TOYO ENGINEERING INDIA LIMITED

Transcription

1 ENGINEERING SPECIFICATION FOR WATER PROOFING WORK FOR NITROGEN UNIT FOR HINDUSTAN PETROLEUM CORPORATION LTD. VISAKH REFINERY DHT PROJECT JOB NO. : 6261 DOCUMENT NO. : A TOTAL NO. OF PAGES: 13 (INCLUDING THIS PAGE) FOR BID ENQUIRY AGR SVP RCN REV. DATE DESCRIPTION MADE BY CHECKED APPROVED TOYO ENGINEERING INDIA LIMITED MUMBAI INDIA

2 ISSUED: CIVIL DESIGN DEPARTMENT PAGE 2 OF 13 CONTENTS PARA NO. DESCRIPTION PAGE NO. 1.0 SCOPE APPLICABLE CODES PRIORITY OF REQUIREMENTS BITUMEN FELT BASED WATER PROOFING Surface preparation Treatment Method of laying Application areas Manufacturers CEMENT BASED WATER PROOFING Integral Water Proofing Compounds Surface Method Sodium Silicate Treatment Brick Bat Coba Treatment Box Type Method Injection and Grouting Method Applications Manufacturers POLYURETHANE WATER PROOFING Materials Workmanship Guarantee 13

3 ISSUED: CIVIL DESIGN DEPARTMENT PAGE 3 OF SCOPE This specification covers the requirement of various water proofing treatment for water proofing of various components of structures in the buildings, Civil works i.e. roofs, basements, water tanks, trenches etc. This specification covers supply of labour, material, construction aids, tools and tackle etc. for water proofing and damp proofing. 2.0 APPLICABLE CODES Note: Wherever reference is made to IS Codes, on any page of this Technical Specification (including annexures), applicable year of publication of IS Code is as stated below. The following codes applicable to this section shall include but not limited to the following: IS: IS: : IS: : IS: : IS: : IS: IS: : IS: IS: : IS: : IS: IS: : IS: IS: : : Industrial bitumen. Specification for bitumen felts for water proofing and damp proofing. Code of practice for waterproofing of roofs with bitumen felts. Specifications for bituminous compounds for water proofing and caulking purpose. Code of practice for laying damp proof treatment using bitumen felt. : Integral cement waterproofing compounds. Code of practice for laying lime concrete for waterproof roof finish. : Bitumastic for use in waterproofing of roofs. Code of practice for general design, details and preparatory work for damp-proofing and water-proofing of building. Broken brick (burnt clay) coarse aggregate for use in lime concrete. : Bitumen primer for use in waterproofing and damp proofing. Code of practice for application of bitumen mastic for water proofing of roofs. : Bitumen mastic for tanking and damp proofing. Code of practice for water proofing of underground water reservoirs and swimming pools.

4 ISSUED: CIVIL DESIGN DEPARTMENT PAGE 4 OF PRIORITY OF REQUIREMENTS In case of any variation and discrepancy in condition between the special conditions, this specification and codes, order of priority shall be as under :- (1) Special conditions (2) This specification (3) Codes 4.0 BITUMEN FELT BASED WATER PROOFING The waterproofing work shall be carried out by LSTK CONTRACTORS who have experience in doing waterproofing work and shall give a guarantee on a stamped paper for good performance of the waterproof treatment for a minimum of seven years period and shall, at their own cost, rectify the defects if any found during the guarantee period. If approved by the Engineer-In-Charge, in-situ fiberglass tissue reinforced bitumen layers equivalent to bitumen felt may be used. 4.1 Surface preparation Any cracks in the surface (other than hair cracks) shall be cut to V-shape, cleaned and filled with cement mortar 1:2 or with bitumen conforming to IS 702, as directed by the Engineer-In-Charge. All fungus growth, moss, dust shall be removed by wire brushing. When, a pipe passes through R.C.C. slab a cement concrete fillet shall be built around the pipe and waterproofing taken over the fillet. In brick parapet walls, a chase shall be made in the parapet wall to terminate the bitumen felt. No chase shall be made in the R. C. C. parapet walls. 4.2 Treatment Treatment shall consist of one of the following as specified, in the drawings or as instructed by the Engineer-In-Charge Four Course Treatment (a) Normal Treatment (i) Hot bitumen applied at the rate of 1.2 kg/m 2 (ii) Hessian based self-finished felt, type 3, grade 1. (iii) Hot bitumen applied at the rate of 1.2 kg/m 2 (iv) of Pea-sized gravel or grit at the rate of 0.006m 3 /m 2 or (if specified) 2 coats bituminous aluminum paint.

5 ISSUED: CIVIL DESIGN DEPARTMENT PAGE 5 OF 13 (b) Floating Treatment (i) Fiber-base bitumen saturated underlay, type 1 (ii) Hot bitumen applied at the rate of 1.2 kg/m 2 (iii) Fiberglass self-finished felt type 2, grade 2. (iv) Hot bitumen applied at the rate of 1.2 kg/m 2 (v) Pea-size gravel or grit at the rate of m 3 /m 2 or (if specified) 2 coats of bituminous aluminium paint Seven Course Treatment (a) Floating Treatment (i) Bitumen primer at rate 0.08 lit/m 2 (ii) Hot bitumen applied at the rate of 1.2 kg/m 2 (iii) Fiber based felt type 2, grade 2 or Hessian based felt type 3, grade 1. (iv) Hot bitumen applied at the rate of 1.2 kg/m 2 (v) Fiber based felt type 2, grade 2 or hessian based felt type 3, grade 1. (vi) Hot bitumen applied at the rate of 2.5 kg/m 2 and 1.5 kg/m 2 for felt and hessian respectively. (vii) Pea-sized gravel or grit at the rate of 0.008m 3 /m 2 or (if specified) 2 coats bituminous aluminium paint. (b) Floating Treatment (i) Fiber-based felt saturated underlay, type 1 (ii) Hot bitumen applied at the rate of 1.2 kg/m 2 (iii) Fiber-based felt type 2, grade 2 (iv) Hot bitumen applied at the rate of 1.2 kg/m 2 (v) Fiber based felt type 2, grade 2 (vi) Hot bitumen applied at the rate of 2.5 kg/m 2 (vii) Pea-sized gravel or grit at the rate of 0.008m 3 /m 2 or (if specified) 2 coats of bituminous aluminium paint.

6 ISSUED: CIVIL DESIGN DEPARTMENT PAGE 6 OF Method of laying The felt shall be laid in length, at right angles to the gradient, commencing at the lowest level and working up to the crest. The felt shall be cut to required lengths, brushed clean of dusting material, laid out flat on the roof to eliminate curls. It shall be laid in position and rolled up for a distance of half its length. The hot bonding material shall be poured onto the roof, across the full width of the rolled felt, as the latter is steadily rolled out and pressed down. The excess bonding material shall be squeezed out, at the ends and shall be removed as the laying proceeds. When the first half of the strip of felt has been bonded to the roof, the other half shall be rolled up and then unrolled onto the hot bonding material in the same way as described above. Minimum end and side overlaps shall be 100mm and 75mm respectively. All overlaps shall be firmly bonded with hot bitumen. Laying of the second layer shall be so arranged that the joints between the first and second layer are staggered. At the junction of vertical and horizontal, flashing of bitumen felt with minimum overlap of 100mm shall be provided. The grooves in the parapet wall shall be filled with cement mortar 1:2 after completing fixing of felts. Any ballooning observed shall be rectified. 4.4 Application areas Building roofs (a) (b) Membrane water proofing based on bitumen felt laying procedure as described in 4.1, 4.2, and 4.3 above. Multiplas, a prefabricated multilayered sandwich of polythene and polymeric asphalt, product of Spannish water proofing may be used, if specified by Engineer-In-charge. Multiplas Standard membrane is suitable for roofs and sunken portion of toilets. Application of multiplas is fast and easy. Surface shall be cleaned and prepared smooth to receive membrane. Surface is then coated with special Multiplas Primer. Blown Bitumen shall be filled in the surface pores to improve adhesion. Rolls of Multiplas shall be unrolled at site. Adjacent sheets shall be lapped by 100 mm. Entire membrane is fused of substrate by means of blowlamp torch from a homogeneous watertight layer on the surface. The system is finally protected with mechanical topping such as cement plaster/ tiles to provide a traversible and usable surface Toilet (Sunken Portion), As in (a) and (b) above

7 ISSUED: CIVIL DESIGN DEPARTMENT PAGE 7 OF Underground Water Proofing This specification covers the requirements of water proofing of basements, tunnels, ducts, pits, bunkers, trenches, etc. The material used shall be bitumen felt Type-3 of Grade-2 conforming to IS 1322, together with the specified bonding material and primer. The number of layers of bitumen felt to be used for walls and floor, shall be as per the drawings. The method of laying the bitumen felts and workmanship shall in general conform to IS Water proofing work shall be taken in hand only when the site sub-soil water level is at its lowest. The site shall be kept dry by adequate arrangements for pumping out water till the work has been completed. For this purpose drains shall be formed along the edges of the excavation but beyond the building line, with suitable collecting sumps, in case of large excavation, to adequately drain the area. Adequate arrangement shall be made to prevent the sides of excavation from slipping when the work is in progress. The base concrete or mud-mat shall be rendered smooth by a 20mm thick cement sand plaster (1:6). Any sharp corner over which the waterproofing course is to be laid shall be eased out by means of cement mortar fillets 75mm in radius. The surface shall be dried before the next operation is carried out. Blown bitumen conforming to IS 702 shall be applied hot over the prepared surface at the rate of 2 kg/m 2 for the first layer and 1.6 kg/m 2 for every other subsequent layer(s). The laying of felt over the bitumen so applied shall always commence on the floor and shall be carried out over the walls only after treatment of the floor is complete. The minimum over lapping of joints for subsequent layers of felt shall be 150mm. Joints for subsequent layers of felt shall be staggered. All joints shall be completely sealed by blowlamp. A protective flooring of either brick bat in cement mortar 1:3 or 60mm thick cement concrete of grade M-15 or a coat of cement plaster (1:3) 4mm thick on 25 to 30mm thick cuddapah stone set in 1:2 cement mortar with 2% by weight of cement water proofing compound CICCO No. 1 or approved equivalent, joints flush pointed with same mortar, shall be constructed over the bitumen layers to prevent damage to later during subsequent construction of the Structural floor. The walls shall be treated in a similar way, the bitumen felts joining at the base with the projecting felt over the mud-mat. The wall surface shall be made smooth, where necessary with a coat of cement plaster 1:3. The felt shall be laid as for the floor, ensuring that the surface to be treated is dry and then a protective brick wall 115mm nominal, thickness shall be built in cement mortar

8 ISSUED: CIVIL DESIGN DEPARTMENT PAGE 8 OF 13 1:3 over the projecting mud mat. The space between the wall and felt shall be grouted with cement slurry. The treatment on the wall shall be carried 150cm above the surface of ground and tucked into a groove 65mm wide and 40mm deep, the chase being filled with cement mortar (1:4) Where water proofing is done to the roof of an underground structure, such as a tunnel, it shall be done in a similar way. The structural concrete shall be rendered smooth, hot bitumen and bitumen felts applied on the same way as for the floor, walls and over this a protective layer of cement concrete grade M-15, 75mm thick shall be laid. The LSTK CONTRACTOR shall guarantee the water tightness and water proofness of the structure for a period of 10 years. The work shall be done by a firm of specialists in the trade approved by Engineer-In-charge. 4.5 Manufacturers Bitumen felts Hessian based, polymeric bitumen primer etc. products are available from following Manufacturers Shalimar Tar Products - STP Ltd. - Bitumen felt etc M/S American Roofing Systems Pvt. Ltd. - SWEPCO Products for roof, wall and floors etc F.G.P. Ltd. Fiber Glass Reinforced Plastic products - for bitumen felt F.G.P. based for item above Spanish Water Proofing Co. - mulitplas Products - Multiplas standard used for water proofing for item 4.4.1, above - Multiplas aluminum used for water proofing for item above where water proofing with heat insulation is required. - Multiplas hiper used for water proofing of item where mechanical strength is required. Note: Manufacturers specifications for the above products shall be referred and Engineer-In-charge s approval shall be taken prior to its use in works. 5.0 CEMENT BASED WATER PROOFING Various methods such as Integral Water Proofing, Surface Method, Box Type Method, Injection and Grouting Method are used in Cement Based Water Proofing. 5.1 Integral Water Proofing In this method, chemicals shall be used during construction, with the objective of water proofing and Dam proofing of concrete structure. Integral Water Proofing Compounds (IWPC) i.e. plastizers and additives etc. shall be used to make

9 ISSUED: CIVIL DESIGN DEPARTMENT PAGE 9 OF 13 concrete impermeable to water, ensuring water tightness of structural components, so as to avoid corrosion of reinforcement inside. Use of suitable plastizers, makes the concrete mix homogenous, cohesive and workable, easy for placing and compaction. Bleeding and segregation is avoided. IWPC shall be used in foundation mortar, brick/ stone masonry mortar/ plaster. DPC at the plinth shall contain IWPC, that would not allow water to enter the wall above plinth, in concrete for various components of structure i.e. columns, beams, slabs etc. IWPC shall be used in concrete in water tanks, either underground or overhead. 5.2 Surface method The treatment shall be laid over the slab R.C.C. slab, the detailed operations are as follows: After the R.C.C. slab has been cleaned, slurry coat consisting of the neat cement admixed with specialized imported acrylic based chemicals (or sodium silicate treatment described below), which penetrates in the minutes of crevices and fill up all the porosity in the structure, shall be used. In case of construction joints between different R.C.C. members the, chemicals mixed with neat cement slurry shall be injected at joints to make them monolithic A layer consisting of half cut brick in cement mortar 1:5 (1 cement: 5 coarse sand), admixed with acrylic based chemicals laid to necessary gradient for proper flow of water towards the drains. The treatment shall be extended up to 300mm height of parapet walls also. The average thickness of this brick bat coba shall be 120mm with a minimum thickness of 75mm at the drain. After a proper curing for about 3 days, slurry coat consisting of cement slurry mixed with water proofing chemicals is provided to fill in the joints The top is then finished smoothly with cement mortar 1:4 (1 cement: 4 coarse sand), with acrylic based chemicals with 300 x 500mm false rectangles and the joints between slab and walls shall be rounded off in the form of vata. The whole terrace shall be flooded with water for a period of 2 weeks for curing and for final test The proportion of the chemicals to be used in respect of ordinary portland cement shall be 1% by weight i.e. 1 kg of chemicals shall be mixed with 100 kg ordinary cement and the quantity of cement used shall be a minimum of 5 bags per 9.29 sq.m. of the area treated. 5.3 Sodium Silicate Treatment This treatment consists of application of 3 coats of a solution of 1 part of silicate of SICA to 3 parts of water, each coat being copiously applied with a soft broom at intervals of 24 hours. Alternatively, if any other lining is specified, the same shall be carried out as per drawings and manufacturer s instruction.

10 ISSUED: CIVIL DESIGN DEPARTMENT PAGE 10 OF Brick Bat Coba Treatment Wherever specified, this shall consist of 100 parts of broken bricks of the sizes of approximate 20mm to 40mm and 45 parts of lime mortar (1:2) machine mixed or 1:6 cement mortar. The above ingredients shall be well mixed and only sufficient water added to make the mixture plastic. The mixture shall be laid over the concrete surface and shall be well rammed with wooden batten to the required slope. The surface shall be trowelled smooth so as to bring the mortar to the surface. The surface shall be kept moist for 7 days. 5.5 Box Type Method This is an external waterproofing treatment and shall be applied to the basement and underground water tank structure. The impregnation structure shall be treated with the above treatment during the initial state of construction to ensure 100% water tightness. The waterproofing layers shall be laid over the evenly laid bedding course of concrete after cleaning the surface. Rough stone slabs are then laid side by side, leaving a gap of about 15mm to 20mm between them. These joints thus left are racked open and cement slurry admixed with chemicals is, grouted in these joints. A protective layer of about 25mm thickness of cement mortar 1:5 (1 cement: 5 coarse sand) with stone chips embedded at random, is put over stone layer. The total thickness of the water proofing layer shall be minimum 75mm. The treatment is extended 150mm beyond the external face of the R.C.C. raft slab and where sidewalls are laid. The treatment shall be carried over to the sidewalls. The impregnation treatment shall be continued of the external sides of the walls and up to 300 mm above ground level. Rough stone slabs of thickness 12mm to 16mm shall be fixed with the help of cement paste, applied on the internal face of the vertical joints of the stones leaving a gap of about 18mm between the external face of R.C.C. wall and internal face of the rough stones. The stones are fixed side by side within 25mm deep groove made in the bottom R.C.C. slab and the stones fixed in to ensure the water tightness at the junction of the walls and raft, if the raft is projecting beyond the external face of walls. Maximum of two to three horizontal layers of rough stones is laid at a time. A coat of very rough cement plaster 1:5 (1 cement: 5 coarse sand) is applied to the external face of rough stones. After the layer is set, the gap between the walls and the stone layer is filled with a grout mix made up of cement slurry and cyclic based chemicals. 5.6 Injection and Grouting Method In general the waterproofing shall be carried out as per specification of the specialist but duly approved by the Engineer-In-Charge.

11 ISSUED: CIVIL DESIGN DEPARTMENT PAGE 11 OF 13 The roof surface shall be cleaned thoroughly, watered and shall be kept wet at least 12 hours prior to carrying out of waterproofing. If any leakage is observed, the source of leakage shall be located and it shall be treated either by injection grouting or by closing of the crack with application of cement mortar 1:2 after cutting a V-shape groove. The treatment shall be continued till the leakage is stopped. The junction of the bottom raft with the vertical wall, is to be opened and filled with metal aggregate of nominal size along with injection. In the wall area, all construction joints are opened where found necessary as per site conditions. The injections are filled with cement slurry (grouting). A layer of I.P.S. of about 50mm thick on the floor shall be provided and the vertical wall is covered with sealproof waterproof layer of about 25mm thick. Where specified, this work shall be carried out by the LSTK CONTRACTOR who has specialized in carrying out this work. The LSTK CONTRACTOR shall give a 10 years guarantee on a stamped paper for good performance of his work and shall undertake to rectify the work at his own cost if any defects are observed during the guarantee period. 5.7 Applications Surface method is used to treat concrete masonry or any other surface of roof/ terrace slab/ floor of bldgs Box type method is used to treat under ground structures viz. basement/ water tank/ pits etc Injection and Grouting Method is used to treat existing structure for water proofing, from inside where access to external surface is not available for under ground water tanks, basement, pits etc. 5.8 Manufacturers All India Water Proofing Company - Specialist in cement based water proofing as described in 5.2, 5.3, 5.4, 5.5 and 5.6 above For Integral Water Proofing Compounds various manufacturers are available viz. FOSROC, SICA QUALCRETE, MC-BAUCHEME, STP Ltd., CHEMBOND, etc. 6.0 POLYURETHANE WATERPROOFING 6.1 Materials Materials shall consist of 2 pack clear/ pigmented Alphatic polyurethane using polyether polyols with Iso-cynorate for rendering flame resistant characteristic. Polyester or Castor Oil based Polyols shall not be used. The 2 pack system, consisting of resin and hardener (Xylene /Toluene) shall be mixed in proportions

12 ISSUED: CIVIL DESIGN DEPARTMENT PAGE 12 OF 13 by weight as per approved manufacturer s specification. The coating shall have high resistance to impact, abrasion and cracking. Tensile strength shall be 80 kg/cm² after 4 weeks at ambient temperature. It shall be perfectly smooth, dust free and shall retain glossy finish at least upto 3 years. It shall be resistant to acid, alkalis and have a very low water absorption rate of 0.5% maximum at ambient temperature after 7 days. The packs shall not be older than 9 months after the date of manufacture and packing. 6.2 Workmanship Preparation of surface The roof surface shall be thoroughly cleaned with a wire brush and all foreign matter etc shall be removed. Well defined cracks on the surface shall be cut to V section, cleaned and filled up flush with a paste of 2 component polyurethane based crack filling compound and white cement in a ratio of 1: Primer Coat Primer coat shall be mixed in the ratio as per manufacturer s specification. A single coat of this primer shall be applied by brush over the prepared bed as an adhesion coat. The primer shall be allowed to dry for minimum of 8 hours before the successive finishing coats of Polyurethane are applied Finishing coats The finishing coats shall consist of three successive pigmented seating coats each of 2 pack polyurethane, mixed in the ratio as per manufacturer s specifications. Application shall be with brush, to a smooth and even finish. The overall dry film thickness shall be 450 microns with a minimum covering capacity of 200 gms/m² per coat. Ambient temperature at the time of application shall not be less than 5 C and not more than 40 C. Each coat shall be allowed to dry for minimum 8 hours or as per manufacturer s specification before applying next coat. Care shall be taken for quick application after mixing the 2 pack primer in view of short pot life of the mix and shall be fully consumed within the stipulated period as per manufacturer s specification. (Maximum 60 minutes at 30 C). Polyurethane coating shall be continued up the parapets/ walls for a minimum of 150mm over the finished roof surface. It shall be continued into rain water pipes by at least 100mm. Treated surface should be allowed to cure for minimum 72 hours.

13 ISSUED: CIVIL DESIGN DEPARTMENT PAGE 13 OF Cement Screed The final coat of polyurethane, when tacky shall be sprinkled with 300 micron layer of clean sand. Plain cement concrete (1:2:4) of 25mm minimum thickness with 24 SWG chicken wire mesh shall be then laid to slope in panels not exceeding 6 M² area per panel. The joints between panels shall be raked out neatly to a minimum 6mm x 6mm V-groove and filled up with an approved quality elastomeric compound sealant. Drain outlet shall be provided for all spouts/rain water pipes by suitable rounding, filling and skoping of PCC as per drawing. At the junction of the roof and parapet or any other vertical surface, a fillet of 75mm radius shall be formed in cement mortar 1 cement: 4 coarse sand. 6.3 Guarantee The agency for waterproofing shall furnish a guarantee, which shall be agreed upon in the Contract to ensure the successful performance of the Contract. The guarantee shall be for a period of 10 years. Any work required to be carried out as a result of any defects in workmanship during the period of the guarantee shall be carried out by LSTK CONTRACTOR at his cost.