BARS, AND OBTAINED BAR

The present invention refers to a process and a machine for manufacturing composite material bar, and finished bars that are especially manufactured to be used in the reinforcement of structures of reinforced concrete, for replacing the usual steel bars. Disclosure of the Invention

It is known by those skilled in the art a reinforced concrete structure wherein steel bars are used to reinforce reinforced concrete structures, strengthening same, in such a way to provide the structure with tensile strenght.

When steel is used, care must be taken to prevent the oxidation thereof, e.g., by using a minimum layer of concrete on the bar that varies according to the worksite. The more aggressive the environment conditions, such as in regions close to the sea, the thicker the layer of the concrete .

Despite such care, in aggressive or corrosive environments, the degradation of the steel bars is 85% faster than in less aggressive places. The concrete also is broken in the spot the steel oxidizes, since its volume is increased, thus breaking the concrete and generating huge expenses for the repair and maintenance of the concrete works, besides diminishing the useful life of such works significantly.

Therefore, in the 80 's studies on the use of composite material bars to replace steel bars were initiated. They were especially developed to resist and last longer in highly corrosive environments, providing an effective and valid solution to this serious problem.

They do not deteriorate and do not degrade the concrete, and are not affected by chlorine ions, acid, or high alkalinity as well. The composite material bars are made of FRP (Fiber Reinforced Polymer) fibers. Amongst the reinforcements used, GFRP (Glass Fiber Reinforced Polymer) fibers, CFRP (Carbon Fiber Reinforced Polymer) fibers, AFRP (Aramid Fiber Reinforced Polymer) fibers or BFRP (Basalt Fiber Reinforced Polymer) fibers may be cited. The fibers are bathed in a thermosetting polymeric binder, that may be made of polyester, vinyl ester and/or epoxy resins, depending on the use it is intended to, and also other types of binders.

Such bars may be used anywhere, and advantageously in worksites whose environment is aggressive to steel.

The composite material bars are capable of eliminating the corrosion problems caused by steel, and then reduce considerably the maintenance and repair costs in: cold places where large amounts of salt are used to thaw the concrete on streets, bridges, roads. Its use is also suitable when the aggregates mixed to the cement for manufacturing the concrete contain salt or other corrosive chemicals. Such applications include: parking lots; bridge covers; Jersey type porches; railings; containment walls; foundations; beams; floors and all the works that use contaminated aggregates .

The corrosion is a serious problem connected to reinforced concrete structures and is very common in: structures constructed in or next to salty water, such as, for example: wharf of ports; retention walls; dams; shore defense walls; partition walls; floating structures; canals, roads and buildings; platforms; swimming pools; aquariums; flat stones and others; in general, every concrete infrastructure that is situated in or close to salty water.

The steel is also corroded in chemicals and animals processing industries, where all types of corrosive agents are present, as well as domestic or industrial waste waters. The typical applications for such cases include: slaughter houses; plants for the treatment of waste water; petrochemical plants; pulp plants for manufacturing paper; liquid gas plants; chemical plants; piping; fossil fuel tanks; dams; cooling towers; chimneys; mining installations such as refineries; nuclear power plants; concrete containers for nuclear wastes; etc.

It is very difficult, complex and expensive to use steel bars for reinforcing concrete in places where low electric conductivity or electromagnetic transparency is required, but such difficulty is surpassed when composite material bars are used. A number of the possible applications are: aluminum and copper foundries and refineries; poles for electric lines and telephone communication. They also may be used in structures where the following are installed: electronic equipment for telecommunications and aerial navigation; airport towers; airport floors; magnetic resonance equipment in hospitals; railroad crossings; military structures requiring radar invisibility; etc.

The FRP bars are advantageously used as anchor bolts, also known as rockbolts, adding the advantage that perforations or excavations may be provided through them in non-permanent works without damaging the perforation equipment; also in tunnels or mines with acid waters or very aggressive environments to the steel therein; in mines where the extracted mineral is contaminated by the steel in its refining process.

The composite material bars may also be applied as reinforcement in: mine walls having open cuts; tunnels; peaks, slopes, etc.

The use of the composite material bars whose low density is compared to that of the steel (close to 25% of the steel weight) , is very convenient in reinforced concrete constructions where the ground cannot stand too heavy loads; remote geographic places, areas of sensitive environments and in active seismic places, that are examples of problematic places where the use of light structures in the concrete may- solve the problem.

Particularly, in South-American countries such as Chile, Peru and Brazil, the composite material bars have been used as reinforcement of polymeric concrete in cells for the electroproduction of copper in mining facilities such as: Chuquicamata, Enami, El Abra, Mantles, Mantos Verdes, Escondida, Cerro Colorado, in Chile; Ho, Milpilla, Mantos de La Luna, in Peru; Caraiba, in Brazil; also as reinforcements for ready-made concrete beams to expand dry dam No . 2 and flat stones for industrial depots of this sort, ASMAR, in Talcahuano, Chile.

Such types of bars are also used in concrete placed in aggressive environments in the United States, Canada, Belgium, Sweden, Japan, Germany, UK, China, India, Australia, and others .

Advantageously, the composite material bars have a high tensile strength that is higher than that of steel; a high resistance/weight ratio; low weight (one fourth the weight of steel) ; it provides an excellent reinforcement when the weight is important in the work, for example, for concrete pre-molded parts, besides reducing the transportation costs considerably, since four times more volume may be moved; they are not corroded; such composite materials provide chemical protection and safe mechanical resistance, throughout the whole pH range; they do not conduct electricity; they provide an excellent electric and thermal insulation; they possess an excellent fatigue resistance (CFRP, AFRP) ; they behave very well in situations involving cyclic loads; they have good impact resistance; they resist severe or unexpected loads and in specific spots; they are provided with magnetic transparency; they are not affected by electromagnetic fields; they are ideally used where there is magnetic resonance, navigation and telecommunications equipment; they are dimensionally stable to severe thermal changes; the expansion/contraction is low, what is very important when they are confined inside concrete in environments that are subject to large temperature changes; the FRP bars are an economically viable alternative to solve the corrosion problem of steel claddings.

Despite all such advantages in using composite material bars to replace steel bars in reinforced concrete structures, such bars are not homogeneous, thus restricting the use thereof.

Therefore, an object of the present invention is a process and a machine for manufacturing composite material bars that are homogeneous throughout their length and provided with helical protuberances that provide an excellent adherence to the concrete .

Advantageously, the present production process provides homogeneity and allows for a massive production, fully eliminates the humidity that is established between the fibers, before it is moistened with thermosetting resins, in such a way not to affect the adherence between the fibers and the resin that covers same.

The fiber threads of the bars are kept tensioned during the whole production time, thus making it possible to maintain the fiber threads practically parallel to one another, and all the threads that are conformed to the reinforcement of the bar are subjected to the same tension. This allows for the production of bars with better mechanical properties than the ones manufactured by the prior art processes, besides assuring a structural homogeneity along the bar.

This process provides a homogeneous and constant reinforcement/thermosetting resin ratio during the whole manufacturing process, that is, 75 to 80% reinforcement and 25 to 20% resin for GFRP, and 60 to 70% reinforcement and 30 to 40% resin for CFRP, AFRP and BFRP, thus making it possible to obtain an excellent and homogeneous tensile strength.

The bar produced by the present process comprises protuberances that are reinforced with fibers, thus providing adherence resistance between bars and concrete quite similar and still superior to that of the steel.

The bar comprises a cover made by an extrusion process that assures the full elimination of air from the external thermosetting resin and a homogeneous thickness, preferably between 0.4 and 0.6 mm, also on the already reinforced protuberances, thus assuring a perfect seal of the structural core of the bars, to protect the structural fibers against humidity and aggressive agents, said covering also being resistant to strokes.

The process provides a homogeneous and complete cure of the bars irrespective of the diameter thereof, as well as a post-cure, thus attaining the best mechanical and chemical properties of the resins. Brief description of the drawings

In order to facilitate the understanding of the present invention, schematic figures of a particular embodiment are disclosed, whose dimensions and proportions are not necessarily the actual ones, since the only purpose of the figures is to show the several aspects of the invention, whose range of protection is determined only by the scope of the attached claims.

The following accompanying figures are:

- figure 1 represents a schematic view of the machine (1) of the present invention;

- figure 2 illustrates a schematic view of the machine (1) without the cover;

- figure 3 illustrates a perspective view of the drying system (2) ; - figure 4 illustrates a partially cut view of the drying chamber (21) ;

- figure 5 illustrates a perspective view of the humidifier (3) ;

- figure 6 illustrates an exploded view of the humidifier (3) ;

- figure 7 illustrates a side view of pistons (411) and (412) that actuate the cylinders (312) e (313) of the humidifier (3) , respectively;

- figure 8 illustrates a perspective view of the driver or cold die (5) ; figure 9 illustrates a front view of the secondary humidifier (7) and the turner (6) ;

- figure 10 illustrates a perspective view of the turner ( 6) ;

- figure 11 illustrates a partially cut view of the dispenser (8) ;

- figure 12 illustrates a partially cut view of the shaper (9) ;

- figure 13 illustrates a perspective view of the tensile system (10) with the arm-bearing cars (12) ;

- figure 14 illustrates another perspective view of the tensile system (10) with the arm-bearing cars (12) ;

- figure 15 illustrates a front view of the tensile system (10) and the arm-bearing car (12) attached to a draft car (101) ;

- figure 16 illustrates a front view of the arm (121) being lifted by the piston (125);

- figure 17 illustrates a front view of the arm (121) with the clamp (127) turned towards the horizontal by the piston (126) ;

- figure 18 illustrates a perspective view of the furnace (11) ;

- figure 19 illustrates a perspective view of a traction or draft car (101) ;

- figure 20 illustrates a perspective view of the cylinder (112) of the furnace chamber (11) ;

- figure 21 illustrates an extended view of detail A of figure 20;

- figure 22 illustrates a front view of the furnace (11) and of the arm-bearing car (121) picking a bar (B) ;

- figure 23 illustrates a front view of arm-bearing car (121) placing a bar (b) in the furnace (11) ;

- figure 24 illustrates a front view of the furnace (11) and a hot air generator (117);

- figure 25 illustrates a side view of the bar (B) ;

- figure 26 illustrates a graph of the comparative tension/deformation curves of the steel bars, bars composed of graphite, carbon, aramide, glass and polyester fibers. Description of the Invention

In a first aspect, the present invention is directed to a process for manufacturing composite material bars (b) provided with protuberances (Bl), more specifically composite material bars reinforced with fibers, to be used as reinforcement for concrete and structures, comprising an assembly where the core (B2) and reinforcements of the protuberances (Bl) of composite material are formed in a process similar to but not identical to the pultrusion process, called incomplete pultrusion variant, while the cover on the core (B2) and the protuberances (Bl) is made through extrusion.

The present process comprises the steps of: a) gathering wires of fibers (f) oriented parallel to one another; b) applying tension to the grouped threads (f) ; c) bathing the grouped threads (f) in thermosetting resins, said threads (f) being kept tensioned; d) eliminating the excess thermosetting resins through compression, and regulating the resin to fiber ratio

(%); e) forming the core (B2) of the bar (b) by using a cold die (5) ; f) applying a fiber cord with helical thermosetting resins on the core (B2) as a reinforcement for the protuberances (Bl); g) starting the polymerization process of the thermosetting resin of the core (B2) and the protuberances (Bl) that are kept compressed in a linear microwave oven (14); h) applying a thermosetting resin layer at room temperature around of the core (B2) and the reinforcements of the protuberances (Bl) ; i) shaping the bar (B) ; j) starting the polymerization process of the thermosetting resin of the cover applied thereto, in a linear microwave oven (14); k) polymerizing the thermosetting resin of the core (B2) with protuberances (Bl) that are still compressed, and the cover at a controlled temperature;

1) post-curing the bars (b) , through heating for about one hour at a temperature equal to or higher than the glass transition temperature (Tg) of the thermosetting resin of the bar (B) ; m) cutting the bars (b) in the desired dimensions.

The present process comprises an aggregation and then a bath in thermosetting resins, fiber filaments, such as glass, carbon, aramide and/or basalt fibers, that are formed by very thin threads (f) of such fibers, stretched and oriented on a straight line and parallel to one another, to attain the best mechanical properties of the material.

This linear process makes it possible to obtain continuous reinforced composites materials, since the excess thermosetting resins is removed therefrom and placed parallel to one another and directed to a thermosetting resin bath that contains a catalyst, accelerators and other additives, said fiber threads being kept tensioned all the time.

The following step is the pre-formation of the core (B2) of composite material, wherein the excess resin is removed from the fibers and the fiber/resin or reinforcement/thermosetting resin ratio is controlled, preferably at a ratio of 50 up to 80% fiber and 20% up to 50% resin, similarly to the pultrusion process.

Next, the core (B2) composed of fiber and resin, at defined percentages, gets into a cold die or driver (5) to provide same with a cylindrical shape so that, distinctly from the prior art processes where hot dies are used, the present process does not require heat to shape the bar (B) .

When leaving the cold die (5) , by means of the process called incomplete pultrusion variant and without increasing the temperature of the die (5) , the core (B2) receives a fiber cord (c) moistened with resin that is helically wrapped around the core (B2) , acting as a reinforcement for the protuberances (Bl) (see figure 9) .

Next, it is transferred to a linear microwave oven (14) , wherein the polymerization of the resin of the core (B2) and the protuberances (Bl) is started; and then it is moved to a closed chamber (834) in the dispenser (8) (see figure 11) . The closed chamber (834) is located at the end of the extruder (8) , wherein the core (B2) and the helical reinforcements of the protuberances (Bl) are coated with thermosetting resins containing thixotropic material, always at room temperature. The thermosetting resins bind to the core and helical reinforcements of the protuberances (Bl) around the whole surface thereof. This thixotropic resin layer (resin having a load) , acts as a chemical protection for the fiber reinforcements of the core (B2) and protuberances (Bl) .

In the next step, with a rotating support or shaper (9) that shapes the bar (B) , the external finishing on the core (B2) and the protuberances (Bl) is carried out. Such protuberances (Bl) make it possible to sufficiently and efficiently stick the bars (B) to the concrete according to the established guidelines .

After this step, the composite material core (B2) and its cover with protuberances (Bl) leave the shaper (9) altogether and get into a second linear microwave oven (14) to initiate the polymerization of the thixotropic resin cover.

By means of a traction system (10) , the bar (B) is pulled to carry out a continuous production process. The finished bar (B), always tensioned, gets into a furnace (11) at a controlled temperature that speeds up and maximizes the polymerization process, so that the post-cure, that is a procedure for attaining the best mechanical and chemical properties of the resins, also is carried out in such a furnace (11) . The post-cure is carried out for one hour at a temperature equal to or higher than the glass transition temperature (Tg) of the resin used therefore.

Once hardened and post-cured, the bars (B) are cut in the required length, and cooled after leaving the furnace (H) -

In a preferred way, the present process comprises an initial step age of drying the fiber threads (f) before they are moistened with resin. It is carried out in a drying system (2) comprised of a fan (22) , a heater (23) and a drying chamber (21) that removes the humidity from the threads (f) (see figures 3 and 4) .

The previous drying of the threads (f) is advantageous, since it improves the adherence of the resin to the fibers, besides preventing any early deterioration of the bar (b) due to the presence of humidity.

In another aspect, the present invention is directed to a machine (1) for manufacturing bars (B) of polymers reinforced with FRP fibers, comprised of three basic portions: one for the formation of bars, another one to draft the bars, and another one for the post-cure.

In the first portion of the machine (1) , the formation of the bar (B) begins. It is where the core (B2) of the bar (b) is formed, by grouping the fibers into threads

(f), forming a beam of parallel threads (f) , where a helical reinforcement for the protuberances (Bl) is also added, plus the thermosetting resin to protect the fibers of the core

(B2) and protuberances (Bl) ; besides being the spot where the polymerization of the resin begins.

In the second portion of the machine, the core (B2) of the bar is pulled by traction or draft cars (101), assembled on a pair of chains (102) , said cars (101) being spaced 12 meters apart.

In the third portion of the machine, the cure, the post-cure and drying of the bar (b) are finished in a post- cure furnace (11) , for about one hour counting from the time the bar (b) enters the furnace to the time it exits the furnace (11) , said bar (b) being kept in the furnace in a rotational movement, at a speed of one revolution per hour. The cooling of the bars at the exit of the furnace (11) is carried out here too.

In more details, it can be seen in the accompanying figures that the first portion of the machine comprises a drying system (2) to remove the humidity of the fiber threads (f) . It is provided with a turbine type fan (22) , a heater (23) and a drying chamber (21) (see figures 3 and 4) . Preferably, such equipment is connected through stainless steel ducts, so that they do not deteriorate by the humidity drawn from the threads (f) . First, the fiber threads (f) enter the drying chamber (21) that is provided with an open circuit, and removes the humidity of the threads (f), for a better adherence of the liquid resin and mainly to prevent the deterioration of the bar (b) due to any residual humidity.1

This system functions with the air blown from the environment by a turbine type fan (22) that generates a flow of air in the system (2) .

The air is warmed by means of a heater (23) , that generates a temperature of 75 - 90°C sufficient to dry the threads (f) .

In the drying chamber (21) the humidity is evaporated due to the action of the heat, which is than dragged by the flow of air, thus drying the threads (f) . Said chamber (21) is comprised of a plurality of coils (211) through which the threads (f) pass, to assure they are dried homogeneously.

In a preferred way, the drying chamber (21) comprises a temperature controlling system (25) that is responsible for the control of the inner temperature of the room, wherein the set point that is programmed in the process is established. This system may also control the venting (24) that regulates the flow, all of which is adjusted according to the speed of the process.

The humidity may be controlled by infra-red radiation (not illustrated) and is preferably evaluated remotely and transmitted to a monitoring center by any known means .

After the threads (f) pass through the drying system (2) , they are directed to a humidifier (3) provided with a tank (31) filled with resin that is replenished with catalyzed resin (see figures 5 and 6) . The threads (f) pass through the tank (31) that contains a number of cylinders (311, 312 and 313) to direct the threads (f) towards the tank (31) in such, a way that they are impregnated with resin. ΪThe amount of resin is measured by load cells (32) that record the weight.

The tank (31) is of any suitable material for receiving resin, so that it does not to react therewith. It is supported on four small load cells (32) that are uniformly distributed that, according to the weight, indicate the resin level in the tank (31) , thus being able to determine the consumption of thread (f) per meter, and then activate the replenishing system.

After the threads (f) pass the tank (31) , they follow towards presses for removing the excess resin. Said presses are in the form of two cylinders (313) and (311) close to each other, limiting the space for passing the impregnated threads (f) through, thus removing the excess resin.

The tank (31) comprises a housing (33) (see figure 6) where two pistons (411 and 412) are attached through an inverted U-shaped structure (42) . Pistons (411) and (412) move the upper cylinders (312) and (313) upwards, respectively, so that they are approached to or moved away from the lower cylinders (311) (see figures 5, 6 and 7) .

The upper part (331) of the housing (33) is provided with hinges (330) that make it possible to pivot same in relation to the base (332) , thus allowing for eventual displacements of the tank (31) whenever required. The whole housing (33) is anchored to the machine in order to allow same to be displaced longitudinally, preferably by means of long holes (not illustrated) usually called "Chinese eyes", thus allowing the housing (33) to be moved, so that the load cells (32) , based on the weight information, may evaluate the tension required to keep the threads of the core tensioned, thus determining the tension required to act on the threads of the core and the bar (B) as a function of the weight .

The piston (411) is moved (see figure 7) , and displaces the upper cylinder (312) upwards, which is then supported by the sides of the structure (42), by means of a rolling movement (not illustrated) , until it touches the lower cylinder (311) , that turns around itself and on bearings as well. These two cylinders (311) e (312) are designed to compress and provide the required tension to the threads (f) when the bar (B) is formed.

Said piston (412) (see figure 7) moves the cylinder (313) in the direction of the cylinder (311), regulating the passage of the threads (f) impregnated with resin, and thus its amount of resin, according to a pre-established percentage, by a system similar to the one described in the previous paragraph. The amount of resin that adheres to the threads (f) is weighed and monitored by an electronic scale that informs the weight constantly, to obtain the consumption of resin per hour or a fraction thereof.

The machine also comprises a conical driver or cold die (5) (see figure 8) used to direct the threads (f) and form the core (B2) of the bar (B) , by forcing the threads (f) to join and make out the first step that corresponds to the formation of the core of the bar (B) .

To form the helical protuberance (Bl) of the bar (B), the machine comprises a turner (6) (see figures 9 and 10) that turns same at the speed set by the operator, as the core (B2) of the bar (b) passes through the center of the turner (6), according to the desired type of the bar (b) . This is carried out by means of a rotation and advancement of the core (B2) of the bar, thus attaining the required helical pitch.

The turner (6) comprises an axle (61) that supports the whole mobile assembly that is punctured by an hole with a diameter equivalent to the biggest diameter of the core of the bar (B) . The axle (61) is mounted on a set of bearings (62) and these, on their turn, on bearing blocks (64) according to the desired type and shape.

A gear (63) having a diameter and number of teeth that are determined by the transmission rate of the desired mobile assembly is assembled on the axle (61) .

A reducer (65) generates the movement according to the desired helical pitch (Bl) . The power output and the speed of the reducer (65) are regulated by the pinion (66) that connects the gear (63) of the axle (61) with the diameter and number of teeth determined in the transmission rate.

In order to change the revolution speed and the helical pitches, the reducer (65) is provided with a speed controller that increases or diminishes its revolutions.

The machine (1) comprises a twister (75) the function of which is to twist a fiber thread to form a fiber cord (c) that is the base of the helical rib (Bl) .

The core (B2) of the bar (B) passes through the hole of the axle (61) of the turner (6) ; while the cord (c) that forms the reinforcement (Bl) passes through a secondary humidifier (7) where it is moistened with resin, after having been twisted in a twister (75) , until a helical fiber cord (c) that seats around the core (B2) is formed.

The core (B2) rotates through the center of the turner (6), with the fiber cord (c) wrapped around same through the opening (67) so that the reinforcement (Bl) is formed. The forward speed and the rotation of the core (B2) are defined according to the helical pitch of the desired reinforcement (Bl) .

As specified in the structural calculation of the constructor, the diameter of the bar (B) , the heights of the reinforcements (Bl) , their angle of inclination and pitch, or distance between the reinforcements (Bl) , are defined. The secondary humidifier (7) is formed by a tank containing resin (71) , to moisten the fiber thread (f) that is the base of the reinforcement of the helical protuberances (Bl) on the core (B2) . Said secondary humidifier (7) comprises cylinders (72, 73 and 74) that direct the fiber cord (c) into the tank (71) , humidifying same, and the cylinders (73) and (74) remove the excess resin when the cord (c) passes there between.

The machine (1) comprises a linear microwave oven (14) , wherein the core (B2) with the cord already moistened with resin is disposed, in order to start the polymerization process of the resin that is both in the core and the fiber cord around the core (B2) . In a preferred way, use is made of a linear microwave oven (14) that allows for the beginning of the homogeneous polymerization of the resin, especially as large diameter bars .

The machine (1) further comprises a dispenser (8) (see figure 11) that adds a thermosetting resin cover plus thixotropic material prepared with a catalyst to the core (B2) and the reinforcements of the protuberances (Bl), thus forming a cylindrical bar (b) to be shaped.

The dispenser (8) comprises an axle (81) connected to an endless screw, forming a moving part. The endless axle assembly has a hole so that the core of the bar (B) may pass therethrough. The axle (81) is assembled on a set of bearings and these, in turn, on bearing blocks (811) .

A gear (82) having a diameter and number of teeth according to the desired advance is coupled to the axle (81) .

The endless axle (81) is the mechanism that delivers the prepared resin and adds the amount of substance required for forming the bar (B) .

The course of the helical means (812) , plus the rotation, displaces the resin and compresses towards the cylinder (831), followed by the conical pipe (832) of the dispenser (8) that diminishes its diameter towards a cylinder (833) that has the same diameter as that of the bar (B) . This cylindrical part (833) may be changed according to the diameter of desired bar (B) .

The reducer (not illustrated) generates motion so that the displacement of the endless axle (81) moves the resin and compresses same between the cylindrical delivering end (833) and the core (B2) . Every revolution of the endless axle (81) injects a mass of pre-defined mixture around the core of the bar (B) . The synchronization is established so that the dosage is consistent with the production pace. The power and speed of the reducer are transmitted to a pinion (not illustrated) that couples the gear (82) of the endless axle (81) , so that the diameter and number of teeth may be determined according to the transmission. In order to change the rotation speed and change the dosage of the mixture in the core (B2) , the reducer is provided with a speed controller that increases or diminishes its revolutions.

The dispenser (8) also comprises a feeder (85) that supplies raw material continuously, thus generating the pressure required to operate regularly. The feeder (85) is provided with a mechanism that makes it possible to draw the undesirable air that is introduced in the process. It comprises an engine (851) that drives an endless screw (852) that conveys raw material to the dispenser (8) .

The speed of the feeder (85) is controlled by a speed controller (not illustrated) that makes it possible to change the rotation of the engine (851), feeding the dispenser (8) according to the need required in the production. The endless screw (852) is connected to an axle, both making out a moving single part.

To connect the axle of the engine (851) to the axle of the endless screw (852), use is made of a joint (853), preferably made of rubber having iron supports so that the torque of the starting may be absorbed.

The screw/endless axle assembly (812) has a hole in the middle thereof so that the bar (b) may pass through same. The axle is assembled on a set of bearings and these, in turn, on bearing blocks (811) .

A shaper (9) (see figure 12) turns around the core (B2) of the bar (Bl), thus forming same. It turns at the same speed and direction than those of the turner (6), thus shaping the helical pitch on the spiral pitch made by its engine (not illustrated) .

The shaper (9) comprises shaping discs (91) that compress the bar (B) , thus providing a uniform distribution of the material. The shape of the shaping discs (91) varies according to the type of the bar (b) that is to be manufactured.

An axle (92) couples the shaping mechanism, thus making out a moving single part. The mold of the bar is disposed inside the axle (92) thus being molded and assuming the characteristics of a screw as it is rotated, completing the finishing of the bar (B) . The axle (92) is assembled on a set of bearings and these, in turn, on bearing blocks (93) .

An axle (92) couples a gear having a certain diameter and number of teeth according to the desired advance .

The reducer generates the motion of the shaper (9) synchronized with the pitch of the turner (6), said two systems operating at the same speed. The diameter and number of teeth of the gear of said reducer are determined by the transmission relationship. To change the rotation speed and the synchronization, a speed controller that increases or diminishes its revolutions is incorporated to the engine.

The machine comprises a linear microwave oven (14) , the core (B2) having the cord already moistened with resin passing therethrough, and having the thixotropic resin cover already shaped, the purpose of said furnace being to start the process of polymerization of the thixotropic resin fthat it is around the core (B2) and on the fiber cord around the core that provides the helical reinforcement of the protuberances (Bl) . The microwave oven is the most preferred, since it makes it possible to start the homogeneous polymerization of the resin with thixotropic agent, especially as large diameter bars.

In the second portion of the machine, the bar (b) already provided with resin is kept tensioned by a traction system (10) provided with three traction or draft cars (101) , spaced 12 meters apart, so that two cars (101) pull a length of bar (B) therebetween equivalent to a piece of bar (B) of approximately 12 meters. The system is pulled by double chains (102) 36 meters long each, coupled to the motor driving system by crowns (103) having a diameter of about 0.822 meter.

The traction system (10) composed by traction cars (101) attached to chains (102) through guides and crowns (103) is supported by a double T steel profile structure (105) anchored to the floor.

The chains (102) are pulled by brackets, bearing block supports and bearing case of the axles of toothed wheels (104) .

A reducer (not illustrated) of the stretcher (10) establishes the production speed of the machine (1) , thus maintaining same directly synchronized with the whole manufacturing assembly. The diameter and number of teeth gear of the reducer are defined according to the transmission.

To change the production pace of the machine (1) , a speed controller is incorporated (not illustrated) , that increases or diminishes the rotations of the engine of the stretcher (10) .

The chains (102) are kept stretched between two crowns (103) and supported by the structure (105) (see figures 13 and 14) . Guides (105) are provided between the crowns (103) . Thus _/ the system comprises two chain sets (102) and four guides (not illustrated) in the cars (101) that operate parallel and consecutively at the same speed, drafting the three cars (101) of the traction system (10) .

The draft car (101) is the traction mechanism of the machine (1) that is displaced between the crowns (103) that drive the chains (102) of the system. The operation wherein the bar (b) is picked by the car (101) is carried out by jaws (106) • The function of the compression of the bar (b) is to hold same in the upper transverse jaw holder (106) in the car (101); this mechanism runs along 12.1 meters while the bar (b) is being manufactured. After the specified length is attained, the bar (b) is picked by mechanical pneumatic arms (121) , so that the bars (B) are tensioned all the way, and then it is cut and removed from the axle of the machine

(I) for manufacturing bars (B) , to be conveyed to the furnace

(II) already in the third portion of the machine.

There are two arm-bearing cars (12) (see figures 13 and 14) disposed at the ends of the structure (105) of the traction system (10) . They are installed on four guides (128) per car (12) that run at the same speed established for the production, and attached to the draft car (101) for cutting the bar (B) .

The arm-bearing car (12) is coupled to the draft car (101) through a pneumatic piston (122), that is perpendicular to the arm-bearing car (12) and actuated by a sensor (not illustrated) , coupling them in a precise position. Once the bar (B) is cut, the pneumatic pistons (122) are released, releasing the two cars (12) from the draft car (101) . Next, the two pistons (125) that are installed at one of the ends of the arm-bearing car (12) are operated, to convey the bar (B) to the furnace (11) . Once the bar (b) is released from the mechanical arms, the pistons (125) return the arm-bearing car (12) to its starting point.

The mechanical arms (121) are transfer mechanisms that go from the traction system (10) to the furnace (11) . The mechanism thereof is pneumatic and provided with four pistons, a first piston (123) actuating a clamp (127) that catches the bar (B) ; the second piston (125) raising the arm (121) with the bar (B) (see figure 16), removing same from the production axle; the third piston (126) rotating the clamp (127) from a vertical position to a horizontal position (see figure 17) , and directing same to position the bar (B) in the furnace (11) ; and the fourth piston (124) finally- pushing the bar (b) towards the furnace (11) . The whole operation of the arm (121) is carried out without stopping the traction system (10) , thus preventing stops or intermittences in the manufacturing process that generate quality issues in the finished product. The mechanical arms (121) are supported on the arm-bearing cars (12) by supports located at the ends of each arm, thus assuring an effective operation thereof.

The machine (1) also comprises a cutting system (129) for the bars (B) as a small tool (see figure 16) installed in one of the mechanical arms (121) that support the bar, cutting the bar (b) in the specified length. Said cutting tool (129) is provided with a very hard disc that rotates at high speeds. In a preferred way, said tool is automatic and its mechanism is pneumatic.

The third portion of the machine is the furnace (11) whose shape is cylindrical, as illustrated in figure 18, and comprises a concentric disc (111) that rotates the axle of the cylinder (112) in the inner chamber of the furnace (11) that is supported by bars (113) . The housing (110) is fixed and supported on the floor independently of the disc (111) . The housing (110) comprises six mixing fans (114) that turn the temperature of the furnace (11) homogeneous, which temperature is monitored by sensors (not illustrated) that electronically keep the temperature constant required for the post-cure of the material.

In a preferred way, the heating system is run through hot air generators (117) (see figure 24) .

The entrance or exit of hot air is controlled by relevant pneumatic valves (not illustrated) that modulate the flow of thermal fluid according to the temperature requirement .

The housing (110) is provided with an insulating cover that prevents heat from venting to the environment .

The fans (114) are the means used to homogenize the temperature of the furnace (11) . These six designed equipment are disposed in such a way that they assure a constant temperature in the furnace (11) .

The temperature control system is monitored by thermocouples (not illustrated) disposed on different points in the furnace (11) , and thus they monitor the temperature in different points. This information is received by the control system where it is processed. The control mechanism commands the thermal fluid valves to open, close or maintain its unchanged state, according to the need. The control valves act proportionally, thus varying the opening between such points from 0% to 100%.

The bars (B) are disposed inside the furnace (11) by the arms (121) that convey same, thus going through the window (162) of the housing (110) to be positioned in the cylinder (112) of the chamber of the furnace (11) . The bars are disposed in recesses (161) of peripheral crowns (16) of the cylinder (112) and held by jaws (118) that provide a mechanical action on a displacement guide inside the cylinder (112) of the chamber that commands the jaws (118) to open or close. In a preferred way, the displacement of the bar (b) should not be higher than 6 centimeters, the maximum gap between the bars (B) .

Once a 360 degrees turn of the cylinder (112) inside the furnace (11) is completed, the bar (b) is cut on each end to a specified length by a tool (not illustrated) installed in a parallel system that is operated by a sensor whenever it detects the bar (B) . Said cutting tool is provided with a very hard disc rotating at high speeds that is automatically operated and the mechanism of which is pneumatic. When the bar (b) is cut, the residues left in the jaw are released and eliminated, being ready again to receive the next bar (B) .

The support of the rotor is composed of a concentric axle that runs along the whole rotor and rests on supports and/or bearings (115) that are supported on a structure (116) , thus keeping the moving elements raised.

The heating of the furnace (11) may be accomplished by any means known in the art, such as steam, oil, electricity or gas .

When electricity is used to heat same, for example, electric resistances disposed in air inlets may be used, thus heating the furnace (11) according to a temperature required to post-cure the bar (B) .

This temperature is homogenized with temperature controllers and fans. The first hot airflow gets into the exit of the bar (B) of the furnace (11), counter-currently along the length of the bar (B) , and the second air inflow is in the center of the furnace (11) , also in a counter-current way.

The air outflow is almost at the entrance of the bars (B) at the other end of the furnace in a collector that flares towards the hot air outflow chimney (119) (see figure 24) together with the gases that are expelled by the cure, said gases being retained in an activated coal filter so that they are not vented to the atmosphere .

When gas is used to heat same, for example, two gas burners (not illustrated) disposed on the airflow inlets may ^¬ be used, thus heating the air with direct flame, baffles and flame keeper, so that the hot combustion gases may run counter-current through the furnace (11) at the temperature that is required to cure the bar (B) .

The engine and reducer system of the furnace (11) has a final maximum speed of one revolution per hour, that is the time the cure process lasts. The diameter and number of teeth of the pinion of the reducer that acts together with the gear of the disc axle are determined by the transmission relationship.

At the exit of the furnace (11) the bars (B) are cooled by means of cold air, so that the bars (B) may be handled quickly and pass on to the next quality control step by means of electronics, radii and mechanic means.

In a preferred way, the present machine comprises a coil holder (13) that, as illustrated in figures 1 and 2, is a rack made from profiles with several shelves where several fiber thread (f) coils that are used for manufacturing the core of the bar are disposed. Said rack is provided with four wheels (131) so that it may be moved easily. The number of coil racks to be used varies according to the need of the production, so that as many as needed are used in order not to lack fiber to feed the machine (1) with raw material.

The threads (f) of a coil rack (13) are joined to those of the next rack (13) , so that the production of bars (B) may be kept continuous without the need to stop same to feed more raw material .

The lack of raw material makes the machine (1) stop immediately, thus preventing failures in the production caused by cores (B2) that do not comply with the specifications .

Said machine (1) manufactures FRP bars and is provided with pneumatic, hydraulic, mechanic, electronic and electric devices. Its maximum production capacity is 200 bars per hour, at a linear speed of 2,400 meters per hour, with a 100% operational efficiency. It operates automatically, with temperature, pressure, speed and the like set points.

The present machine (1) also comprises a support (15) for finished bars (B), provided with a plurality of semicircular lugs (151) for receiving and accommodating the already cured bars (B) , when they leave the furnace (11) . The bars (B) are released from the furnace (11) when the jaws (118) are opened, and then go out through the window (162) of the housing (110), and are then deposited on the lugs (151) until they cool down.

The invention also is related to bars (B) produced in the present machine by the process called incomplete pultrusion and extrusion variant, made from a composite material .

The main characteristics of this bar are: a ϊhigh corrosion resistance irrespective of the environment, thus turning same stainless and durable; an excellent mechanical resistance, and a resistance to breaking loads higher than that of steel; an elasticity modulus that varies according to the fibers used; a deformation level higher than that of steel; great tenacity and rigidity; a weight that is one fourth the weight of steel; a thermal expansion coefficient very close to that of steel and concrete; it does not conduct electricity; and does not create magnetic fields, since it is not metallic.

The bars (B) made of composite material are a combination of two or more different materials that have a inter-phase that may be perceived therebetween.

In the present case, they are polymeric materials comprised of a thermosetting resin and a fiber reinforcement.

Among the thermosetting resins that may be cited, but not limited thereto, we have polyester, vinyl ester, epoxy resins, or combinations thereof.

As to the reinforcement materials, any material chosen among, but not limited thereto, glass, carbon, aramide, basalt fiber, the combinations thereof or any other reinforcement fiber may be used.

Such FRP bars (B) (polymers reinforced with fibers) may be used as reinforcement for the concrete.

Since the main characteristics of the bars (B) are their high mechanical resistance and excellent chemical resistance, they may be used to reinforce concrete in a safe, resistant, durable way in very aggressive environments. The traditional steel reinforcements have not managed to solve the corrosion problem, generating huge repair and maintenance costs due to the degradation thereof. The composite materials solve this serious problem, since they increase the useful life of concrete considerably by not presenting any problem in any type of corrosive environment.

Another feature of such bars is that they are manufactured by means of a process that has been specifically developed to generate composite material bars provided with protuberances .

Resistance tests using steel bars and composite material bars manufactured by the present process have been conducted, the results of which are shown in the table below and figure 26. As can be seen, the composite material bars are superior to steel bars.

The mechanical properties of the composite material bars to reinforce concrete are superior to those of steel due to the orientation of the fibers, the fiber/thermosetting resin ratio, protuberances (Bl) to increase the adherence to the concrete, and mechanical and chemical properties of the polymeric binder.

The table below shows a comparison between the steel cladding, steel cord and composite material cords.