COMPOSI E REINFORCEMEN S T

Transcription

1 COMPOSI REINFORCEMEN T E S

2 CONTENT Composite reinforcements GENERAL TECHNICAL CONDITIONS OF COMPOSITE REINFORCEMENTS PREFA REBAR PREFACARB...7 Reinforcement system PREFACARB L Strengthening system PREFACARB R Notes Contacts cover

3 COMPOSITE REINFORCEMENTS PREFA Rebar Composite reinforcement (FRP) intended for the concrete structures is a heterogeneous material consisting of two basic components a load-bearing component in the form of unidirectionally oriented fibers and a binder composed of a polymer matrix. The resulting composite properties are determined primarily by the type and by the ratio between the two components. MAIN FEATURES AND BENEFITS: Chemical resistance Composite reinforcements due to its composition resist to an aggressive environment in the chemical plants and sewage treatment plants. They are indifferent to chlorides and very slightly affected by the ph. Composite reinforcements have in comparison to steel reinforcements significantly higher resistance to the aggressive chemicals (acids, acid chlorides, etc.). They are corrosion resistant, lightweight, nonconductive and indifferent to magnetic fields (do not block the radio signal) or to the stray currents, etc. FRP reinforcements can have (with the respect to the chosen composition) significantly higher tensile strength than the conventional steel reinforcement inserts. With regard to the above, it is not necessary to comply with the provisions of the standards to determine the thickness of the covering layer with regard to the durability of the structure. Corrosion resistance Composite reinforcements are corrosion-resistant. Therefore it is not necessary to cover the reinforcement. Thus, can be achieved material savings by designing a more subtle element. Thermal non-conductivity Composite materials are thermally nonconductive. So there is no formation of thermal bridges. Electrical non-conductivity Composite materials are electrically nonconductive. This prevents from corrosion caused by stray currents. Electromagnetic transparency The use of composite material for building structures that do not restrict the transfer of electromagnetic signals cell phones, television, radio, internet. It is suitable for applications near the high voltage cables and nearby the voltage transformers. 1

4 Among the disadvantages of the use of FRP reinforcement belongs mainly the decrease of the mechanical characteristics, which are negatively affected by the concrete ph during the life of the structure (this applies mainly to the GFRP reinforcement). The disadvantage of FRP reinforcement can also be of the lower modulus of elasticity which reduces the resulting rigidity of the structure. FRP reinforcements, when compared with the steel, have the lower resistance to the high temperatures. Promising application area for the use of the composite FRP reinforcement are mainly the concrete elements exposed to the aggressive environment, which normally undergoes rapid depassivation of the cover layer and subsequent degradation (corrosion) of the load-bearing steel reinforcement. These are primary structures exposed to chlorides, sulphates; construction in the occurrence area of the stray currents, digester tank, etc. The ideal application areas are primarily concrete elements occurring in the chemical industry, the energy sector (energy channels and pipeline canals, collectors), in the transport (the salt effects caused by the winter maintenance) and the foundation construction. For these structural elements are favorably used positive characteristics of FRP reinforcements, which makes its higher initial investment quickly offset by significantly cheaper maintenance of the structure and it s longer lasting. FRP reinforcement (from the left) - GFRP, C-GFRP, CFRP σ f f,l,m f f,l,k LT f f,l,k LT f f,l,d Stress short-term strength mean short-term strength characteristic long-term strength characteristic long-term strength design value In the production are normally used glass (E-CR), or a carbon (HS) fibers GFRP reinforcement, respectively CFRP reinforcement. Individual types of load-bearing fibers are, in order to reduce costs and to achieve the desired parameters, possible to combine hybrid C-GFRP reinforcement. Fibre content normally varies between 75 and 80 % (by weight). All types of FRP reinforcements are manufactured by pultrusion with a winding and to increase the cohesion with the surrounding concrete coated surface treated with silica sand. LT LT ε f ε,l,d f,l,k ε f,l,k ε f,l,m Strain Idealized design diagram of the FRP reinforcement, taking into account the time-dependent (long-term) strength ε Reinforcement anchoring is realized by cohesion or with the help of the specially designed fasteners, which surface treated with silica sand shorten the anchorage length. The composite reinforcements can be bent on the customer s request, however only in the uncured 2

5 The basic physico-mechanical parameters of the manufactured FRP reinforcements are listed in the following table. All the data shown are a short-term, ie. not reflecting the long-term behavior, determined at a temperature of approx. 20 C. The long-term properties need be considered depending on the environment to which the reinforcement is exposed to, and the load rate to be exposed. Detailed technical specifications are subject to the technical data sheet of the product. PREFA Rebar Reinforcement type GFRP C-GFRP CFRP Load-bearing fibers Matrix Surface finish E-CR glass E-CR glass HS carbon epoxy resin winding with sand HS carbon Available diameter mm 6 to to 18 6 to 18 Tensile strength (median) f f,m MPa > 1 100* > 1 100* >1 850* Tensile strength (characteristic) ** f f,k MPa > 1 050* > 1 050* >1 700* Modulus of elasticity (median) E f,m GPa > 50* > 75* > 94* Shear strength / cutting (median) f s,m MPa Shear strength / cutting (char.) ** f s,k MPa Thermal expansion longitudinal direction α L K ,0 Thermal expansion transverse direction α r K Density ρ kg m Characteristic value (EC) Environmental reduction factor * depending on the diameter of the reinforcement ** in accordance with the EN 1990, considered the 5 % quantile condition in the factory. Shaping is not possible at the construction site. Basic characteristics of the FRP reinforcements resulting from their physical essence is the orthotropic behavior, ie. material properties of the FRP reinforcements achieve different values in the direction of the load-bearing fibers orientation and in the perpendicular direction. The load-bearing fibers are elastic, fragile and brittle. For this reason, the composite reinforcements when exposed in to the tensile stress with the direction of the fibers linearly elastic and the brittle fracture at the reach of the ultimate stress and the work diagram always have a linear course until the failure see Figure. When designing the structures reinforced with the FRP reinforcements it is necessary to proceed in accordance with applicable regulations and design documentation. FRP reinforcement is primarily intended for the tension areas of structural elements. Not to be used as a load-bearer of the compressed areas. The mechanical characteristics of the FRP reinforcement in compression in the direction of the fibers are lower than when a tensile stress, and are strongly dependent on the time creep. Nominal diameter [mm] Diameter including adhesive layer [mm] Cross-section [mm 2 ] Weight [g/m]

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7 GENERAL TECHNICAL CONDITIONS OF COMPOSITE REINFORCEMENTS PREFA REBAR DESCRIPTION AND TYPES OF COMPOSITE REINFORCEMENTS Composite reinforcements are produced in several basic designs, which are determined by its corresponding application. Glass or carbon fibers have the supporting function, 100 % of these fibers is deposited in the longitudinal direction. Fibers can be made of glass (type AR or E), carbon or another (e.g. basalt). The fiber content is in the range of % (regarding the weight). The binder is a vinyl ester, polyester or epoxy resin. On the surface of the reinforcement, above the spiral shape, securing the reinforcement shape is the silica sand poured into the resin. Composite reinforcements are possible to bend only in the uncured condition. It is not possible to shape it on the site. Other characteristics Nominal diameter The diameter of reinforcement. Available nominal diameters in the range of 6 18 mm. Overall diameter... The diameter including a layer of silica sand on the reinforcement surface. Usually about 2 mm larger than the nominal diameter. The radius of bend... Rods bending radius of shaped reinforcements. Unless stated otherwise, is 50 ±5 mm. Diameter roundness... ± 10% Cohesion with concrete MPa Density g/cm 3 PRODUCTION DOCUMENTATION Composite reinforcements are manufactured according to the production specifications, provided by the purchaser, or the documentation provided by the seller in accordance with the requirements of the buyer. Production documentation, supplied by the purchaser for the direct reinforcements must contain: Length of reinforcement Reinforcement nominal diameter Type of reinforcement Production documentation, supplied by the purchaser for the curved shapes must contain: Drawing of bent-shaped reinforcement Reinforcement nominal diameter Type of reinforcement 5

8 PRODUCT QUALITY Quality control of products is regularly maintained in accordance with the guidelines for quality management system according to ISO 9001 and ISO Production of composite reinforcements is governed by standards EN to -3. Proof of quality is written on the delivery notes of customer s invoices. In accordance with the provisions of Law no. 22/1997 Coll. of technical requirements for products, after the delivery of products, the buyer gets the declaration of conformity. DIMENSIONAL TOLERANCES OF BUILDING COMPONENTS They are listed in the production documentation and in the PREFA KOMPOZITY, a.s. corporate standards: Element name PREFA Rebar Straight bars Length [mm] Nominal diameter [mm] Total diameter [mm] Width [mm] Height [mm] ±5 ±0.3 ± SURFACE OF REINFORCEMENTS The common composite reinforcements surface is covered with a layer of silica sand poured into the resin. It does not have cracks or any fibers not soaked in the resin. Permissible are areas without silica sand or resin drops, the total surface of these places should not exceed 10 % of the total reinforcement surface. Where the composite reinforcement have bends always occurs flattening of the cross-section, also on the inner surface the area is smooth (silica sand is pressed into the surface). The above-mentioned deviations can not be considered for a claim. Standard reinforcements are produced in a natural coloration or in a light gray color. At the customer s request can the reinforcements be produced also in other colors. 6

9 GENERAL TECHNICAL CONDITIONS OF COMPOSITE REINFORCEMENTS PREFACARB MATERIAL CHARACTERISTICS OF PREFA CARB Strengthening system can be supplied in options: System lamella+glue (PREFACARB L) System mat+glue (PREFACARB R) The PREFACARB L manufacture standard is made from high tensile strength carbon fiber reinforcement and an epoxy resin. At the customer s request can also be supplied reinforcements of polyester or vinyl ester resin and glass fiber reinforcement. As the adhesive is used 2-component epoxy adhesive PREFEPOX L. For both systems can be used carbon fibers with a higher modulus of elasticity Dimension [mm] Cross-section [mm 2 ] Type PREFACARB L Weight [g/bm] Type PREFACARB R The PREFACARB R manufacture standard is made of high tensile strength carbon fiber reinforcement. At the customer s request can also be supplied glass or any other fiber reinforcements. As the adhesive is used 2-component epoxy adhesive PREFEPOX R. General properties of composite reinforcement Nomenclature of PREFACARB type L type R Properties Units Fiber type HS carbon HS carbon Resin epoxy --- Surface finish smooth or a tear-off mat --- Tensile strength *) [MPa] Modulus of Elasticity E *) [GPa] Fiber content [%] 70 % 100 % Density [g/cm 3 ] Thermal expansion - longitudinal direction Thermal expansion - transverse direction *) Listed are the average values of measured quantities [K -1 ] [K -1 ]

10 Reinforcement system PREFACARB L Composite system for additional strengthening of structures A high-strength system for additional strengthening of concrete, wood, steel, and other composite structures. The system can be used to further increase the load bearing capacity of existing structures, increasing the load bearing capacity of damaged structural elements. The system consists of: Composite lamellas usually composed of a carbon reinforcement and epoxy resins Adhesive materials based on epoxy resins, solvent-free APPLICATION: It is being used for additional reinforcement of structures at: The load increases - payload increase of ceiling structures - installation of heavy equipment Damage to the load-bearing elements - accident vehicle impacts, fires - the aging of construction materials - corrosion of the steel reinforcement - the formation of cracks Improving utility properties - reduce of deflections - increase the passage height Change of the static system - reducing the number of supports - new holes in the horizontal and vertical structures BENEFITS: Lightweight reinforcement element easy to handle, does not require supports during curing adhesives Can be applied on vertical walls and on the bottom side of the ceiling structures High tensile strength of reinforcement element The crossing of lamellas is possible Does not corrode Maintenance free application Simple assembly TECHNICAL DATA: LAMELLA Color black Shelf life Unlimited. Do not expose to direct sunlight Packaging Coiled in spools. Can be supplied cut to pre-agreed length. Weight kg/bm lamella Density 1.6 g/cm 3 Modulus of elasticity in tension > MPa Tensile strength >3 000 MPa Temperature resistance to 120 C Carbon fiber content >70 % Coefficient of expansion K -1 PREFEPOX L Color component A white component B black Shelf lifeat least 3 months in original containers at temperatures of 5 25 C. In a case of deposits, it is necessary to mix this sediment. Packaging In the pre-dosed packaging. Workability time30 minutes (at 20 C and in a small amount) Mixing ratio by the weight A:B 1:1 with a tolerance of 10 % by the volume A:B 4:3 with a variation of 10 % Consumption from 0.5 kg/m lamella depending on the roughness and inequalities of the surface Density component A 1.50 g/m 3 component B 2.00 g/cm 3 mixture 1.75 g/cm 3 Shear strength >8 MPa 8

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12 Strengthening system PREFACARB R COMPOSITE SYSTEM FOR ADDITIONAL STRENGTHENING OF STRUCTURES High tensile strength system for additional strengthening of concrete, wood, steel and other composite structures. The system can be used to further increase the load capacity of existing structures, increase the load capacity of damaged High-strength system for additional strengthening of concrete, wood, steel and other composite structures. The system can be used for an additional increase in the load capacity of existing structures, increase the load capacity of damaged loadbearing elements. System consists of: Mats made of unidirectionally imposed carbon fiber Epoxy laminating resins, solvent-free APPLICATION: It is being used for an additional reinforcement of structures at: The load increases - increase the payload of ceiling structures - incorporation of heavy equipment The damage to the load-bearing elements - accident vehicle impacts, fires - aging of construction materials - corrosion of the steel reinforcement of concrete - formation of cracks Improving utility properties - reduce of deflections - increase the increase the passage height The change of the static system - reducing the number of supports - new holes in the horizontal and vertical structures BENEFITS: Lightweight reinforcement element easy to handle, does not require supports during curing adhesives Can be applied on vertical walls and on the bottom side of the ceiling structures High tensile strength of reinforcement element The crossing of lamellas is possible Does not corrode Maintenance free application Simple assembly 10

13 TECHNICAL DATA: MAT Color Shelf life black Unlimited. Packaging Coiled in spools. The width of the belt is 0.3 or 0.6 m. Weight from 200 g/m 2 to 600 g/m 2 Density 1.8 g/cm 3 Modulus of elasticity in tension from MPa Tensile strength MPa Carbon fiber content >98 % Coefficient of expansion K -1 PREFEPOX R Color component A white component B black Shelf lifeat least 3 months in original containers at temperatures of 5 25 C. In the case of deposits, it is necessary to mix this sediment. Packaging In the pre-dosed packaging Mixing ratioby weight A:B 1:1 with a tolerance of 10 % By volume A:B 4:3 with a tolerance of 10 % Workability time30 minutes (at 20 C and in a small amount) Consumption 2.5 to 3.0 kg/m 2 depending on the roughness and inequalities of the surface Density component A 1.10 g/cm 3 component B 1.80 g/cm 3 mixture 1.45 g/cm 3 Shear strength >8 MPa 11

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16 PREFA KOMPOZITY, a.s. n Kulkova 10/4231 n Brno