EP3873871A1 - Fibre pour armature de béton - Google Patents

Fibre pour armature de béton

Info

Publication number
EP3873871A1
EP3873871A1 EP19758782.7A EP19758782A EP3873871A1 EP 3873871 A1 EP3873871 A1 EP 3873871A1 EP 19758782 A EP19758782 A EP 19758782A EP 3873871 A1 EP3873871 A1 EP 3873871A1
Authority
EP
European Patent Office
Prior art keywords
fiber
concrete
cyclic olefin
polypropylene
olefin copolymer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP19758782.7A
Other languages
German (de)
English (en)
Inventor
Ives Swennen
Özlem ASLAN
Jeroen SMET
Lien VAN DER SCHUEREN
Luc Ruys
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Adfil NV
Original Assignee
Adfil NV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Adfil NV filed Critical Adfil NV
Publication of EP3873871A1 publication Critical patent/EP3873871A1/fr
Pending legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
    • C04B28/02—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing hydraulic cements other than calcium sulfates
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B20/00—Use of materials as fillers for mortars, concrete or artificial stone according to more than one of groups C04B14/00 - C04B18/00 and characterised by shape or grain distribution; Treatment of materials according to more than one of the groups C04B14/00 - C04B18/00 specially adapted to enhance their filling properties in mortars, concrete or artificial stone; Expanding or defibrillating materials
    • C04B20/0048—Fibrous materials
    • C04B20/0068—Composite fibres, e.g. fibres with a core and sheath of different material
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B40/00—Processes, in general, for influencing or modifying the properties of mortars, concrete or artificial stone compositions, e.g. their setting or hardening ability
    • C04B40/0028—Aspects relating to the mixing step of the mortar preparation
    • C04B40/0039—Premixtures of ingredients
    • C04B40/0046—Premixtures of ingredients characterised by their processing, e.g. sequence of mixing the ingredients when preparing the premixtures
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
    • D01F1/00—General methods for the manufacture of artificial filaments or the like
    • D01F1/02—Addition of substances to the spinning solution or to the melt
    • D01F1/10—Other agents for modifying properties
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
    • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
    • D01F6/02—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • D01F6/04—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds from polyolefins
    • D01F6/06—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds from polyolefins from polypropylene
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
    • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
    • D01F6/44—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from mixtures of polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds as major constituent with other polymers or low-molecular-weight compounds
    • D01F6/46—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from mixtures of polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds as major constituent with other polymers or low-molecular-weight compounds of polyolefins

Definitions

  • the invention pertains to synthetic fibers for concrete reinforcement.
  • Fiber reinforced concrete is not a new concept. Since biblical times fibers were used in cementing construction materials in the form of straw and horse hair. In more recent times the asbestos fiber was used extensively in structural components like wall panels, roofs and gates. In the early 1960’s the health risk of manufacturing and using asbestos fibers became apparent and alternative fibers were introduced as a replacement.
  • steel fiber was one of the first possible alternatives to steel bar reinforcing, with the first patent being applied for in 1874. It was however only in the early 1970’s that the use of these fibers on a large scale was noticed in the USA, Japan and in Europe.
  • Fibers are used in concrete to increase mechanical properties of concrete, to improve the volume stability of concrete, and to prevent cracking due to shrinkage of concrete. They also reduce the formation of drying and plastic shrinkage cracks to a minimum and improve concrete properties by increasing fire resistance, shock and impact resistance, and abrasion resistance of concrete.
  • Synthetic fibers Compared to steel fibers, synthetic fibers have the advantage of being non- corrosive, therefore being durable even in humid environments.
  • Synthetic fibers in particular polypropylene fibers, can be used as fibers for concrete reinforcement, in particular in concrete which is subjected to compressive loads, such as for example concrete floor slabs applied on a subfloor, or in shotcrete applications.
  • the synthetic fibers are generally applied to prevent, or at least reduce, the formation of cracks in the concrete and/or to increase the post- crack residual flexural tensile strength of the concrete, which enables to reduce post-crack deformation of the concrete.
  • Polypropylene (PP) fibers can be applied to the concrete in various forms, in particular as staple fibers, the staple fibers having small or large fiber diameters and/or various surface structures.
  • microfibers Polypropylene fibers with relatively small diameters are commonly known as “microfibers”.
  • Macrofibers of polypropylene (PP) have an equivalent fiber diameter of at least 300 pm.
  • Polypropylene macrofibers are in particular applied to improve the post-crack behaviour of concrete. They can replace steel mesh or steel fibres in non- structural applications like ground supported floor slabs and compression loaded applications. Increasing the tensile strength and/or the modulus of the synthetic fibers play an important role in increasing the post-crack residual flexural tensile strength of the fiber reinforced concrete.
  • the object of the invention is to provide synthetic fibers for concrete reinforcement having increased tensile strength and/or increased modulus.
  • the object of the invention is achieved by the fiber for concrete reinforcement according to claim 1.
  • a fiber for concrete reinforcement which comprises 85 wt.% to 98 wt.% of a polypropylene and 2 wt.% to 10 wt.% of a cyclic olefin copolymer has an increased tensile strength and/or an increased modulus as compared to fibers consisting of polypropylene, which enables to increase post-crack residual flexural tensile strength of the concrete.
  • the amount of fibers in the concrete can be reduced at constant post-crack residual flexural tensile strength which enables better handling, in particular the workability, of the concrete mixture.
  • the post-crack residual flexural tensile strength of concrete is determined, in accordance with test method EN 14651“Test method for metallic fibre concrete - Measuring the flexural tensile strength (limit of proportionality (LOP), residual)”, by a three-point bending test on a rectangular concrete beam having a length of 60 cm, a width of 15 cm and a height of 15 cm, the beam comprising a notch formed along the width and transversely to the length at the lower side of the beam. Load is applied on the upper side of the beam directly opposite to the notch.
  • the vertical displacement and the strength at specified opening width of the notch also known as crack mouth opening displacement or CMOD, are relevant characteristics of the fiber reinforced concrete (FRC).
  • FRC fiber reinforced concrete
  • the strength of concrete is determined in accordance with a round plate test according to ASTM C1550, the round concrete plate having a diameter of 80 cm and a thickness of 7.5 cm, in which the total energy absorption to 40 mm deflection is determined, or in accordance with a square plate test according to EN14488/5, the square concrete plate having a length and a width of 60 cm and a thickness of 10 cm, in which the total energy absorption to 30 mm deflection is determined.
  • a fiber for concrete reinforcement which comprises 85 wt.% to 98 wt.% of a polypropylene and 2 wt.% to 10 wt.% of a cyclic olefin copolymer can have improved creep resistance as compared to fibers consisting of polypropylene as the fiber comprises 85 wt.% to 98 wt.% of a polypropylene and 2 wt.% to 10 wt.% of a cyclic olefin copolymer can be drawn at a higher draw ratio as compared to fibers consisting of polypropylene, thereby resulting in increased post-crack safety for the fiber reinforced concrete.
  • the fiber has an average creep of 15% or less, more preferably 10% or less. Creep has been determined by image acquisition as the elongation of the fiber after 960 hours of subjecting the fiber to a vertical sustained loading corresponding to 50% of the tensile strength of the fiber. The average value for three fibers is determined.
  • the fiber according to the invention is spun from a blend comprising 85 wt.% to 98 wt.% of a polypropylene and 2 wt.% to 10 wt.% of a cyclic olefin copolymer.
  • polypropylene and 2 wt.% to 10 wt.% of a cyclic olefin copolymer provides a fiber having increased tensile strength as compared to fibers consisting of a
  • polypropylene i.e. not comprising 2 wt.% to 10 wt.% of a cyclic olefin copolymer.
  • the fiber spun from a blend comprising 85 wt.% to 98 wt.% of a polypropylene and 2 wt.% to 10 wt.% of a cyclic olefin copolymer can be drawn at a higher draw ratio thereby enabling to increase the modulus of the fiber.
  • the fiber comprises 88 wt.% to 95 wt.% of the polypropylene to achieve an optimum increase in tensile strength and/or an optimum increase in modulus of the fiber.
  • the fiber comprises 3 wt.% to 8 wt.% of the cyclic olefin copolymer, preferably 4 wt.% to 6 wt.% of the cyclic olefin copolymer, to achieve a higher increase in tensile strength and/or a higher increase in modulus of the fiber.
  • the fiber for concrete reinforcement according to the invention preferably has a tensile strength of at least 600 MPa, preferably at least 650 MPa, more preferably at least 700 MPa as determined according to EN 14889-2.
  • the fiber for concrete reinforcement according to the invention preferably has a modulus of at least 6 GPa, more preferably at least 7 GPa, more preferably at least 8 GPa, even more preferably at least 9 GPa, most preferably at least 10 GPa as determined according to EN 14889-2, wherein the modulus of the fiber is determined between 10% and 30% of the tensile strength of the fiber.
  • the fiber comprising 85 wt.% to 98 wt.% of a polypropylene and 2 wt.% to 10 wt.% of a cyclic olefin copolymer can advantageously be used for concrete
  • reinforcement as the polypropylene and the cyclic olefin copolymer are not susceptible to corrosion, and are durable in highly alkaline environments.
  • the fiber for concrete reinforcement according to the invention comprises 1 wt.% to 5 wt.% of a compatibilizer.
  • a compatibilizer in the blend from which the fiber is spun, increases the tensile strength of fiber at equal draw ratio, and enables to increase the modulus of the fiber at higher draw ratios which could not be applied when spinning a fiber from a blend without the compatibilizer.
  • the compatibilizer reduces the size of cyclic olefin copolymer domains in the blend from which the fiber is spun, thereby creating a larger interfacial area between the polypropylene and the cyclic olefin copolymer in the fiber enabling improved orientation of the polypropylene in the fiber.
  • the compatibilizer may be a styrene-ethylene-butylene-styrene copolymer.
  • the compatibilizer is a maleic acid grafted polymer, preferably a maleic acid grafted polypropylene polymer or a maleic acid grafted styrene-ethylene- butylene-styrene copolymer.
  • the fiber for concrete reinforcement according to the invention comprises an inorganic additive to increase adhesion of the fiber to concrete, the inorganic additive preferably being selected from the group consisting of calcium carbonate, calcium sulphate, talc and barium sulphate.
  • the fiber comprises 1 wt.% to 5 wt.% of inorganic additive.
  • the fiber has an equivalent fiber diameter, as can be calculated from the linear density of the fiber and the material density, of at least 300 pm, preferably in the range of 500 pm to 1000 pm, as determined according to EN 14889-2, to provide sufficient residual flexural tensile strength without adversely affecting the workability of a concrete mixture comprising the fibers.
  • the fiber has a largest dimension, of 2000 pm or less, more preferably 1500 pm or less, the largest dimension being the maximum distance defined by a straight line between two opposing sides of the fiber cross-sectional area, the straight line crossing the center of gravity of the cross-sectional area.
  • Fibers or tapes having a largest dimension higher than 2000 pm can cause problems in handling the concrete mixture, in particular reducing the workability of the concrete mixture, and/or deteriorating the quality of the concrete element.
  • the fiber according to the invention enables to use fibers of smaller equivalent diameter in fiber reinforced concrete at equal post-crack residual flexural tensile strength of the concrete.
  • the fiber may have any cross-sectional shape, including a circular cross-sectional shape, a triangular cross-sectional shape, a multi-lobal cross-sectional shape, such as for example a trilobal cross-sectional shape, or a dog-bone cross- sectional shape.
  • the fiber may also have an asymmetric cross-sectional shape such that the fiber is configured to form a helical structure to increase the friction between the fiber and concrete increasing the strength of the fiber reinforced concrete at a crack mouth opening displacement of 3.5 mm (fR,4).
  • the fiber has a non-circular cross-sectional shape, more preferably a dog-bone cross-sectional shape, to increase the friction between the fiber and concrete increasing the strength of the fiber reinforced concrete at a crack mouth opening displacement of 3.5 mm (fR,4).
  • the fiber preferably has an embossed surface to increase the friction between the fiber and concrete to increase the strength of the fiber reinforced concrete at a crack mouth opening displacement of 3.5 mm (fR,4).
  • the embossing on the surface of the fiber may have any shape, preferably the embossed surface comprises diamond-shaped indentations, preferably in a staggered configuration.
  • the fiber may have a length in the range of 20 mm to 100 mm, preferably in the range of 30 mm to 70 mm, thereby providing sufficient post-crack residual flexural tensile strength in the fiber reinforced concrete while preventing, or at least reducing, problems in handling the concrete mixture comprising the fibers, in particular the workability of the concrete mixture.
  • the fiber for concrete reinforcement comprising 85 wt.% to 98 wt.% of a polypropylene and 2 wt.% to 10 wt.% of a cyclic olefin copolymer enables to provide fiber reinforced concrete having a strength at a crack mouth opening displacement of 3.5 mm (fR,4) which is higher than the strength at a crack mouth opening displacement of 0.5 mm (fR,i ), i.e. having a ratio fR,4/fR,i of more than 1.
  • the polypropylene comprised in the fiber according to the invention may be any polypropylene polymer.
  • the polypropylene polymer has a melt flow index of 10 g/10 min or less, preferably 5 g/10 min or less, more preferably 3 g/10 min or less, as determined in accordance with ISO 1133 at 230°C / 2.16 kg, to further increase the tensile strength of the fiber.
  • the polypropylene comprised in the fiber according to the invention may be an atactic polypropylene polymer, a syndiotactic polypropylene polymer or an isotactic polypropylene polymer, or any copolymer thereof.
  • the polypropylene comprised in the fiber according to the invention is an isotactic polypropylene polymer to further increase the tensile strength of the fiber.
  • Cyclic olefin copolymer is a polymer known to those skilled in the art. Cyclic olefin copolymers are produced by chain copolymerization of cyclic monomers such as for example 8,9,10-trinorborn-2-ene or 1 ,2,3,4,4a,5,8,8a-octahydro- 1 ,4:5,8-dimethanonaphthalene (tetracyclododecene) with ethene, or by ring- opening metathesis polymerization of various cyclic monomers followed by hydrogenation.
  • cyclic monomers such as for example 8,9,10-trinorborn-2-ene or 1 ,2,3,4,4a,5,8,8a-octahydro- 1 ,4:5,8-dimethanonaphthalene (tetracyclododecene) with ethene, or by ring- opening metathesis polymerization of various cyclic monomers followed by hydrogenation
  • the cyclic olefin copolymer comprised in the fiber according to the invention may be any cyclic olefin copolymer.
  • the cyclic olefin copolymer has a melt flow index of 25 g/10 min or less, preferably 20 g/10 min or less, more preferably 15 g/10 min or less, more preferably 10 g/10 min or less, even more preferably 5 g/10 min or less most preferably 3 g/10 min or less as determined in accordance with ISO 1133 at 260°C / 2.16 kg, to further increase the tensile strength of the fiber.
  • the fiber according to the invention can advantageously be used to provide a fiber reinforced concrete (FRC) element.
  • FRC fiber reinforced concrete
  • the concrete element preferably comprises fibers according to any of the embodiments of the fiber above.
  • the fiber for concrete reinforcement according to the invention enables to reduce the amount of fibers in fiber reinforced concrete without adversely affecting the properties of the concrete.
  • the fiber reinforced concrete comprises the fibers in an amount of 10 kg/m 3 or less, more preferably in an amount of 5 kg/m 3 or less, even more preferably in an amount of 4 kg/m 3 or less, most preferably in an amount of 3 kg/m 3 or less to prevent, or at least reduce, problems in handling the concrete mixture comprising the fibers, in particular the workability of the concrete mixture, and/or to improve the quality of the concrete element.
  • the fiber for concrete reinforcement according to the invention enables to provide fiber reinforced concrete having a residual flexural tensile strength at a crack mouth opening displacement of 0.5 mm (fR,i) of at least 1.5 MPa, the fiber reinforced concrete preferably comprising the fibers in an amount of 10 kg/m 3 or less, more preferably in an amount of 5 kg/m 3 or less, even more preferably in an amount of 4 kg/m 3 or less, most preferably in an amount of 3 kg/m 3 or less.
  • the fiber for concrete reinforcement according to the invention enables to provide fiber reinforced concrete having a residual flexural tensile strength at a crack mouth opening displacement of 3.5 mm (fR,4) of at least 1.0 MPa, the fiber reinforced concrete preferably comprising the fibers in an amount of 10 kg/m 3 or less, more preferably in an amount of 5 kg/m 3 or less, even more preferably in an amount of 4 kg/m 3 or less, most preferably in an amount of 3 kg/m 3 or less.
  • the fiber for concrete reinforcement according to the invention enables to provide fiber reinforced concrete having a total energy absorption of at least 950 J, preferably at least 1000 J, more preferably at least 1050 J, as determined according to EN 14488-5, the fiber reinforced concrete preferably comprising the fibers in an amount of 10 kg/m 3 or less, more preferably in an amount of 5 kg/m 3 or less, even more preferably in an amount of 4 kg/m 3 or less.
  • a process for manufacturing the fiber for concrete reinforcement according to the invention comprises the steps of supplying a blend 85 wt.% to 98 wt.% of a polypropylene, 2 wt.% to 10 wt.% of a cyclic olefin copolymer, and up to 5 wt.% of a compatibilizer into an extruder, extruding the blend through a spinneret comprising one or more capillaries to form one or more extruded fibers, cooling the extruded fibers, drawing the extruded fibers, preferably at a draw ratio of at least
  • the process for manufacturing the fiber according to the invention comprises the step of drawing the extruded fiber at a draw ratio of at least 10 to form the fiber for concrete reinforcement.
  • manufacturing the fiber according to the invention comprises the step of drawing the extruded fiber at a draw ratio of at least 11 , more preferably at a draw ratio of at least 12, even more preferably at a draw ratio of at least 13.
  • a draw ratio of at least 11 By extruding a blend comprising supplying a blend comprising 85 wt.% to 98 wt.% of a polypropylene and 2 wt.% to 10 wt.% of a cyclic olefin copolymer, the extruded fiber can be drawn at a higher draw ratio as compared to a fiber consisting of a polypropylene.
  • the process for manufacturing the fiber according to the invention comprises the step of cutting the fiber for concrete reinforcement to a specified length, preferably to a length in the range of 20 mm to 100 mm, preferably in the range of 30 mm to 70 mm.
  • the process for manufacturing the fiber according to the invention comprises the step of supplying a blend into an extruder, the blend comprising 88 wt.% to 95 wt.% of the polypropylene to achieve an optimum increase in tensile strength and/or an optimum increase in modulus of the fiber.
  • the process for manufacturing the fiber according to the invention comprises the step of supplying a blend into an extruder, the blend comprising 3 wt.% to 8 wt.% of the cyclic olefin copolymer, preferably 4 wt.% to 6 wt.% of the cyclic olefin copolymer to achieve the highest increase in tensile strength and/or increase in modulus of the fiber.
  • the fiber according to invention can be obtained by the process wherein the polypropylene and the cyclic olefin copolymer are supplied into a single screw extruder.
  • a single screw extruder is known for not thoroughly mixing a two or more polymers, an improved fiber is nevertheless obtained.
  • the process for manufacturing the fiber according to the invention comprises the step of supplying a blend into an extruder, the blend comprising 1 wt.% to 5 wt.% of a compatibilizer, enabling to apply a higher draw ratio to the extruded fiber.
  • the compatibilizer may be a styrene-ethylene-butylene-styrene copolymer.
  • the compatibilizer is a maleic acid grafted polymer, preferably a maleic acid grafted polypropylene polymer or a maleic acid grafted styrene-ethylene- butylene-styrene copolymer.
  • the process for manufacturing the fiber according to the invention comprises the step of supplying a blend into an extruder, the blend comprising an inorganic additive to increase adhesion of the fiber to concrete, the inorganic additive preferably being selected from the group consisting of calcium carbonate, calcium sulphate, talc and barium sulphate.
  • the fiber comprises 1 wt.% to 5 wt.% of inorganic additive.
  • the process for manufacturing the fiber according to the invention comprises the step of drawing the extruded fiber at a draw ratio such that the fiber has an equivalent fiber diameter of at least 300 pm, preferably in the range of 500 pm to 1000 pm, as determined according to EN 14889-2.
  • the fiber has a largest dimension, of 2000 pm or less, more preferably 1500 pm or less.
  • the process for manufacturing the fiber according to the invention comprises the step of extruding the blend through a spinneret comprising one or more capillaries to form one or more extruded fibers, wherein the capillaries have a circular cross-sectional shape, a triangular cross-sectional shape, a multi-lobal cross-sectional shape, such as for example a trilobal cross-sectional shape, or a dog-bone cross-sectional shape, preferably a non-circular cross-sectional shape, more preferably a dog-bone cross-sectional shape.
  • a fiber having a non-circular cross-sectional shape can be heated more efficiently thereby enabling to apply a higher draw ratio.
  • the process for manufacturing the fiber according to the invention comprises the step of embossing the extruded fiber, preferably with diamond- shaped indentations, preferably in a staggered configuration.
  • the process for manufacturing the fiber according to the invention comprises the step of cutting the fiber to a predefined length, preferably to a length in the range of 20 mm to 100 mm, preferably in the range of 30 mm to 70 mm.
  • the process for manufacturing the fiber according to the invention comprises the step of supplying a blend comprising 85 wt.% to 98 wt.% of a polypropylene, 2 wt.% to 10 wt.% of a cyclic olefin copolymer, wherein the polypropylene polymer has a melt flow index of 10 g/10 min or less, preferably 5 g/10 min or less, more preferably 3 g/10 min or less, as determined in accordance with ISO 1133 at 230°C / 2.16 kg, to further increase the tensile strength of the fiber.
  • the polypropylene supplied in the process according to the invention may be an atactic polypropylene polymer, a syndiotactic polypropylene polymer or an isotactic polypropylene polymer.
  • the polypropylene supplied in the process according to the invention is an isotactic polypropylene polymer to further increase the tensile strength of the fiber.
  • Comparative Example 1 Fibers were spun from a blend of 95.5 wt.% of a polypropylene, 3.5 wt.% of an inorganic filler, and 1 wt.% of nucleating agent.
  • Fibers were spun under the same conditions of Comparative Example 1 , except that the fibers were spun from a blend of 95 wt.% of a polypropylene and 5 wt.% of a cyclic olefin copolymer. The fibers were drawn at a draw ratio of 14 and had an equivalent diameter of 0.70 mm.
  • Table 1 the creep of the fiber of example 1 has been compared to the creep of the fiber of comparative example 1.
  • Table 1 and Figure 1 a-b show that the creep of fiber according to example 1 is reduced by 29% as compared to the fiber according to comparative example 1.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Structural Engineering (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Textile Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Composite Materials (AREA)
  • Manufacturing & Machinery (AREA)
  • Artificial Filaments (AREA)

Abstract

L'invention concerne une fibre pour armature de béton, comprenant 85 % en poids à 98 % en poids d'un polypropylène, 2 % en poids à 10 % en poids d'un copolymère d'oléfine cyclique et jusqu'à 5 % en poids d'un agent de compatibilité, la fibre présentant une résistance à la traction d'au moins 600 MPa et un module d'au moins 6 GPa.
EP19758782.7A 2018-10-31 2019-08-29 Fibre pour armature de béton Pending EP3873871A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP18203641 2018-10-31
PCT/EP2019/073122 WO2020088822A1 (fr) 2018-10-31 2019-08-29 Fibre pour armature de béton

Publications (1)

Publication Number Publication Date
EP3873871A1 true EP3873871A1 (fr) 2021-09-08

Family

ID=64362305

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19758782.7A Pending EP3873871A1 (fr) 2018-10-31 2019-08-29 Fibre pour armature de béton

Country Status (2)

Country Link
EP (1) EP3873871A1 (fr)
WO (1) WO2020088822A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE1029136B1 (nl) * 2021-12-24 2022-09-21 Adfil Vezel voor betonversterking

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3173897B2 (ja) * 1992-11-10 2001-06-04 三井化学株式会社 環状オレフィン系樹脂繊維およびその製造方法
US7695812B2 (en) * 2005-09-16 2010-04-13 Dow Global Technologies, Inc. Fibers made from copolymers of ethylene/α-olefins

Also Published As

Publication number Publication date
WO2020088822A1 (fr) 2020-05-07

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