DE69928741T2 - Reinforcing fabrics for buildings - Google Patents

Abstract

Fabric suitable to the application as reinforcement of building works, wherein the warp consists of threads of fibers having high modulus and the weft consists of glass threads coated with thermoadhesive <IMAGE>

Description

State of technology

method for reinforcement of building structures such as brick walls, Stone walls, Reinforced concrete structures, vaults, Wall piers, supporting beams, galleries, supporting walls, etc. using Fibers or reinforcing fabrics that are designed to be using a coating and impregnation technique with resins from Thermoset type adhesive are well known in the art.

One the first method is in Swiss patent CH-365517 of August 11th 1960, which claims the protection for the reinforcement of Parts made of unreinforced concrete or stone material by the application of fibers and fabrics with synthetic resin on the surface.

Subsequently, several types of reinforcement have been developed, which enable the reinforcement of several types of structures using the normal manual coating techniques well known in the field of composites (contact methods in the processing of thermosets). For example, in the patent EP 0441519 B1 dated 30.01.1991 and in the patent EP 598591 A of 25.05.1994 (Tonen Corp. Patents) claims protection for a reinforcing member for reinforced concrete structures which consists essentially of a web of reinforcing fibers running in the same direction, which are connected by a thin net of plastic adhesive and of one Web be worn from silicone paper.

Also if this procedure over has been used for a certain period of time, it has considerable Disadvantages: show the perfectly aligned fibers no porosity, and they enable not the escape of the air while the coating; it turns out that arranged in this way Fibers which are connected by the net on only one side during the Installation are very difficult to handle, which is why they are always from a paper (silicone-treated paper) or an inert paper Foil must be worn.

These Fact hindering the unfolding of handicrafts during the Installation, which de facto reduces the size of the railway, which can be coated, reduced to a length of 2 meters becomes.

The patent EP 9628117B of 20.01.1993 (Hexcell Patent) claims protection for reinforcement of columns by coating with resin-impregnated fabrics, such fabrics being characterized in that the warp is arranged perpendicular to the column axis and the weft is parallel to the column axis. Otherwise, the reinforcing fibers may be disposed at angles which are between 20 ° and 70 ° with respect to the column axis and between -20 ° and -70 ° with respect to the direction perpendicular to the column axis.

Further can the fibers are connected to each other with auxiliary seams.

This Patent leads to a limited reinforcing effect due to the imperfect linear alignment of the fibers, which, being under different Angle are arranged, not all for reinforcing effect in the desired Contribute direction.

The British Patent 2,295,637A (Sho Bond Corp.) of 12.02.1994 a method for reinforcing reinforced concrete structures by coating by means of a reinforcing fiber in the form of a fabric, wherein the fiber is in one direction is arranged running and which with auxiliary threads in the weft and in the warp which is connected by the fact that they are interconnected are, in the same direction extending reinforcing fibers in the desired Hold position. As a help thread can thermoplastic polymer threads which are used under heat treatment with each other connect.

This Process turns out to be quite complex, since the introduction of auxiliary threads considerable in the web chain Complications in the production of the tissue brings with it. About that addition, only the auxiliary threads connect with each other, and the reinforcing fibers be only through the auxiliary threads held, and in the case of the use of thermoplastic polymer threads there it after melting heat treatment from these only partially hot-welded points. This is all possible the stability the railway and its installation severely impair.

The patent EP 3782232 A dated Jul. 18, 1990 (Mitsubishi patent) discloses the application of prepregs to building structures with the aid of an adhesive.

Of the Adhesive and the pre-impregnated Resin are cured together one after the other.

This Process has all the disadvantages typical of prepregs (storage at low temperature, limited life and high cost), and also requires the use of an adhesive, what with further complications associated with the application.

EP 859085 discloses a method of reinforcing building structures in which a material is applied by means of impregnating resins and this material comprises reinforcing fibers arranged along one direction and heat sealable fibers arranged perpendicular to the reinforcing fibers. In all examples, the heat sealable fibers are obtained by blending high melting point fibers with low melting point fibers which are twisted together. An adhesive resin is also included in the heat sealable fibers. The process of making this material is quite complex and the orientation of the reinforcing fibers is not completely satisfactory.

Presentation of the invention

The The main object of the present invention is a heat-treated Tissue used for the Application is suitable as a reinforcing material for buildings and allows overcome the disadvantages of the prior art and the building high To give properties in terms of its mechanical strength, and we have found such a tissue.

The called tissue is characterized by the fact that the warp Threads of Consists fibers, which have a high modulus, namely a modulus of elasticity under tension greater than 10 GPa (Gigapascal) and a tensile load greater than 600 MPa (Megapascal), and that the shot consists of threads that with a thermoadhesive coated polymeric material wherein said fabric is optionally reinforced with filaments of fibers can, which has the same characteristics and the same direction as the warp threads exhibit.

The The invention also includes a method for applying said Fabric on structures.

Short description of pictures

1 shows an embodiment of the tissue in which 11 ) the warp threads and with ( 12 ) are designated the weft threads.

1A . 1B . 1C and 1D illustrate alternative embodiments of the fabric with different arrangement of warp and weft.

2 shows a detail of a weft.

3 shows another embodiment of the tissue in which 31 ) the reinforcing threads are designated.

4 shows the tissue of 3 on average.

5 represents two applied to a concrete structure tissue layers.

6 shows the device used for the production of in the 3 and 4 represented tissue was used.

Detailed description the invention

The The present invention relates to a fabric for reinforcing masonry, Concrete, concrete and reinforced concrete structures and in particular a heat treated Tissue in which the warp is made of filaments of high-denier fibers Module and the weft of glass threads which are coated with a thermoadhesive polymeric material.

The Invention relates to this In addition, a method for applying the said fabric to buildings.

The tissue preferably has the in 1 reproduced configuration, in which ( 46 ) in general represents the tissue, 11 ) represents the filaments of the highly modular fibers arranged in the chain and ( 12 ) represents those threads which are coated with a thermoadhesive polymeric material and arranged in a weft.

In 2 is the thread ( 12 ) in detail, wherein ( 21 ) represents the glass thread and ( 22 ) represents the coating consisting of a thermoadhesive polymeric material.

It turns out that the fabric, after being subjected to the heat treatment with melting of the thermoadhesive polymeric material along the entire course of the weft, is completely heat-set and shows a high dimensional stability with a complete locking of the warp threads, which also during the subsequent processing steps maintain their position in the desired direction. In the presentation of the 1 is the arrangement of the weft in relation to the chain of a flat type, but it can be of any kind according to the techniques well known to those skilled in the field of weaving (twill weave, batavia weave, panama weave, mat weave), with different arrangement of the weft in terms of the warp.

Examples of the different types of arrangements are in the 1A . 1B . 1C and 1D shown.

The warp threads ( 11 ) of the 1 may vary from 1 filament / cm to 12 filaments / cm, and preferably from 2 filaments / cm to 8 filaments / cm, depending on the typology of the spun yarn.

The warp threads ( 11 ) may have different deniers (denier values), which may be in the range of 20 Tex to 10,000 Tex, and preferably 40 to 1,000 Tex, expressed in Tex (weight in grams per 1,000 m of thread).

The detail in 2 shown weft thread ( 12 ) consists of one with ( 21 ) with a low characteristic value, which is preferably in the range of 20 to 100 Tex and which externally with a thermoadhesive polymer ( 22 ), wherein the amount of thermoadhesive polymer is in a range of 10 to 300% with respect to the weight of the glass.

To the Example is a weft thread used in the present invention from a 60-Tex glass thread, which with a thermoadhesive polymer covered by 40 Tex is, where the total weight of the thread is equal to 100 Tex.

For the goals In the invention, the use of a coated glass thread is best suitable, but you can also coated Use threads, which are made of other materials (carbon, polyester, polyarylamides, Aramids, etc.).

The Coating with the thermoadhesive polymer can be achieved in various ways such as by multilayer extrusion or by coupling with a thermoadhesive polymer in any way

The distribution of the thermoadhesive polymer ( 22 ) on the thread ( 21 ) may be of any type, but preferably the said distribution over the entire length of the thread ( 21 ) continuously.

The thermoadhesive polymers which are used for coating the glass thread ( 21 ) are class of polyolefin, polyvinyl, polyamide, polyester and polyurethane polymers and copolymers well known in the art of thermoadhesive polymers (hot melt adhesives) and characterized by a melting temperature, which is in a range of 40 to 250 ° C, and preferably 80 to 200 ° C. In a further embodiment of the invention, the tissue of the 1 are connected with a series of filaments of high modulus fibers, which on one side of the fabric of the 1 parallel to the web chain ( 11 ) are arranged on this side by a heat weldable weft thread ( 12 ) are heat-set. In this way you reach the in 3 (perspective view) and in 4 (Section) shown structure, which consists essentially of the tissue of 1 consists of reinforcing threads ( 31 ), which are along the direction of the warp ( 11 ) and in such a position by the thermal adhesion of the weft thread ( 12 ) of the tissue 1 being held.

The in the 1 . 1A . 1B . 1C and 1D Tissues shown can show the two surfaces that are perfectly symmetrical and equal to each other, such as the one in the 1 . 1B and 1C whereas other fabrics may have two fabric sides which are different from each other, and more particularly a side which is richer in weft yarns, ie a side on which the weft yarn occurs more frequently and a side which is poorer in weft yarns on which the weft occurs less frequently, such as in the 1A and 1D ,

With ( 11 ) and with ( 31 ) are high modulus fibers characterized by having a tensile modulus greater than 10 GPa (gigapascals) and a tensile strength greater than 600 MPa (megapascals), exhibit.

such Fibers fall into the following material groups: rayon fibers, high modulus polyester fibers, polyvinyl alcohol fibers, polyethylene fibers, Aramid fibers, carbon fibers, glass fibers, fibers of liquid crystal polymers.

This with 11 ) and ( 31 ) threads can be equal to each other or of different nature and labeling (Hygienweb) be. For example, one can simultaneously use carbon fibers, glass fibers, aramid fibers and polyester fibers in the same structure.

The Fabric according to the present invention Invention find application for the reinforcement of structures by impregnating resins, to which all synthetic resins belong, which generally for the production of components used in a composite material especially polyester resins, vinyl ester resins, phenolic resins, Epoxy resins, polyurethane resins, acrylic resins, bismaleimide resins.

Furthermore can the said fabrics also in the production of composite materials be used.

The commonplace Method for applying the fabrics for the coating of structures is well known and is usually made by manual coating (hand application) of the fabric and by impregnation with the ones listed above Synthetic resins executed.

In front It is generally advisable to do a thorough job of applying the tissues cleaning the surface to be treated and then carry out the following operations like this Distributing a first (already catalyzed) synthetic resin layer for curing, Applying the fabric, spreading a second layer of synthetic resin around the complete impregnation of the tissue, and application of possible further tissue layers Repeating the above operations.

The curing of the synthetic resin is carried out by means of those techniques well known to those skilled in the art, in general at temperatures that correspond to a range of 5 to 40 ° C lie the resin system used.

The Number and arrangement of the applied tissue varies in dependence from the reinforcing effect, which one wants to achieve, and the shape and structure of the component being reinforced should.

The Method of applying the tissue to the surface of building bodies according to the present Invention includes the sequence of the following operations: application a layer of impregnating resin on said surface, application of the tissue in the reinforced Form, application of a second layer of impregnating resin, application of the Tissue in unreinforced form and applying a third layer of impregnating resin.

In a preferred embodiment of the invention, the first tissue, which is applied to the surface to be reinforced, of the in the 3 and 4 it should be noted that the side B of the fabric itself is brought into contact with the surface to be treated according to the configuration of 5 , in which also a subsequent tissue of the type of 1 is shown.

It should be now 5 be considered more closely: 41 ) is a concrete component to be reinforced, 42 ) is the first layer of impregnating resin, ( 45 ) is the tissue of the 3 and 4 which is applied to the concrete surface so that the side B ( 43 ) is directed to the unreinforced concrete and the side A ( 44 ) to the outside, ( 47 ) is a second layer of impregnating resin, ( 46 ) is a second layer of a fabric accordingly 1 , and ( 48 ) is another layer of impregnating resin.

This application configuration is optimal to achieve the maximum of the reinforcing effect, with the side B of the fabric of the 3 and 4 in contact with the surface to be reinforced in the limitation of superficial "cracks" and their propagation produces the best effect.

The Side A has a high reinforcing effect.

The tissues containing the in 1 have shown structure and subsequently applied, exert a high reinforcing effect.

In a second preferred embodiment, the fabrics may be of the type described in U.S. Pat 1 shown type can be applied directly to the surface to be reinforced. In the case of fabrics in which the two sides are equal to each other, such as those of the 1 . 1B and 1C , there is no preferable side for the application, but it is in the case of such fabrics, which have two different sides, such as the fabric of the 1A and 1D , an advantage if you apply the fabric with the side that is poorer on weft threads on the surface to be reinforced.

One further advantage of the fabrics according to the present invention Invention is that applied to them a plaster layer can be what often under aesthetic Viewpoints of great Meaning is.

The The following examples are presented by way of illustration become.

Example 1 (example of the production of the fabric of 1 )

1a - tissue production:

In a Dornier loom Mod. HTV4 / SD, which has a positive lance Pliers has a creel is installed, whereupon 380 spools with Carbon fibers 12K grade with a rating of 800 Tex.

This Anchor gate is used to feed the warp threads of the loom. The shot the loom is fed with a glass thread with the characteristic 60 Tex, which was coated with a copolyamide hot melt adhesive 40 Tex is, which has a melting temperature of about 160 ° C.

The loom works with 3.8 threads / cm in the warp and with 2 insertions of the weft per cm.

It is made a fabric which has a height of 100 cm. This is wound up in the form of rolls. The fabric shows a structure consisting in the warp of 3.8 threads / cm of 12 K carbon threads and in the weft of 2 threads / cm glass thread which is coated with a hot melt adhesive. The weight of this fabric is 324 g / m ² .

1b - heat treatment

In a device consisting of an unwinding device, an infrared heating system and a rewinding machine, the fabric undergoes a heat treatment. The infrared radiation heating system is at a temperature adjusted so that at a tissue, which at a speed running at 6 meters / minute, the melting of the thermoplastic polymer (hot melt adhesive), with which the weft thread covered is achieved.

To the heat treatment and the subsequent one Cooling the fabric is rolled up and it shows completely solidified, wherein the weft thread is glued to the warp threads hot.

The fabric obtained in this way has the following properties:
Weight = 324 g / m ² , tensile strength in the direction of the chain> 600 N / mm over the fabric width, Young's modulus under tensile stress in the direction of the warp = 40 kN / mm over the fabric width.

Example 2 (example of the production of the fabric of the 3 and 4 )

A fabric prepared as described in item 1a of Example 1, weighing 324 g / m ² , is treated as described in item 1b of Example 1 for the purpose of thermal reinforcement. To the fabric treated in this way, for the purpose of reinforcing it, carbon threads 800 Tex 12K are coupled in a number of 3.8 threads / cm parallel to the warp threads, using a device as shown schematically in FIG 6 is shown. In the above figure, 51 ) the tissue unwinder ( 46 ) 52 ) is the infrared heating system, ( 53 ) is the cradle carrying the roll which holds the threads ( 31 ) to attach to the tissue ( 46 ), ( 54 ) are the coupling rollers, ( 55 ) are pressure rollers, ( 45 ) is the tissue ( 46 ) attached to the threads ( 31 ), and ( 56 ) is the rewinding machine.

The reinforced fabric obtained in this way shows the in 3 and 4 and has a weight of 628 g / m ² , a tensile strength in the direction of the warp> 1200 N / mm over the fabric width and a tensile modulus of elasticity in the direction of the warp equal to 80 kN / mm over the fabric width.

Example 3 (Application on building structure)

3a - Unreinforced beam

One Prestressed concrete beam is subjected to a three-point bending test, wherein the distance between the supports is 1,430 mm and the central one Load on the 190 mm wide side attacks. This prestressed concrete beam has the following dimensions: length 2300 mm, width 190 mm, height 160 mm, inside reinforced with 4 high quality steel bars with a diameter of 8 mm, which is arranged on the stretched side are, and with 2 bars with a diameter of 8 mm, on the compressed side are arranged.

It It is found that the first cracks at a load equal 5,000 kg and the breaking load of the beam is 8,200 kg.

3b - With tissue ( 46 ) reinforced beams

One Concrete beam as in point 3a is with 3 layers of a fabric coated, which has been prepared as in Example 1. The Application of the fabric is carried out with a two-component type epoxy resin.

The Arming, which has the dimensions of 1,180 mm × 190 mm, is on applied that side of the beam, which has a width of 190 mm, taking care that the warp threads in the Direction of the beam length arranged become.

Of the reinforced beams are subjected to a three-point bending test as in point 3a, being careful that the reinforcement is on the side attached, which is opposite to the side, the bending load is suspended.

It It is found that the first cracks in a load of 7,800 kg and the breaking load of the beam is 11,500 kg.

3c - A concrete beam as in point 3a is coated with a fabric which has been produced as in Example 2, using the coating scheme which is described in 5 as well as the patterns reported in point 3b.

The reinforcement measures 1.180 mm × 190 mm and is placed on the side of the beam brought, which has the width of 190 mm.

Of the beams reinforced in this way will perform a three-point bending test in accordance with the same Subject samples as in point 3b.

It It is found that the first cracks in a load equal to 8,500 kg and the breaking load of the beam is 11,800 kg.

Example 4 (Preparation of a fabric according to the 1D with a heat treatment carried out directly on the manufacturing loom)

A tissue containing the in 1D structure is prepared according to the patterns of Example 1, wherein a carbon thread 12K with a characteristic 800 Tex and a weft 40 Tex glass is used as a warp and the glass thread coated with a copolyamide hot melt adhesive having a melting temperature of about 140 ° C as a chain is. The amount of hot melt adhesive is such that the final denier values of the weft yarn are 100 Tex.

Of the Dornier loom Mod. HTV4 / SV has been modified in such a way that you have an infrared lamp installed on the loom to heat fabric produced before winding on the loom of the loom in one such operation, which is fully similar to which has been described in Example 1a.

In this way you get directly on the loom, a hot heat-set fabric. During weaving, the loom is programmed to achieve a weave, as in 1D is shown.

at In this weaving technique, the fabric has two sides, one from the other are different, with the one side a larger proportion of shot and the other side have a lower proportion of weft.

The fabric produced in this way is characterized by 3.8 threads / cm 12K and 800 Tex warp yarns and 1.5 100 Tex wefts, the total weight of the fabric being 320 g / m ² .

This Tissue shows a tensile strength in the direction of the warp> 600 N / mm over the Fabric width and a modulus of elasticity under tensile stress in the direction of the warp of 40 kN / mm over the Fabric width.

Example 5 (application the fabric of Example 4 on building structure)

5a - Unreinforced beam

One Concrete beam is subjected to a four-point bending test, the Distance of the supports is equal to 2,000 mm and the load on two Points is applied at a distance of 750 mm from the supports. This concrete beam has the following dimensions: length 2,300 mm, width 200 mm, height 200 mm, reinforced with a reinforcement consisting of 2 steel rods, the arranged on the stretched side, and 2 steel rods that are on the compressed Page exists.

It it is determined that the first crack, which is a dimension of 0.1 mm, occurs at a total load of 1,100 kg and the breaking load of the beam approximately 2,200 kg.

FIG. 5b shows a beam made with a layer of a fabric according to FIG 1D is reinforced

One Concrete beams as in point 5a is covered with a layer of a Coated fabric, as prepared in Example 4, Care is taken that the application is done so that the side of the fabric with a lower proportion of shot directly with the concrete surface is brought into contact.

The Reinforcement has a dimension of 2,000 mm in length and 160 mm in width and is applied to the beam in such a way that the warp threads parallel to the main direction of the beam.

The Lamination of the reinforcement is done with an epoxy resin from Two-component type.

Of the Armored beams become a 4-point bending test as in Example 5a , taking care that the reinforcement on the Side facing that side, which is exposed to the bending load.

It it is determined that the first crack, which is a dimension of 0.1 mm, occurs at a total load of 2,400 kg and the breaking load of the beam approximately 5,500 kg.

Fig. 5c - bar, which with three layers of a fabric according to 1D is reinforced

A second beam, which with three layers of tissue after 1D is reinforced according to the patterns described in Example 5b, is subjected to a bending test as in Example 5b. there shows that the load for the first crack, which has a dimension of 0.1 mm, corresponds to a load of 4,500 kg and the breaking load is 8,200 kg.

Claims (16)

Heat-treated fabric suitable for use as a reinforcing material of structures in which the warp of threads ( 11 ) consists of high modulus fibers with a modulus of elasticity under tensile stress greater than 10 GPa (gigapascal) and a tensile strength greater than 600 MPa (mega pascal), characterized in that the weft of glass fibers ( 12 ) made with a thermoadhesive polymeric material ( 22 ) having a melting temperature of 40 to 250 ° C, wherein the amount of said thermoadhesive polymeric material is in a range of 10 to 300 by weight of the glass. A fabric according to claim 1 reinforced by reinforcing threads (1) on one side thereof. 31 ) are made of high modulus fibers by means of heat-setting, which have a modulus of elasticity under tensile stress greater than 10 GPa and a tensile strength greater than 600 MPa, wherein said reinforcing threads are arranged parallel to the chain. Fabric according to claim 1, characterized in that said chain consists of a length-related Number of threads which ranges from 1 thread / cm to 12 threads / cm. Fabric according to claim 1, characterized in that said chain consists of a length-related Number of threads which consists of 2 threads / cm up to 8 threads / cm enough. Fabric according to claim 1, characterized in that said warp threads a Mark expressed in Tex (weight in g per 1,000 m thread length) which ranges from 20 Tex to 10,000 Tex. Fabric according to claim 1, characterized in that said warp threads a expressed in Tex Identification, which ranges from 40 Tex to 1,000 Tex. Fabric according to claims 1 to 6, in which the warp threads can consist of different materials. Fabric according to claim 1, characterized in that said weft threads glass threads which have a marking which is from 20 to 100 tex enough. Fabric according to claim 1, characterized in that the weft threads in different arrangements with the warp threads can be combined. Fabric according to claim 1, characterized in that the high modulus fibers from the group selected which are made of rayon fibers, high-tenacity polyester fibers, polyvinyl alcohol fibers, Polyethylene fibers, aramid fibers, carbon fibers, glass fibers and Fibers of liquid crystal polymers consists. Fabric according to claim 1, characterized in that said thermoadhesive polymer selected from the group which is made of polyolefin, polyamide, polyester and polyurethane polymers and copolymers. Method for applying the fabric according to claims 1 to 11 to the surface of building structures ( 41 ) by impregnating resins, characterized in that on the said surface successively a layer of impregnating resin ( 42 ), which according to claim 2 reinforced tissues ( 45 ), a second layer of impregnating resin ( 47 ), Tissue ( 46 ) according to any one of claims 1 to 11 and a third layer of impregnating resin ( 48 ) are applied. Method according to claim 12, characterized in that such tissue is any Arrangement of the shot with respect to the chain may have. Method according to claim 12, characterized in that on the said surface successively a layer of impregnating resin, a fabric layer and a second synthetic resin layer applied become. Method according to claim 12, characterized in that said reinforced tissue in the manner in which the side which the reinforcing fibers contains to the surface the structure of the building is directed. Use of the fabric according to claims 1 to 11 in the manufacture of composites.