Patent EP0223291A2 successfully refreshed from Google Patents.
EP0223291A2
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Reinforcing element of synthetic material for use in reinforced concrete, more particularly prestressed concrete, reinforced concrete provided with such reinforcing elements, and processes of manufacturing reinforcing elements, and reinforced and prestressed concrete
Assignee: Akzo NV
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Filing: 1986-11-05
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Granted: —
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Expires: 2006-11-05
Abstract
Abstract The invention relates to a reinforcing strip (1) applicable in reinforced concrete, more particularly prestressed concrete, formed by a matrix based on a thermosetting synthetic material in which preferably more than 15000 practically parallel continuous filaments (5) are obtained. The filaments (5) are formed from an organic polymer selected from the group of aromatic polyamides, such as polyparaphenylene terephthalamide, or from polyethylene, polyvinyl alcohol or polyacrylonitrile via solvent spinning. The matrix is formed from a synthetic material based on epoxy resin and/or bismaleimide resin. The reinforcing strip (1) has an improved resistance to alkali. The invention also relates to reinforced concrete comprising said strips (1).
Inventors
- 👤 Hans-Jürgen Schürhoff
- 👤 Arie Gerritse
- 👤 Lambertus Cornelis Mets
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 08:17
CPC Classifications
E; E04; E04C; E04C5/00; E04C5/07; E04C5/073; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2933; Y10T428/2964; Y10T428/2967; Y10T428/2969
Claims Analysis
Total Claims: 45
Claim 1
Independent Claim
185 words
A reinforcing element applicable in reinforced concrete, more particularly prestressed concrete, formed by a matrix based on a thermosetting synthetic material in which more than 5000 practically parallel continuous filaments are contained, characterized in that -the filaments are formed from an organic polymer selected from the group of aromatic polyamides, such as polyparaphenylene terephthalamide, or from polyethylene, polyvinyl alcohol or polyacrylonitrile via solvent spinning, -the matrix is formed from a synthetic material based on epoxy resin and/or bismaleimide resin, -the section transverse to the longitudinal direction of the reinforcing element is substantially rectangular, -the tensile strength of the filament band in the reinforcing element is higher than 2,0 GPa, -the modulus of elasticity of the filament band in the reinforcing element is higher than 60 GPa, -the elongation at rupture of the filament band in the reinforcing element is less than 6%-7%, -the resistance to alkali of the reinforcing element determined by the method defined in the description is such that after 180 days at 80°C the residual strength of the filament band in the reinforcing element is more than 40% of the initial strength.
Claim 2
Dependent Claim
185 words
A reinforcing element applicable in reinforced concrete, more particularly prestressed concrete, formed by a matrix based on a thermosetting synthetic material in which more than 5000 practically parallel continuous filaments are contained, characterized in that -the filaments are formed from an organic polymer selected from the group of aromatic polyamides, such as polyparaphenylene terephthalamide, or from polyethylene, polyvinyl alcohol or polyacrylonitrile via solvent spinning, -the matrix is formed from a synthetic material based on epoxy resin and/or bismaleimide resin, -the section transverse to the longitudinal direction of the reinforcing element is substantially rectangular, -the tensile strength of the filament band in the reinforcing element is higher than 2,0 GPa, -the modulus of elasticity of the filament band in the reinforcing element is higher than 60 GPa, -the elongation at rupture of the filament band in the reinforcing element is less than 6%-7%, -the resistance to alkali of the reinforcing element determined by the method defined in the description is such that after 180 days at 80°C the residual strength of the filament band in the reinforcing element is more than 40% of the initial strength.
Claim 3
Dependent Claim
43 words
A reinforcing element according to claim 1, characterized in that said resistance to alkali of the reinforcing element is such that after 180 days at 80°C the residual strength of the filament band is 60-100%, more particularly about 80-100% of the initial strength.
Claim 4
Dependent Claim
64 words
A reinforcing element according to claim 1, characterized in that -the tensile strength of the filament band in the reinforcing element is 2,2-4 GPa, preferably about 3 GPa, -the modulus of elasticity of the filament band in the reinforcing element is 100-200 GPa, -the elongation at rupture of the filament band in the reinforcing element is higher than 1,5%, and is preferably about 2,0-4%.
Claim 5
Dependent Claim
49 words
A reinforcing element according to claim 1, characterized in that the filaments form not more than 90% by volume, more particularly 40 to 70% by volume, of the reinforcing element and the synthetic matrix material forms at least 10% by volume, more particularly 60 to 30% by volume thereof.
Claim 6
Dependent Claim
18 words
A reinforcing element according to claim 1, characterized in that the epoxy resin is of the novolak type.
Claim 7
Dependent Claim
23 words
A reinforcing element according to claim 1, characterized in that the epoxy resin is a resin based on diglycidyl ether of bisphenol A.
Claim 8
Dependent Claim
26 words
A reinforcing element according to claim 1, characterized in that the epoxy resin is a resin based on a tetrafunctional epoxy resin, such as N,N,N'N'-tetraglycidyl-4,4'-methylene bisbenzenamine.
Claim 9
Dependent Claim
20 words
A reinforcing element according to claim 1, characterized in that the bismaleimide resin is a resin based on 4,4'-bismaleimidodiphenyl methane.
Claim 10
Dependent Claim
35 words
A reinforcing element according to claim 8, characterized in that in addition to 4,4-bismaleimido diphenyl methane the synthetic matrix contains some amount of allyl phenol, for instance in the ratio of 100:75 parts by weight.
Claim 11
Dependent Claim
36 words
A reinforcing element according to claim 1, characterized in that for hardening the epoxy resin use is made of an amine curing agent, such as a cycloaliphatic amine, an aromatic amine, a polyamine or a dicyandiamine.
Claim 12
Dependent Claim
31 words
A reinforcing element according to claim 1, characterized in that to the synthetic resin there may be added an accelerator, such as an accelerator based on BF,, imidazole or dimethyl urea.
Claim 13
Dependent Claim
24 words
A reinforcing element according to claim 1, characterized in that the diameter of the filaments is 5 to 20 um, preferably about 12 u.m.
Claim 14
Dependent Claim
33 words
A reinforcing element according to claim 1, characterized in that in any random section transverse to the longitudinal direction of the reinforcing element the volume of hollow space is less than 1 %.
Claim 15
Dependent Claim
32 words
A reinforcing element according to claim 1, characterized in that of .the flattened, approximately rectangular cross-section of the reinforcing element the ratio of the thickness to the width is less than 1:2.
Claim 16
Dependent Claim
34 words
A reinforcing element according to claim 14, characterized in that the ratio of the thickness to the width of the reinforcing element is in the range of 1:8 to 1:9, preferably 1:8 to 1:20.
Claim 17
Dependent Claim
49 words
A reinforcing element according to claim 1, characterized in that the width of the reinforcing element is in the range of 10 to 50 mm, and is preferably about 20 mm, and the thickness is in the range of 1 to 3 mm, and is preferably about 1,5 mm.
Claim 18
Dependent Claim
36 words
A reinforcing element according to claim 12, characterized in that viewed in transverse direction of the reinforcing element the number of filaments is 3000 to 20 000 per mm, preferably about 5000-10 000 filaments per mm.
Claim 19
Dependent Claim
27 words
A reinforcing element according to claim 1, characterized in that the specific mass of the reinforcing element is 1100 to 1500 kg/m', preferably about 1300 kg/m 3.
Claim 20
Dependent Claim
25 words
A reinforcing element according to claim 1, characterized in that for the purpose of improving adhesion the outer surface of the reinforcing element is rough.
Claim 21
Dependent Claim
25 words
A reinforcing element according to claim 19, characterized in that the rough surface consists of a great many irregularities which are introduced particularly by rolling.
Claim 22
Dependent Claim
42 words
A reinforcing element according to claim 19, characterized in that the outer surface of the reinforcing element contains a great many projec ting fine-grained particles, in particular of inorganic material, such as particles based on silicon oxide, titanium oxide or aluminium oxide.
Claim 23
Dependent Claim
40 words
A reinforcing element according to claim 1, characterized in that the total tensile strength of the filament band in the reinforcing element is higher, preferably 5 to 20%, than the sum of the tensile strength of the non-impregnated filament band.
Claim 24
Dependent Claim
99 words
A process for manufacturing the reinforcing element according to claim 1, in which process more than 5000 practically parallel filaments are collectively embedded in a liquid synthetic material which is to serve as matrix, which is subsequently cured, particularly by subjecting it to a heat treatment, characterized in that use is made of filaments formed from an organic polymer selected from the group of aromatic polyamides, such as polyparaphenylene terepthalamid, or from polyethylene, polyvinyl alcohol or polyacrylonitrile via solvent spinning and use is made of a matrix formed from a synthetic material based on epoxy resin and/or bismaleimide resin.
Claim 25
Dependent Claim
40 words
A process according to claim 23, characterized in that use is made of an epoxy resin of the novolak type or an epoxy resin based on diglycidyl ether of bisphenol A or a tetrafunctional epoxy resin, such as N,N,N'N'-tetraglycidyl-4,4'-methylene bisbenzeneamine.
Claim 26
Dependent Claim
25 words
A process according to claim 23, characterized in that use is made of a bismaleimide resin which is a resin based on 4,4-bismaleimide diphenyl methane.
Claim 27
Dependent Claim
43 words
A process according to claim 25, characterized in that use is made of a synthetic matrix which is formed by a resin based on 4,4-bismaleimidodiphenyl methane supplemented with some amount of allyl phenol, for instance in the ratio of 100:75 parts by weight.
Claim 28
Dependent Claim
61 words
A process according to claim 23, characterized in that the liquid epoxy resin with which the filaments are impregnated contains an amine hardener, such as a cycloaliphatic amine, an aromatic amine, a poly amine or a dicyandiamine, the epoxy resin and the amine hardener being used in amounts by weight in a ratio which for instance ranges from 100:20 to 100:40.
Claim 29
Dependent Claim
23 words
A process according to claim 23, characterized in that use is made of a catalytic hardener, such as a hardener based on BF3.
Claim 30
Dependent Claim
29 words
A process according to claim 23, characterized in that to the synthetic matrix there is added an accelerator, such as an accelerator based on BF,, imidazole or dimethyl urea.
Claim 31
Dependent Claim
82 words
A process according to claim 23, characterized in that said embedding is effected by passing a filament bed having a width of at least 5 mm and a thickness of preferably not more than 3 mm under one or more preferably trough-shaped metering devices from which the mixture of liquid matrix resin is fed to the filament bed and in that the thus impregnated filament bed is passed through a curing zone for the resin preferably while subjected to a heat treatment.
Claim 32
Dependent Claim
34 words
A process according to claim 30, characterized in that the filament bed is preheated, for instance to a temperature of 30° to 70°C before the matrix resin comes into contact with the filament bed.
Claim 33
Dependent Claim
29 words
A process according to claim 30, characterized in that the matrix resin is preheated to a temperature of, for instance, 30°-70°C before it flows out of the metering device.
Claim 34
Dependent Claim
28 words
A process according to claim 30, characterized in that the filament bed provided with resin is heated to a temperature of 35°-70°C before it reaches the curing zone.
Claim 35
Dependent Claim
41 words
A process according to claim 30, characterized in that the widest side face of a formed, partly cured strip-shaped reinforcing element is bonded to one or more, preferably two, other identical strip-shaped reinforcing elements, preferably by means of the matrix resin.
Claim 36
Dependent Claim
58 words
A process according to claim 30, characterized in that two at least partly cured or wet practically uncured strip-shaped reinforcing elements may with advantage each be attached to a different side of a reinforcing element by means of a still wet, practically uncured resin, after which the three reinforcing elements thus joined are passed through a curing zone.
Claim 37
Dependent Claim
42 words
A process according to claim 30, characterized in that prior to being completely cured the reinforcing element is gauged more particularly by means of transporting gauging rolls which are provided with recesses that correspond to the desired cross-section of the reinforcing element.
Claim 38
Dependent Claim
30 words
Reinforced concrete, more particularly prestressed concrete, characterized in that the reinforcement is formed by one or more of the reinforcing elements according to one or more of the claims 1-22.
Claim 39
Dependent Claim
43 words
Concrete according to claim 37, characterized in that the ratio of the modulus of elasticity of the concrete matrix to the modulus of elasticity of the filament band in the reinforcing element is in the range of 1:2 to 1:6, preferably about 1:4.
Claim 40
Dependent Claim
39 words
Concrete according to claim 37, characterized in that prior to curing there is added to the concrete mortar a chloride-containing curing accelerator, preferably: 0,5 to 7% by weight of CaCl,, calculated on the cement weight in the concrete matrix.
Claim 41
Dependent Claim
47 words
Concrete according to claim 37, characterized in that the covering thickness of the concrete matrix measured between the outer surface of the concrete matrix and the circumferential surface of the reinforcing element is in the range of 0 to less than 15 mm, preferably about 2-5 mm.
Claim 42
Dependent Claim
35 words
Concrete according to claim 37, characterized in that a number of reinforcing elements extend parallel to and at some distance from each other and substantially rectilinear in practically the same plane in the concrete matrix.
Claim 43
Dependent Claim
62 words
A process of preparing reinforced concrete, particularly prestressed concrete, according to claim 37, the reinforcement being placed in a form into which subsequently. the concrete mortar is poured, charac terized in that the reinforcement is formed by one or more of the reinforcing elements according to the claims 1-22 and the concrete mortar is brought into direct contact with the reinforced elements.
Claim 44
Dependent Claim
36 words
A process according to claim 42, characterized in that the concrete mortar contains a chloride-containing hardening accelerator, more particularly 0,5-7% by weight of CaCI 2 , calculated on the cement weight in the cured concrete matrix.
Claim 45
Dependent Claim
94 words
A process for the preparation of prestressed concrete according to claim 42, in which process prior to the curing of the concrete matrix each of the reinforcing elements is pretensioned while subjected to an external tensile load, said external tensile load being removed after the curing of the concrete matrix, characterized in that an external tensile load of such magnitude is applied that in the cured concrete matrix the tensile stress in each reinforcing element is 40 to 70%, preferably about 50%, of the tensile strength of the filament band in the reinforcing element.
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