Dismantling old plaster and pointing in cement or lime and raking out joints to 15 mm. depth, watering and disposal of unserviceable materials with all leads all complete as per direction of E/l.

Providing and laying double charge 600x600mm size vitrified floor tiles in different size (thickness to be specified by the manufacture)with water absorption less than 0.08% and confirming to IS:4457:2007,of approved make in all course

Extra for cleaning the old surface by scraping the entire old white wash or colour wash including cost of scaffolding taxes all complete job as per direction of E/I.

Dismantling patent stone floor including stacking serviceable materials in countable stacks within 15M. lead and disposal of unserviceable materials with all leads all complete as per direction of E/l.

Providing and laying 6mm precast white glazed tiles in walls over 12mm cement mortar (1:3) and jointed with grey cement slurry flush pointed with white cement including rubbing, polishing and cost of curing, taxes and royalty all complete as per building specification and direciton of E/l.

Providing and laying rectified Glazed Ceramic floor tiles of size 300x300 mm or more (thickness to be specified by the manufacture of 1st quality conforming to IS : 15622, of approved make, in all colours, shades,except White, Ivory, Grey, Fume Red Brown, laid on 20 mm thick Cement Mortar 1:4 (1 Cement : 4 Coarse sand), jointing with grey cement slurry @ 3.3 kg/ sqm including pointing the joints with white cement and matching pigments etc.,complete.

Providing and laying 20 mm thick kotah stone slab flooring of approved size, texture and colour over 19mm thick base of lime morter (1:1:1) (lime putty : surkhi: coarse sand) laid over and jointed with grey cement slurry mixed with pigment to match the shade of slab including rubbing and polishing to granolithic finish with approved quality of carborandum stone including cost of curing, taxes and royalty all complete as per building specification and direction of E/I.

Providing and laying 20 mm thick kotah stone tiles in risers of steps, skirting and pillars of approved size, texture and colour laid over 12mm thick cement mortar (1:3) and jointed with grey cement slurry mixed with pigment to match the shade of the slab including rubbing to granolithic finish with approved quality of carborandum stone including cost of curing, taxes and royalty all complete as per building specification and direction of E/I.

Finishing walls with Premium Acrylic Smooth exterior paint with Silicone additives of required shade: 13.47.1 New work (Two or more coats applied @ 1.43 ltr/10 sqm over and including priming coat of exterior primer applied @ 2.20 kg/10 sqm)

Providing two coats of oil bound distemper of approved shade and make over a coat of cement primer over new surface including preparing the plastered surface by rubbing smooth with pumice stone or fine sand paper, applying putty wherever required, scaffolding, washing of floors and taxes all complete as per building specification and direction of E/l.

Painting with synthetic enamel paint of approved brand and manufacture of required colour to give an even shade :13.62.1 Two or more coats on new work over an under coat of suitable shade with ordinary paint of approved brand and manufacture

Providing and fixing aluminium work for doors, windows, ventilators and partitions with extruded built up standard tubular sections/appropriate Z sections and other sections of approved make conforming to IS: 733 and IS: 1285, fixing with dash fasteners of required dia and size, including necessary filling up the gaps at junctions, i.e. at top, bottom and sides with required EPDM rubber/neoprene gasket etc. Aluminium sections shall be smooth, rust free,straight, mitred and jointed mechanically wherever required including cleat angle, Aluminium snap beading for glazing / paneling, C.P.brass / stainless steel screws, all complete as per architectural drawings and the directions of Engineer-in-charge. (Glazing, panelingand dash fasteners to be paid for separately) :Powder coated aluminium (minimum thickness of powder coating 50 micron)

For shutters of doors, windows & ventilators including providing and fixing hinges/ pivots and making provision for fixing of fittings wherever required including the cost of EPDM rubber / neoprene gasket required (Fittings shall be paid for separately)

Providing and fixing glazing in aluminium door, window, ventilator shutters and partitions etc. with EPDM rubber / neoprene gasket etc. complete as per the architectural drawings and the directions of engineer-in-charge . (Cost of aluminium snap beading shall be paid in basic item):With float glass panes of 5 mm thickness (weight not less than 12.50 kg/sqm)

Filling the gap in between aluminium frame & adjacent RCC/ Brick/Stone work by providing weather silicon sealant over backer rod of approved quality as per architectural drawings and direction of Engineer-in-charge complete.21.8.1 Upto 5mm depth and 5 mm width

Providing and fixing IS : 12817 marked stainless steel butt hinges (heavy weight) with stainless steel screws etc. complete :100x60x2.50mm

Stainless steel screws 30mm(1.5")

Providing and fixing bright /matt finished Stainless Steel handles of approved quality & make with necessary screws etc all complete.100mm

Providing and fixing bright finished brass tower bolts (barrel type) withnecessary screws etc. complete :150x10 mm

Providing and fixing bright finished brass door latch with necessary screws etc. complete :250x16 x5mm

Taking down old door and window shutters including stacking serviceable materials within 15M. lead and disposal of unserviceable materials with all leads all complete as per direciton of E/l.

Taking down chowkhat in doors including stacking serviceable materials within 15M. lead and disposal of unserviceable materials with all leads all complete as per direciton of E/l.

Providing and fixing factory single extruded WPC(wood polymer composite)solid door/window/ ceosetory windows and other frames/chowkat comprising of virgin PVC polymer of K value 58-60(suspension grade)calcium carbonate and natural fibers (wood powder/rice husk/wheat husk)and non toxic additives (maximum tixicity index of 12 for 100gms) fabricated with miter joints after applying PVC solvent cement and screwed with full body threaded frame size 50x100mm

Providing and fixing factory made single extruded WPC (Wood Polymer Composite) solid plain flush door shutter of required size comprising of virgin polymer of K value 58-60 (Suspension Grade), calcium carbonate and natural fibers (wood powder/ rice husk/wheat husk) and non toxic additives (maximum toxicity index of 12 for 100 gms) having minimum density of 650 kg/cum and screw withdrawal strength of 1800 N (Face) & 900 N (Edge), minimum compressive strength 50 N/mm2, modulus of elasticity 850 N/mm2 and resistance to spread of flame of Class A category with property of being termite/ borer proof, water/moisture proof and fire retardant and fixing with stainless steel butt hinges of required size with necessary full body threaded star headed counter sunk S.S screws, all as per direction of Engineer-In- Charge. (Note: stainless steel butt hinges and necessary S.S screws shall be paid separately)30mm thick

Providing and laying APP (Atactic Polypropylene Polymer) modified prefabricated five layer 3 mm thick water proofing membrane, black finished reinforced with non-woven polyester matt consisting of a coat of bitumen primer for bitumen membrane @ 0.40 litre/sqm by the same membrane manufacture of density at 25°C, 0.87-0.89 kg/ litre and viscocity 70-160 cps. Over the primer coat the layer of membrane shall be laid using Butane Torch and sealing all jointsetc, and preparing the surface complete. The vital physical and chemical parameters of the membrane shall be as under : Joint strength in longitudinal and transverse direction at 23°C as 650/ 450N/5cm. Tear strength in longitudinal and transverse direction as 300/250N. Softening point of membrane not less than 150°C. Cold flexibility shall be upto -2°C when tested in accordance with ASTM,D - 5147. The laying of membrane shall be got done through the authorised applicator of the manufacturer of membrane : 14.91.1 3 mm thick Extra for covering top of membrane with Geotextile, 120 gsm non woven, 100% polyester of thickness 1 to 1.25 mm bonded to the membrane with intermittent touch by heating the membrane by Butane Torch as per manufactures recommendation.

Providing 12mm thick water proof cement plaster (1:3) with clean coarse sand of F.M. 1.5with 5% cico or any other approved water proofing compoundincluding taxes and royalty all complete as per building specification and direction of E/l.

Providing P.C.C.M - 150 with nominal mix of (1:2:4) in foundation with approved quality of stone chips 20 mm to 6mm size graded and clean coarse sand of F.M. 2.5 to 3 including screening, shuttering, mixing cement concrete in mixer and placing in position, vibrating, striking, curing, taxes and royalty all complete as per building specification and direction of E/l.

Taking down ceiling of any type and refixing them after repair with departmental material within 15M lead and disposal of unserviceable materials with all leads all complete as per direction of E/l.

Providing R.C.C.M - 200 with nominal mix of (1:1.5:3) in chajja with approved quality of stone chips 20 mm to 6 mm size graded and clean coarse sand of F.M 2.5 to 3 including screening, centering, shuttering, mixing cement concrete in mixer and placing in position, vibrating, striking, curing (but excluding the cost of reinforcement) taxes and royalty all complete as per building specification and direction of E/l.

Centering and shuttering in chajja proping all complete job as per direction of E/I.

Providing Tor steel reinforcement of 10mm. ,12mm & 16mm dia. bars as per approved design and drawing excluding carriage of M.S. bars to work site , cutting, bending and binding with annealed wire with cost of wire, removal of rust placing the rods in position all complete as per building specification and direction of E/l.

Providing and fixing on wall face unplasticised Rigid PVC rain water pipes conforming to IS : 13592 Type A, including jointing with seal ring conforming to IS : 5382, leaving 10 mm gap for thermal expansion, (i) Single socketed pipes. 110mm dia

Providing and fixing on wall face unplasticised - PVC moulded fittings/ accessories for unplasticised Rigid PVC rain water pipes conforming to IS : 13592 Type A, including jointing with seal ring conforming to IS : 5382, leaving 10 mm gap for thermal expansion.

110mm coupler

110mm bend

110mm shoe

Providing and fixing unplasticised -PVC pipe clips of approved design to unplasticised - PVC rain water pipes by means of 50x50x50 mm hard wood plugs, screwed with M.S. screws of required length, including cutting brick work and fixing in cement mortar 1:4 (1 cement : 4 coarse sand) and making good the wall etc. complete.110mm

Chequerred precast cement concrete tiles 22 mm thick in footpath & courtyard jointed with neat cement slurry mixed with pigment to match the shade of tiles including rubbing and cleaning etc. complete on 20 mm thick bed of cement mortar 1:4 ( 1 cement 4 coarse sand )

Dismantling R.C.C.work including stacking serviceable materials in countable stacks within 15M. lead and disposal of unserviceable materials with all leads all complete as per direction of E/l.

Supplying, fitting and fixing M.S. grill made of 20x6mm M.S. flat as per approved design and drawing, properly fabricated with joints continuous fillet welded and finished smooth , carriage of grill to work site, hoisting as per building specification and direction of E/l. (where materials is not supplied by the deptt.)

Supplying, fitting and fixing callapsible gate of approved size and make properly fabricated with vertical double channels 20 x 10 x 2 mm at 100mm. centres and braced with M.S. flat diagonals 20 x 3mm with top and bottom rails of T.iron 40x40x6mm with 38mm dia steel pulleys complete with bolts, nuts, locking arrangements, stoppers, handles, including applying a priming coat of red lead paint, carriage , hoisting and taxes all complete as per building specification and direction of E/l.

Steel work welded in built up sections/ framed work, including cutting,hoisting, fixing in position and applying a priming coat of approved steel primer using structural steel etc. as required. In gratings, frames, guard bar, ladder, railings, brackets, gates and similar works

Structural steel work riveted,bolted or welded in built up sections, trusses and frame work including cutting hoisting fixing in position and applying a pri8ming coat of approved steel primer all complete job as per direction of E/I.

Providing and fixing precoated galvanised iron profile sheets (size, shape and pitch of corrugation as approved by Engineer-in-charge) 0.50 mm (+ 0.05 %) total coated thickness with zinc coating 120 grams per sqm as per IS: 277, in 240 mpa steel grade, 5-7 microns epoxy primer on both side of the sheet and polyester top coat 15-18 microns. Sheet should have protective guard film of 25 microns minimum to avoid scratches during transportation and should be supplied in single length upto 12 metre or as desired by Engineerin- charge. The sheet shall be fixed using self drilling /self tapping screws of size (5.5x 55 mm) with EPDM seal, complete upto any pitch in horizontal/ vertical or curved surfaces, excluding the cost of purlins, rafters and trusses and including cutting to size and shape wherever required.

Providing and fixing precoated galvanised steel sheet roofing accessories 0.50 mm (+0.05 %) total coated thickness, Zinc coating 120 grams per sqm as per IS: 277, in 240 mpa steel grade, 5-7 microns epoxy primer on both side of the sheet and polyester top coat 15-18 microns using self drilling/ self tapping screws complete :

Ridges plain(500-600mm)neter 416.30

Flashing/Aprons(Upto 600mm)

Gutter(600mm over all girth)

Carriage of materials from nearest approved sources of supply including loading intro trucks and unloading from trucks and stacking properly at work site as directed by the E/I.

Sand lead(1K+8P) 9Km

Stone chips lead(1K+7P) 8Km

Brick lead (1K+7P)8Km

Providing and fixing male ended 15mm dia brass bib cock of approved quality (wt.not less than 350gms)with extra socket all complete as per specification and direction of E/I.

Providing and fixing 15mm size pillar cock C.I.body brass spindle pillar cock of approved quality as per specification and direction of E/I.

Providing and fixing brass/C.I.stop cock of approved quality all complete job as per direction of E/I. 15mm dia

Providing and fixing G.M. non Return valve Horizontal/ vertical type of approved quality as per specification and direction of E/I.

Horizontal-25mm dia

Horizontal-32mm dia

Making holes in wall for laying G.I.pipe and restoring the same after pipe laying as per specification and directionof E/I.

125mm thick wall

250mm thick wall

Supplying fitting and fixing the following items complete with all materials as per specification and direction of E/I.

Mirror (300x450mm)

C.P.brass Towel Rail

C.P.brass soap container medium quality with screws and hinges etc.

Supplying fitting and fixing vitreous white glazed earthen ware I.W.C.-do-do-all complete job as per direction of E/I. 580mm long with 12.5 liter low level Cistern.

(c) with 12.5 lit. low level P.V.C. cistern

Supplying fitting and fixing 40mm high vitreous white glazed earthen ware EWC -do-do-all complete job as per direction of E/I.

Supplying fitting and fixing vitreous white glazed earthen ware wash hand basin-do-do-all complete job as per direction of E/I.

Supplying NP2 R.C.C.hume pipe with colour as work site as per direction of E/I. 150mm dia

Special type of C.P.Bath roof fittings for V.I.P. buildings(JAL,JAGUAR,MARC or equivelent mark)

Angular stop cock/2 way bib cock

Telephonic Shower flexible pipe

Providing and fixing on wall face unplasticied Rigid PVC rain water pipes conforming to IS:13592 Type A , including jointing with seal ring conforming to IS:5382leaving 10mm gap for thermal expansion (i)single socketed pipes

75mm dia meter

110mm diameter

Providing and fixing on wall face unplasticised - PVC moulded fittings/ accessories for unplasticised Rigid PVC rain water pipes conforming to IS : 13592 Type A, including jointing with seal ring conforming to IS : 5382, leaving 10 mm gap for thermal expansion.

Single Tee without door 75x75x75mm

Single Tee without door 110x110x110mm

75mm dia Bend

110mm dia Bend

Providing and fixing Chlorinated Polyvinyl Chloride (CPVC) pipes,having thermal stability for hot & cold water supply, including all CPVC plain & brass threaded fittings, including fixing the pipe with clamps at 1.00 m spacing. This includes jointing of pipes & fittings with one step CPVC solvent cement and testing of joints complete as per direction of Engineer in Charge.

25mm nominal outer dia pipe

32mm dia nominal outer dia pipe

Providing and fixing Chlorinated Polyvinyl Chloride (CPVC) pipes,having thermal stability for hot & cold water supply, including all CPVC plain & brass threaded fittings, i/c fixing the pipe with clamps at 1.00 m spacing. This includes jointing of pipes & fittings with one step CPVC solvent cement and the cost of cutting chases and making good the same including testing of joints complete as per direction of Engineer in Charge. Concealed work, including cutting chases and making good the walls etc.

15mm dia nominal outer dia pipe

20mm dia nominal outer dia pipe

Polythene water storage tank of ISI mark (e.g. sintex/Sinter/ Himgiri etc.) with cover and locking system.

Point wiring in PVC conduit with piano type switch:- Wiring for light point/exhaust fan point/call bell point with 1.5Sq.mm FRPVC insulated copper conductor single core cable in surface/recessed PVC conduit with Piano type switch,Phenolic laminated sheet,suitable size PVC/G.I.box etc.as required.

Group C

Twin control point wiring in PVC conduit with piano type switch:- Wiring for twin control light point with 1.5Sq.mm FRPVC insulated copper conductor single core cable in surface/recessed PVC conduit, 2way piano type switch,phenolic laminated sheet sheet,suitable size PVC/G.I.box etc.as required.

Power plug wiring in PVC conduit(2x4Sq.mm) Wiring for light/power plug with 2x4Sq.mm FRPVC insulated copper conductor single core cable in surface or in recessed PVC conduit along with 1No4Sq.mm FRPVC insulated copper conductor single core cable for loop earthing etc. as required.

Circuit/submain wiring PVC conduit:- Wiring for circuit/submain withing along with earth wire with the following sizes in PVC insulated copper conductor single core cable in surface/ recessed PVC conduit as required.

2x1.5Sq.mm+1x1.5Sq.mm earth wire

2x2.5Sq.mm+1x2.5Sq.mm earth wire

4x6Sq.mm+2x6Sq.mm earth wire

S/F piano type switch/socket:- Supplying and fixing of following piano type switch/socket on the existing switch box/cover including connection etc.as required.

5/6Amp one way switch

3Pin 5/6Amp socket outlet

Electronic step fan regulator,deluxe

S/F light plug point with piano type Accessories:- Supplying and fixing suitable size G.I./PVC box on surface or in recess with phenolic laminated sheet cover infront including providing and fixing 5Pin 5/6Amp socket outlet and 5/6Amp piano type switch connection, painiting etc.as required.

S/F light plug point with piano type Accessories:- Supplying and fixing suitable size G.I./PVC box on surface or in recess with phenolic laminated sheet cover infront including providing and fixing 6Pin 15/16Amp modular socket outlet and 15/16Amp modular type switch connection, painiting etc.as required.

Supplying and fixing 2pin ceiling rose on the existing junction box/wooden block including connection etc.as required.

Supplying and fixing batten/angle holder including connection etc.as required.

Installation Testing and commissioning of pre-wired fluorescent fittings/ compact fluroescent fitting all type complete with all accessoires and tubes etc.directly/wall including connection witgh 1.5Sq.mm FRPVC insulated copper conductor single core cable and earthing etc.as required.

Installation Testing and Commissioning of ceiling fan, including wiring the down rods of standard length (upto 30cm)with 1.5Sq.mm FR PVC insulated copper conductor, single core cable etc.as required.

Installation Testing and commissioning of exhaust fan upto 450mm sweep in the existing opening including making the hole to suit the size of the above fan,making good the damage,connection,testing,commissioning etc.as required.

Providing and fixing following capacity double pole/TP&N sheet metal switch disconnector fuse unit in the existing metal with rewireable type fuses including drilling holes in metal board making connection etc.as required.

63Amp double pole

Providing and fixing following capacity busbar chamber with 4strips of length 300mm made of copper suitable for following capacity complete with all accessories including connection edarthing the bodey etc. as required. 100Amp

Supplying and fixing following way single pole neutral,sheet,MCB distribution board 240Volts,on surface/recess-do-do-all complete job as per direction of E/I.8Way single door

Supplying and fixing 6Amp to 32Amp rating 240Vls 10KA,"B" Series miniature circuit breaker suitable for inductive load of following poles in the existing MCB DB complete with connections testing and commissioning etc.as required.

6/32Amp single pole"B" Series

Supplying and fixingv following rating double pole 240V ,Isolator in the existing MCBDB complete with connection,testing and commissiong etc.as required.

63Amp double pole

Earthing with G.I.earth pipe 4.5meter long 50mm dia including accessories and providing masonarty enclosure with cover plate having -do-do-all complete job as per direction of E/I.

Supplying and laying 8SWG copper wire at 0.50M below ground level for conductor earth icnlduing sholdering etc.as required.

Providing and fixing of lightning conductor sinal made of 25mm dia 300mm long copper tube having single prong at top with 85mm dia 3mm thick copper base plate base including holes etc.complete as required.

Providing and fixing copper taper 20x3mm thick on parapet or surface of wall for lighting conductror complete as required(For Horizontal run)

Providing and fixing copper taper 20x3mm thick on parapet or surface of wall for lighting conductror complete as required(For vertical run)

Laying of one number PVC insulated and PVC sheathed.XLPE power cable of 1.1Kv grade of size exceeding 25Sq.mm but not exceeding 120Sq.mm direct in ground including excavation sand cushioning,protective covering and refilling the trenches etc.as required.

Providing and fixing of XLPE aluminum Armoured PVC cable conforming to IS 7908(Part-I)1988 of grade 1.1KV make Havles/Finolex/Polycab. 3.5core 35Sq.mm

Laying of Med class G.I.pipes earth cutting excavation and refilling and making the surface smooth

Supply of 9/10 watt LED blub

Supply of LED batten (20/22W)

Recess mounting LED LED Round down light (18/20W)

Supply LED Street light(45/48W)

Supply and Installation of ceiling fan 48"(1200mm)

Supplying fitting and fixing and testing of 9" (230mm)metal exhaust fan.

Add 12 % GST (in Basic Rate must fill 12)

Add 1% Labour Cess (in Basic Rate must fill 1)

M/S RAJEEV KUMAR