DETAILED MATERIAL SPECIFICATIONS
Specification For Concrete Penetrating Corrosion Inhibitor
Surface Applied
Description:
Concrete penetrating corrosion inhibitor upon addition / application into the concrete matrix inhibits the corrosion process, C.P.C.I. need not be in direct contact with the steel. They migrate over a considerable distance by virtue of its bipolar inhibition mechanism property (B.I.M) to provide protection to the steel. Non-migrating and inorganic corrosion inhibitors are specifically excluded from this specification.
The C.P.C.I. shall be free from nitrite, chromates phosphates & other toxic elements.
Application : Surface application : Minimum 4 sq. mt / lt.
Grouting Application : 100 ml per nipple.
Nipples to be fixed at 300 mm c/c
Base :Water based organic corrosion.
Appearance : Clear brown liquid
Toxicity : Non toxic
Specific Gravity : 1.02 to 1.07
Flash Point :NA (Water Based)
pH :Minimum 9
Acceptance Criteria:
Inhibitor shall have minimum 7 years successful usage history in Indian conditions and shall effect the corrosion rate reduction.
Tropical Compatibility:
Material shall have evaluated test reports indicating significant reduction in corrosion rate after minimum of 90 thermal cycles at 60oC followed by 8 weeks of accelerated corrosion.
The inhibitor shall be non-toxic & safe to plant and human life.
Specification for Alkaline rust converting primer.
The alkaline rust converting primer shall be organic polymer based & shall be free from mineral, and phosphoric acid & chromic acids.
Base:Organic (Water based acid free)
pH:7.5 to 8.5
Specific Gravity:1.04 to 1.10
Appearance :Dark Brown
%Solids:Minimum 10 %
Flash Point: N.A.
Properties: 1.Shall pass minimum 400 alternate immersion cycles of 2
minutes cycles in 3.5% NaCl solution at room temperature.
2. Shall pass minimum 72 hours of Salt Spray test
as per ASTM – B- 117.
Product: Feovert or equivalent
Specification for Anti corrosive coating ~ IPNet RB
Anti – corrosive coating to the exposed reinforcement.
Applying two coats of IPNet-RB (Interpenetrating polymer with epoxy / phenolic base) manufactured under technical license from Central Building Research Institute (C.B.R.I.), Roorkee to exposed corroded bars and to new reinforcement.
Specifications :
After application of rust converter (FeoVert) and air curing for minimum 6 hours apply two coats of the formulation given below by brush with time interval of min. 9-10 hours between the coats.
IPNet-RB Part-A (resin component) & IPNet-RB Part-B (hardener component) in equal proportion by volume.
Methodology :
The mixing shall be done in a clean plastic container. The component shall be mixed thoroughly for 3-4 min. and allowed to remain in the container for another 2-3 min.
The mix shall be consumed within 30 min. and only such quantity as can be used within 30 min. shall be mixed at a time.
The application shall be by brush. The 2nd coat shall be applied after 7 hours. The 2nd coat can be delayed upto a max. of 7 days.
The 2nd coat when tacky, dry sand with silt content not more than 3% shall be sprinkled so as to provide a rough finish. An air curing period of min. 10 hours shall be ensured after the top coat before any subsequent treatment.
Al l instructions from the manufacturers regarding the use of the product, storage, health precaution of workers, cleaning of tools etc. shall be followed.
After 2 hrs. the surface to be slight touched with dry brush to remove loose sand grains.
Measurement mode :
SMt.
Acceptable Product :
IPNet-RB manufactured by Krishna Conchem Products Pvt. Ltd.
Note :
The mixing of IPNet-RB part-A & IPNet-RB part-B shall be done with respect to volume and not as per weight.
Ensure proper mixing for minimum 3-4 minutes.
Don’t apply IPNet-RB on wet surface.
IPNet-RB to be used in clean, dry plastic mug.
The both coats of IPNet-RB should be allow to dry in air (no water curing).
Allow both the coats to dry in air with 7 hours as intercoat interval and allow the 2nd coat to dry for 10 hours.
Further bond coat and mortar to be applied only after 10 hours of application of IPNet-RB.
Specifications For Long Pot Life Epoxy Bonding Agent
The bonding agent shall be based on epoxy bond system.
Material Specifications
Base / : / EpoxyViscosity / : / 1000 cps at 25º C
Pot Life / : / 2 hour at 25º C
Type / : / ASTM-C-881-91
Bond Strength at 2days 6.9 Mpa.
Bond Strength at 14 days 10.3 Mpa.
Product : EPIBOND-21-LP
Specifications For Low Viscosity Epoxy Grout
The KP/HP-250 -SLV grouting resin hardener system shall be thermosett system on 100 % solids basis. The system shall have extended pot life of minimum 1 hour at 25º C.
Surface Preparation : The grouting to be done – area shall be freed from grease, oily residues. Drill holes of 14 mm dia at 300mm centre to centre in a grid pattern and clean the holes with clean compressed air prior to fixing nylon nipples of 12 mm dia. Fix the nipples with epoxy / polymer putty and allow to set.
Grouting pressure: 3 to 5 kg / cm2
Grouting gun : Rohibb handheld grouting machine or equivalent.
Material Specifications
Base / : / Epoxide resin with curing agent.Viscosity / : / Maximum 200 cps at 25º C
Compressive Strength of Resin + Hardener / : / 350 kg / cm2 min
Flexural Strength / : / 110 - 130 kg /cm2
Bond Strength / : / 80 – 100 kg / cm2
Pot Life / : / 45 min at 25º C for 1 kg mix
Product: EPCO-KP/HP-250-SLV or equivalent.
Specifications For Low Viscosity High Molecular Weight Thermosette Grout
The grout shall be low viscosity high molecular weight thermosetting polymer concrete impregnating & strengthening the concrete matrix.
Material Specifications
Material : Low viscosity high molecular weight thermo sett polymer grout. Viscosity : Less than 5 centipoises per second (ASTM-D-2196)
Specific Gravity : Less than 1.0 (ASTM-D-1963) Temp. range for working : 5°C to 55°C
Mechanical strength properties of the material (after 7 days)
1) Compressive strength (ASTM-D-695-96) – 50-70 N/mm2
2) Tensile strength (ASTM-D-638-95) – 16-20 N/mm2
3) Flexure (ASTM-D-790-96) – 35-45 N/mm2
Pot Life / : / 30 min for 1 lt mix at 25º CGrouting pressure / : / 3 to 5 kg / cm2
Grouting gun / : / Rohibb handheld model 701 or equivalent.
Acceptable Product: Monopol or equivalent
Specifications for Non-re-emulsifiable epoxy latex system
Base / : / Non-re-emulsifiable epoxy latex system cement compatible for polymer modified mortar, concrete & bonding applicationMix Viscosity / : / >2000 cps at 25º C
Bond Strength
(With cement matrix) / : / min 8.61 Mpa as per ASTM-C-1059-91
Compressive Strength at 28 days
(1:3 Cement mortar with river sand & 5 to 10% Epoxt-Latex by wt. of cement & w/c ratio 0.30) / : / 300-350 kgs/cm2
Acceptable Product: EL-Monobond- or equivalent
MONOBOND®
Polymer Latex Additive for Polymer Modified Concrete/Mortar/Grouts
Monobond® is a polymer latex additive for modifying cement concrete / mortar / plaster / grouts. The addition of Monobond® improves mechanical properties especially flexure and tension. Due to low permeability of polymer-modified systems, remarkable improvement in prevention of carbonation, chloride ion penetration is observed. Also chemical resistance improves significantly.
The addition of Monobond® imparts resilience to the cement matrix. Thereby improving impact resistance. Also the modified cement matrix cures in air, eliminating the necessity of wet curing.
It is necessary to mix Monobond® in water first prior to addition in cement mortar/concrete.
TYPICAL APPLICATIONS :
- Excellent Repair Mortar, for strengthening dilapidated RCC structures.
- Due to the excellent chemical resistance properties of PMC it can be used in Chemical plants as Industrial Floor Topping compound.
- Excellent lining material on concrete surface to protect it against carbonation, chloride ion penetration, etc.
- As bond coat.
- As an additive to cement grout.
APPLICATION PROCEDURE:
Mix Monobond® in water first prior to addition in cement mortar/concrete. Dosage 5% to 10% by weight of cement.
Technical DATA:
Base : Polymer Latex
Appearance : Milky White
pH : > 8.0
Packing : 1 kg., 20 kgs.
Typical Mix Design For
Polymer Modified Mortar
Cement :100 P.B.W.
Sand :300 P.B.W.
Monobond® :5 to 10 P.B.W.
Water :30 to 35 P.B.W.
Polymer Modified Concrete
Cement :100 P.B.W.
Sand : 200 P.B.W.
Aggregate
M1 (20 mm down): 300 P.B.W.
Monobond® :5 to10 P.B.W.
Water : 35 to 40 P.B.W.
Specifications For Non Shrink Epoxy Putty
Base / : / EpoxyCompressive Strength / : / 200 to 250 kg / cm2
Shrinkage / Negligible
Acceptable Product: EPCO-1010 or equivalent
(6) Specification for unidirectional e-glass fiber composite material
Technical Data:
Young's Modulusof Elasticity. / : / 75,900 N/mm2
Specific Gravity
of Fiber / : / 2.56
Tensile strength in
Uni-Direction / : / 2060 MPa
Density of Wrap / : / 900 gms / m2
600 gms /- m2 BD
Effective Fiber
Sheet Thickness / : / 0.43 mm for 900 gsm
0.27 mm for 600 gsm BD
Elongation at / : / 0.04
At break
Composite Laminate Properties
Tensile Strength / : / 875 N/mm2Tensile modulus / : / 60,000 N/mm2
Strain / : / 0.0146
Precured Glass Plate-Goldbond ® - Superplate-G
Grade / : P-2550Base / : E-Glass fiber reinforced in epoxy matrix
Dimensions / : 2.5 mm (Thickness) x 50 mm (width)
Volume fraction of fiber / : 65% minimum
Modulus of elasticity (E) / : 41 GPa
Tensile Strength / : 690 MPa
Elongation at break / : 2%
Shelf life / : Unlimited at room temperature
The above properties are for longitudinal direction of fibers.
Goldbond ® - Superplate-C
Grade / : C-1250Base / : Carbon fiber reinforced in epoxy matrix
Dimensions / : 1.2/ 1.4 mm (Thickness) x 50 mm (width)
Volume fraction of fiber / : > 70%
Modulus of elasticity (E) / : 165 GPa
Tensile Strength / : 2800 MPa
Elongation at break / : 1.7%
Shelf life / : Unlimited at room temperature
The above properties are for longitudinal direction of fibers.
UNIDIRECTIONAL CARBON FIBER PLATE
Grade / : CF-1450Base / : Carbon fiber reinforced in epoxy matrix
Dimensions / : 1.4 mm (Thickness) x 50 mm (width)
Modulus of elasticity (E) / : 165 GPa
Tensile Strength / : 2800 MPa
Elongation at break / : 1.7%
Shelf life / : Unlimited at room temperature
The above properties are for longitudinal direction of fibers.
Repair Methodology
A. Repair Methodology for Excessively damaged RCC Section
- CHIPPING:
Chip off loose and carbonated concrete from surface of existing structural elements with help of chisel and hammer till sound concrete is encountered. Remove laitance, oil etc. present on concrete surface by grinding/ sand blasting. De-scale the surface of exposed reinforcement with help of brush to remove the rust scales. Carbonated concrete if left in structure shall initiate deterioration process.
- CORROSION TREATMENT:
a) Application of Concrete penetrating corrosion inhibitor on concrete surface
Carry out application of ‘Bi-polar migratory corrosion inhibitor on concrete surface by brush in two coats. This inhibitor has migratory kind of property which permits the material to migrate to a virtual extent of 100 mm, through pores of concrete, inhibiting the corrosion and de-passivating the Electro-chemical reaction. It has property to attack anode as well as cathode, which is purely alkaline in nature (pH-9.5), so it has no carcinogen activity with concrete. And material shall confirm to ASTM………….
Grout the corrosion inhibitor in case of excessively damaged RC sections by drilling 50 to 75 mm deep holes at the spacing of 350mm c/c in concrete body.
b) Treatment to corrosion damaged existing steel reinforcement.
i) Application of rust converting alkaline primer:
Thoroughly clean the corroded reinforcement/ steel rebar by wire brush or rotary grinder. Remove all the corrosion scales present on the bare and reach up to sound steel. Apply of rust converting alkaline primer on corrosion affected steel bars after removing all the scales. It is alkaline in nature and convert both hematite & magnetite compounds in to stable compounds. The material shall pass salt spray test as per ASTM-B-117.
ii) Application of two coats of IPNet- RB anticorrosive epoxy coating on steel rebars:
Application of primer shall be followed with application of two coats of IPNet- RB (confirming to CBRI requirement) anticorrosive epoxy coating for bar protection against future corrosion. Coating is for old a well as newly provided steel. This system (Interpenetrating polymer network system for rebars: IPNet-RB) once applied on steel shall provide extended protection against future carbonation and chloride attack.
- MAKING UP OF LOST STEEL AREA DUE TO CORROSION BY ADDITIONAL STEEL
Makeup lost steel area due to corrosion by providing additional steel reinforcement. The steel shall confirm to IS……..Anchor the steel rebar in sound concrete body up to desired depth by structural GRADE adhesive. Fixing of rebars is to be with pre left binding wires with existing steel at regular grid after aligning concrete profile with new mortar up to existing steel face.
- MAKING UP LOST STRENGTH OF CORE CONCRETE BY LOW VISCOSITY MONOMER
Make up of lost strength of core concrete shall be with grouting of low viscosity ( 2-5cps- as per ASTM-D-2196) monomer. This is a low viscous high molecular weight thermosetting polymer. Due to its low viscosity it effectively fills up all micro-cracks and voids up to full depth of concrete. Grouting with this system shall provide gain in core strength by 15 to 20 %. Beside enhancing existing binding matrix this shall also enhance in ductility property of elements.
Description of Grout:
- Drilling of holes 12mm dia and about 1/3 rd of element deep into concrete along the cracks or in honey combed and deteriorated areas, fix the perforated nozzles and seal the sides with Epoxy sealant.
- Epoxy sealant: This is a non-shrink sealant. It is built in resilience to absorb impact and movements in joints.
- Inject very low viscous injection resin into pre- drilled nozzles at a pressure of 4kg/cm2 using compressed air and injecting gun. Seal the nozzles with epoxy after injection is completed.
- Making up lost –section with polymer modified mortar.
Makeup mortar is based on type of structural element and its location. Here following type of modified mortars are recommended.
Modified mortar:
For replacing the carbonated part of concrete and repairing the damaged surface of concrete usage of following formulated mortar is recommended.
Mix:
- Cement: 50KG
- Sand: 150KG
- Polymer Latex: 2.5 TO 5KG
- Water: 15-20 Ltrs.
- GROUTING OF STRUCTURAL CRACKS BY LOW VISCOSITY EPOXY GROUT
Grout the wide structural cracks in the concrete by grouting of low viscosity grout (200 cpc as per ASTM-D-2196). Cut a V-grove along the crack of proportionate size. Drill the holes along the crack at desired spacing. Seal the remaining portion by non-shrink epoxy putty to avoid any leakages of grout material. Grout the low viscosity material trough epoxy injection gun under pressure of 3t0 4 Kg/cm2. Cuh and seal the nozzles after 24 hrs of application of grouting.
7. Strengthening with non metallic Fibers Reinforced Composite-in select areas
- Application of pre engineered glass or carbon laminates:
Wherever loss of flexural reinforcement is more and as welding of additional steel is not feasible in some area because of crude oil pipe lines, it is recommended to use pre engineered glass of carbon laminates as follows
- Surface preparation:
Grind/ Sandblast repaired concrete substrate for cleaning rounding sharp edges to min 20-25 mm radius
- Profiling:
Apply compatible primer on prepared substrate, Fill holes and uneven surface with thixotropic putty.
- Application of plate
Mark the application area on structural element, cut the laminate to require size, applying compatible structural adhesive on plate in parabolic manner by using adhesive application machine, paste the laminate in desire area and orientation by using tamping roller to avoid any air voids
Fig 1: Strengthening of beam with GFRP/ CFRP Laminates
b) Procedure for wrapping with glass / carbon wraps
Wherever loss of shear and flexural reinforcement is more and as welding of additional steel is not feasible in some area because of crude oil pipe lines, it is recommended to use pre various fiber wraps of glass and carbon in damaged areas.
- Surface preparation:
Grind/ Sandblast repaired concrete substrate for cleaning rounding sharp edges to min 20-25 mm radius
- Profiling:
Apply compatible primer on prepared substrate, Fill holes and uneven surface with thixotropic putty.
- Wrapping:
Apply first coat of fiber compatible saturant, cut the fabric to size, wrap the fiber sheet to structural element at desired orientation using tamping roller to avoid any air voids.
- Finishing:
Applying second coat of saturant after min. 12 hrs, rectify air voids if any.
Providing U-Wrap For Shear - Type A
DESIGNE LAYUPS
Sketch 1: Schematic wrapping details for columns
Sketch 2: Beam column joints
Methodology for Grouting Epoxy Grout
Drilling and fixing metal nozzles in RC members, including,
Drilling Holes: Drilling 14 mm dia., 40 mm deep holes in structural members at the intervals of 600 mm in staggered manner or as directed by the consultants in RC structural element.
Cleaning of holes: Clean the holes by air blower prior to fixing nozzles.
Fixing of Nozzles: Insert 12 mm dia. metal nozzles in cleaned holes. External end of nozzles to be machine to receive outlet of grouting gun. Fix it inside the holes by applying Epoxy putty to ensure complete sealing. Cure the system for min. 12 hrs.
Mixing of materials: Mixing material components (part a & b) in required quantities as per manufacturer’s instruction by weigh batching.
Grouting: Fill the grouting gun with epoxy resin. Maintain desired pressure in the gun by air compressor; maintain the pressure at exit (3 to 5 Kg/ Cm2) by monitoring pressure gauge at exit or as per consultant’s instruction. Grout the material through prefixed nozzles in the structural elements still its refusal. Seal the nozzle with Epoxy putty after the refusal. Monitor leakages through other nozzles while grouting and seal them as per the requirement. Repeat the process for all the nozzles. Complete the operation within pot life of the material.
Cutting of Nozzles: Cut the nozzles by chisel after completion of grouting without damaging structural elements.
Cleaning of gun and accessories: Clean the gun and accessories (valves, pipes and other fixtures) with thinner after the operation to avoid jamming of the gun.