CN1190302C - Method for producing in continuous installation a compacted rolled concrete composition reinforced with fibres, and continuous installation therefor - Google Patents

Abstract

The manufacturing process for reinforced concrete includes supplying a vibrating dosing machine with pre-pasted metal fibres. The fibres and a hydraulic binding agent are added at a fixed proportion, prior to the addition of mixing water to achieve an output with between 90 and 150 liters of water per cubic meter of dry constituents. The process for continuous manufacture of reinforced concrete includes supplying a vibrating dosing machine with plates of pre-pasted metal fibres in order to deliver them to a conveyor. The fibres are delivered at a proportion of between 25 and 60kg of fibre per cubic meter of dry concrete constituents prior to the fibre addition. A hydraulic binding agent is then added to the mixture in the proportion of between 180 and 400 kg per cubic meter of dry concrete constituents. The proportion of mixing water is then determined in order to ensure that the mixer delivers a constant output with a proportion of water between 90 and 150 liters per cubic meter of dry constituents.

Description

Method for producing compacted concrete compositions reinforced with metal fibers in a continuous plant and continuous plant for carrying out the method

technical field

The invention relates to a method of manufacturing a compacted concrete composition reinforced with metal fibers in a continuous plant, as well as to a continuous plant and a continuous fiber batcher for carrying out the manufacturing method. The fiber-reinforced compacted concrete composition obtained by carrying out the method can be used to lay continuous road pavements or industrial sites without joints.

Background technique

For laying a solid poured concrete road surface without joints, a method known as the continuous reinforced concrete method is known, in which steel bars typically having a diameter of 16 mm are continuously connected to each other over the entire length of the road. Once the steel bars are laid, the concrete is typically poured using a slip formwork machine. However, continuous reinforced concrete is a technique that is heavy to use and comes at a high cost.

Conventional vibrated or poured concrete can be used to manufacture seamless industrial slabs of up to 2,000 square meters in size (often protected and therefore less resistant to weather and temperature changes than roads) after being reinforced with steel fibers, fiber The properties of the seams leave gaps. On the contrary, these concretes have not heretofore been effectively used to lay continuous, jointless highway pavements, despite such applications being noted. In fact, the higher cement and water distribution produces hydraulic shrinkage in these concretes in addition to thermal shrinkage. Mechanical stresses are such that fibers cannot control them. Consequently, the shrinkage phenomenon of concrete causes significantly larger cracks than paving slabs, often with crack openings of several millimeters. Therefore, it is necessary to leave joints on the road pavement to localize the shrinkage and reduce cracking, which is detrimental to the economic superiority of a continuous road pavement and greatly restricts the development of vibrated or poured fiber concrete road pavements.

Compacted concrete compositions differ from conventional poured or vibrated concrete in that, for similar or superior mechanical properties, reduced hydraulic binder ingredients and reduced water content are necessary. In the above two conventional concretes it is known to insert metal fibers. The reduced binder mix and water content give compacted concrete the advantage of less hydraulic shrinkage and therefore less noticeable crack formation: as long as fibers with very good anchors are used in the concrete matrix, as long as With the correct addition of these fibers when making concrete, it is possible to lay continuous highway pavements with compacted concrete reinforced with metal fibers. Compacted concrete has less water content and can also achieve sufficient bearing capacity to use road machinery to spread the material (to complete the paving of the asphalt cover), which is then compacted with a vibratory or pneumatic compactor, and finally , delivered without delay. Conversely, the consistency of poured concrete requires the use of sliding facing machines or vibrating machines by conventional techniques and is delivered to service after a period of sufficient setting, typically 7 days.

The metal fibers used in industrial decking panels are often drawn fibers, typically having filaments with a diameter of 1 mm. The types of effective anchorage of existing fibers in the concrete matrix differ from each other.

In order to solve the problem of fibers agglomerating into balls, some fiber manufacturers are focusing on the geometric shape and surface style of fibers, which can be used directly after leaving the factory without additional processing. On the contrary, laboratory tests and field experience have shown that these fibers are not the best performing on the market, at least in terms of mechanical properties and crack control of concrete plus metal fiber composites.

It is known that French patent 2225392 proposes a method for adding metal fillers for reinforcement to a concrete, these metal fillers are composed of clusters of metallic material composed of a A binder is bonded by adding the mass of metallic material to the composition which itself constitutes the concrete, then stirring to form a fine distribution visible to the naked eye, followed by dissolving the binder and continuing to mix the compound matter, so that it forms a good distribution visible to the naked eye. In effect, pre-glued fibers are added to the concrete in the form of a slab. Agitation in two distinct steps, either for 15+ minutes along the line mounted on a car called a mixer, or for about 1 minute in the unit's agitator.

It should therefore be noted that, prior to the present invention, the production of fiber-reinforced poured or extruded concrete with pre-glue in plate form was always carried out on discontinuous plants or on mixer trucks. The fibers are added manually or by a special machine either directly into the mixer of the equipment, or into a mixer truck. The disadvantage of using a mixer truck is that the mixing quality is not ideal and the fiber distribution is not uniform. Placing bagged fibers manually on the feed belt or directly into the mixer has the drawback of incorrect dosing and inefficiency. Efficiency can be improved by using specialized machinery, but the problem is that simple machinery can add at most the amount of fiber required to make each one-mix mortar into the mixer of a continuous plant. It should be noted that poured or extruded concrete reinforced with fibres, is typically used in areas such as industrial decking, often by hand, or in civil engineering projects such as pilings. Site-fed materials require relatively low production efficiencies and are suitable for manufacturing on discontinuous equipment.

On the contrary, road works are mechanized works requiring highly efficient machinery. The demands of these sites for hydraulically binder-treated materials and concrete for roads (for example, for continuous reinforced concrete sites or compacted concrete sites) require equipment with an hourly output significantly higher than that of conventional discontinuous equipment. degree. The disadvantage of discontinuous equipment is that in the production cycle, the first process is to send various materials to the mixer, and then the mixer stirs to mix these materials, and finally, the mixer mixes the mixed materials. Dumping on transport truck. Thus, another plant can be run without the agitator having to be shut down for each material loading cycle. This type of equipment is called "continuous equipment" because the mixer is always fed by a conveyor belt on which the required quantity of aggregate and hydraulic binder is loaded. During the concrete manufacturing process, the mixer only However, the stop is only during unloading of transport trucks. Therefore, the production efficiency of continuous equipment is significantly higher than that of most discontinuous equipment. Continuous equipment is well suited for road work because continuous equipment is easier to move from one job site to another than discontinuous equipment. Therefore, continuous equipment is called "mobile equipment" or even "hypermobile equipment" (that is, in this case, it can be handled by only two tractor vehicles).

French patent 2633922 proposes a method for the manufacture of compacted concrete reinforced by fibers, according to which method 7 to 15% of cement or road binder, 4 to 7% by weight of Water and 0.8 to 4% (weight) of metal fibers, these materials are added by a special batcher, and other materials are basically composed of crushed stones of 0 to 31.3 mm. However, this document does not mention this special batcher at all, nor does it mention the mode in which the fibers are added from the batcher to the agitator.

French patent 2654830 proposes a continuous batching device for adding fibers to road, bridge and tunnel engineering building materials. However, a problem with this arrangement is that the fibers form balls or burrs in the fiber distribution device that feeds towards the conveying device for the fibre-reinforced material. According to this document, the oscillating trough of the distribution device is connected to a fiber separation device, such as a toothed rotor, a charge air nozzle or a reciprocating rake, in order to break up the fiber burrs. However, all these separation devices are not sufficiently described or shown in this document to be effectively used by the proprietor.

The correct addition of metal fibers with continuous equipment is more difficult than with discontinuous equipment: the desired amount of fiber must be incorporated into the concrete with the desired precision, while avoiding the problem of fiber agglomeration into balls.

Contents of the invention

The present invention aims at proposing an ideal solution to these hitherto unresolved difficulties, in particular the feeding of pre-glued metal fiber sheets. The method of the invention proposes a continuous plant manufacturing method of fiber reinforced compacted concrete which effectively avoids or at least maximally limits the aggregation of fibers into balls during the production stage of fiber reinforced compacted concrete. Another object is to avoid and limit the aggregation of fibers into balls during the transport and use phases of the fiber-reinforced compacted concrete. Finally, the invention also aims to avoid the formation of these balls. The purpose of the inventive method is also to:

- the incorporation of fibers into the manufactured compacted concrete, starting from pre-glued plank fibers, with a high efficiency compatible with the output of continuous equipment used in highly mechanized road construction sites;

- to dissolve the glue that binds the plank fibers into the most released fibers for their individual flexural strengthening and to control crack formation in the compacted concrete used on the job site; another purpose is to release in the concrete all the prepackaged fibers fibers of glued boards; and

- The use of these fibers enables immediate extraction of the desired composition at any point in the manufacture of fiber concrete, the resulting dosing accuracy is -5% to +10% of the required standard dosing value, which is essential to guarantee the concrete used on the site Proper properties and uniformity of the fibered composition are important.

To this end, the present invention aims at proposing a method for the manufacture of fiber-reinforced compacted concrete compositions on a continuous plant, which method comprises the following steps:

(1) Continuously supply a variety of pellets conveyed on one conveyor belt,

(2) continuously feeding metal fibers from a vibrating batcher onto said conveyor belt,

(3) Continuously supply the aggregates and fibers conveyed by the conveyor belt, a hydraulic binder and mixing water to a mixer, which may include one or more additives for concrete,

It is characterized by:

The step (2) is to supply the vibrating batcher with pre-coated metal fiber sheets, so that the fiber sheets and/or the degummed fibers are transported to the conveyor belt in the step (1), and the fibers are Fiber-free concrete dry material is supplied at a ratio of 25 to 60 kg of fibers;

Step (3) is to supply the hydraulic binder at a ratio of 180 to 400 kilograms per cubic meter of fiber-free concrete dry material, and the ratio of stirring water is determined to be a continuous supply of a mixer with a water content of per cubic meter of fiber-free concrete dry material. Fiber-reinforced concrete composition fed 90 to 150 liters of water. By supplying pre-coated slab-like fibers, the number of fiberballs and large fiberballs in concrete compositions can be eliminated or reduced. Therefore, the fibreboard pre-soaked in the solvent is degummed under the combined action of strong shear stress generated by the agitator and water added at the agitator blades.

Fiber-reinforced compacted concrete is best transported by dump trucks rather than mixer trucks, and it is better to spread the concrete on roads with a leveler to maintain the good properties of fiber-reinforced concrete compositions.

In the method of the present invention, in the step (1), a solvent, such as water, is supplied to the conveyor belt for dissolving the glue that keeps the fiber into a board, and the solvent is at the drop point or drop point of the fiber supplied by the batcher. Supply to the conveyor belt near the point.

According to one embodiment, the batcher comprises at least one vibrating batching container and one vibrating tank or one weighing conveyor belt in sequence. For example, the method of the present invention is to supply the solvent to the vibrating tank, make the fiber at least partially soak in the vibrating tank whose bottom is filled with solvent, and supply the solvent together with the vibrating tank from the vibrating tank to the conveyor belt.

According to other embodiments, the method of the invention is to spray the solvent onto the conveyor belt with at least one nozzle located downstream of the fiber landing point.

The method of the present invention provides fiber incorporation into various pellet materials by feeding fibers onto the conveyor belt after the first pellet is fed and before the last pellet is fed.

According to other features of the present invention, the method of the present invention calculates the proportion of stirring water supplied to the agitator in the step (3) according to the inherent water content of each granular material supplied in the step (1).

In one embodiment, the method of the present invention is that in step (1) supply the full-scale aggregate of 83 to 93% (weight) of fiber-free concrete dry material, and in step (3) use 7 to 17% of fiber-free concrete dry material A cement or a hydraulic binder is supplied in the proportion of % (weight), wherein 0.3 to 1.8% (weight) of the hydraulic binder consists of a concrete setting delay additive added to the mixing water and/or The plasticizer is formed to lubricate the contact between particles and delay the setting of concrete.

The present invention also aims to propose a continuous plant implementing the aforementioned method, which comprises:

- a series of hoppers arranged at intervals on a motorized conveyor belt, each hopper adapted to deliver a type of pellet to the conveyor belt, each hopper associated with a weight for determining the quantity of pellets conveyed by said hopper or a volumetric device connected,

- a vibratory batcher suitable for feeding the metal fibers onto the conveyor belt, said batcher being connected to a gravimetric device for determining the quantity of fibers delivered,

- one or more containers of hydraulic binder, each container dispensing a hydraulic binder, each container being connected to a gravimetric or volumetric device for determining the quantity of the dispensed binder , another container can be used to dispense a supplementary powder such as fly ash,

- a stirring water feeder connected to a stirring water volume regulator,

- an agitator comprising a network of nozzles for injecting stirring water into the mixing chamber, said network of nozzles being supplied with agitating water via said water volume regulator, the hydraulic binder being delivered from said container to the agitator The inlet of the fiber and aggregate composition is sent by the conveyor belt to the mixer for the mixing of all the compositions of the compacted concrete reinforced by fibers,

The apparatus is characterized in that it comprises a solvent feeder to deliver a solvent to the conveyor belt at or near the outlet of the vibrating batcher, said solvent serving to dissolve the glue of the fibreboard, thereby releasing the glue produced by said batcher. Pre-coated metal fibers of the board delivered with the machine. Said solvent feeder is advantageously arranged to deliver solvent downstream of the first pellet feed hopper and upstream of the last pellet feed hopper.

In one embodiment, the vibrating batcher includes a first vibrating container, the first vibrating container has a helical slope on its cylindrical inner wall, and the fiberboard is suitable for vibrating movement from the bottom of the container towards the top on this helical slope, so Said helical slope is extended at its top by an intermediate groove leading to the top of a second vibrating vessel which also has a helical slope on its cylindrical inner wall, and the fiberboard is suitable for use on this helical slope The upper part moves from the bottom of the second vibrating container towards the top, the spiral slope of the second vibrating container leads to a vibrating trough, which sends the fibers to the conveyor belt, and the solvent supply includes at least one Nozzle above the upstream end of the vibrating trough.

The advantage of having two vibrating vessels in series is to eliminate the asymmetry of feeding and distributing fibers from a single primary vibrating vessel, which is fed in a discontinuous manner by a lift trolley that is regularly filled with fibreboard from a ladle.

The first vibrating vessel advantageously includes an articulated arm interposed between the top of the helical ramp and the central trough, said articulated arm being adapted to block access to the central trough in a closed position, returning fibers to the center of the first vibrating vessel and bottom, while a controlled amount of fibers is passed towards said intermediate channel in a variable open position.

According to other characteristics, said intermediate trough comprises vibrating fingers parallel, substantially in a vertical plane, fixed at their upstream end and free at their downstream end, in order to be able to separate the stacked fibreboards, in the supply of fibreboards to the second container A relatively uniform distribution is obtained, the longitudinal extension of the fingers being parallel to the direction of movement of the fiberboard.

In one embodiment, the second vibrating container is provided with a height detector for detecting the height of the fibers in the second vibrating container, said detector being connected to a control motor of the articulated arm so that when the second vibrating container The arm is moved towards its closed position or towards its open position when the number of fibers in the arm exceeds or falls short of a predetermined limit.

According to other features, the second container is equipped with a frequency modulator to vary its vibration and its fiber supply, said modulator being controllable by a scale for the amount of fiber supplied at the outlet of the second container. In fact, the second container can be mounted on a scale and the supply of fibers fixed by the central control of the dispenser in the control room of the plant. The equipment operator can input the ideal fiber supply amount on the digital controller, and then the equipment of the present invention operates automatically to control the frequency modulator. Therefore, fiber supply can be checked by chart recorder and print editor.

The apparatus of the present invention is advantageously equipped with a central control unit, which is connected with various weight or volume detectors of hoppers, containers and batchers, and a water volume regulator of the stirring water supply, so that according to the water content , the feed amount of each pellet and/or the feed amount of solvent to calculate and control the amount of water fed into the mixer.

According to other features, each hopper and each container leads to a weighing conveyor belt driven by its own drive motor, the speed of which can be controlled by the central control unit according to the weighed weight, so as to control each type of concrete. supply of materials.

Description of drawings

Other aspects, features and advantages of the invention will be better understood with reference to the attached drawings and non-limiting examples.

The accompanying drawings are as follows:

Fig. 1 is the schematic diagram of whole set of continuous equipment of the present invention;

Fig. 2 is a partially enlarged schematic view of a hopper connected to a weighing machine conveyor belt;

Fig. 3 is a perspective view of a fiberboard that can be used in the method of the present invention;

Fig. 4 is a schematic side view of a vibrating batcher for equipment of the present invention;

Fig. 5 is a schematic top view along the V-V line in Fig. 4 in the open position of the hinged arm;

Figure 6 is a view similar to Figure 5, showing a partial view of the articulated arm in a closed position;

Figure 7 is a partially enlarged view of the stirrer shown in Figure 1;

Fig. 8 is a sectional view along line VIII-VIII in Fig. 7;

Fig. 9 shows a screen page displayed on the terminal of the central control device shown in Fig. 1 .

Detailed ways

Figure 1 shows a complete continuous plant for the production of fiber-reinforced compacted concrete.

This device comprises a first hopper 1 shown in FIG. 2, for example for containing and distributing crushed stones, and a first scale 2 whose frame is substantially hinged at a point 3 at the lower end of the hopper 1 . The frame of the scale 2 supports an endless conveyor belt 4 driven by a drive motor 7 which drives the rollers 5 to rotate through a chain 6 , the drive shaft being fixed at one end of the frame of the scale 2 with respect to the hinge 3 . The other end of the scale 2 is connected to a strain gauge 8 suspended on the equipment frame B which also supports the first hopper 1 . As shown by the arrow F1, the gravel in the first hopper 1 falls on the weighing conveyor belt 4, and the weighing conveyor belt 4 is driven to rotate counterclockwise in the direction of the arrow F2, so that the gravel is on the left end of the weighing conveyor belt as shown by the arrow F3 Falls on the conveyor belt 9 below. The strain gauges are connected via a cable 10 to a central control unit U, as shown in FIG. 1 . Obviously, the first conveyor belt 9 is also electric, and its motor and the above-mentioned motor 7 can be controlled by the central control device U.

The second hopper 11 is located near the first hopper 1 and also has a scale 12 at its lower end, the support of which is configured upside down with the support of the first scale 2 . In fact, its motor 17 is located at the left end of the support, and the strain gauge 18 is fixed at its right end. The weighing conveyor belt of the second scale 12 is driven clockwise on FIG. On the conveyor belt 9, cover the previously fallen pellets. Obviously, the conveyor belt 9 is driven counterclockwise on FIG. 1 . The strain gauge 18 is also suspended on the frame B and is connected to the central control unit U by a line 20 .

The first conveyor belt 9 unloads all the two kinds of raw material aggregates on an electric second conveyor belt 19, as shown in Figure 1 . The other two hoppers 21 and 31 are located above the second conveyer belt 19, the third hopper 21 is used for distributing the third kind of granular material that constitutes the concrete, and the fourth hopper 31 may not be used in the embodiment of the present invention. Obviously, the number of hoppers can vary, for example six hoppers can be configured to hold different types of aggregates for different types of concrete. As with the other hoppers, each hopper 21 and 31 is connected to a scale 22,32, each scale being connected to its own motor 27,37 and its own strain gauge 28,38. Each strain gauge and each motor can be connected to the central control unit U via lines 30 and 40 .

As shown in Figures 1 and 4, the apparatus of the present invention also includes a batcher D, and the batcher D is equipped with a vibrating tank 41, and the outlet end of the vibrating tank 41 leads to a third hopper 21 upstream located at the second conveyor belt 19 top. Injection port 42 .

Distributor D is equipped with a lifting container 43, and lifting container 43 has guide wheel 43a in vertical guide groove 44 at its lower end, has guide guide wheel 43b in vertical guide groove 45 at its upper end, the top of guide groove 45 It is horizontally curved so that the lifting container 43 at a high position is dumped, as shown in FIGS. 1 and 4 . Lifting container 43 is used to load bales (the weight of which is for example 1100 kg) of pre-glued fibreboard P, for example of the type shown in FIG. 3 . For example, these fibreboards are unloaded from bales containing fibreboards into lift containers 43 at a lower level, as indicated by arrow F4 in FIG. 4 .

When the elevating container 43 is in a high position, its content is unloaded in a first cylindrical container 46, as shown by arrow F5, the cylindrical container 46 is equipped with a baffle plate 47 at its upper end, in case the fiberboard P falls into the cylindrical container of the exterior.

The first container 46 is mounted on a support 48 supported on an intermediate support 50a with a set of inserted springs 49 and shock absorbers not shown, the intermediate support 50a is supported at each corner with a scale 51 on a chassis 50b. The supporting member 48 is provided with two vibrating motors 52 on both sides thereof to increase the combined effect of the spring and shock absorber to vibrate the first container 46 . The two motors operate at a constant speed to generate enough vibration in the cylindrical container 46 to make the fiberboard vibrate up along the helical slope 53 arranged on the cylindrical inner wall of the first container 46 .

As shown in Figures 5 and 6, the fiberboard rotates counterclockwise and rises from the bottom of the container towards the top, as shown by arrow F6, and an articulated arm 54 is arranged on top of the container 46 to move the fiberboard either toward an intermediate channel 55, As indicated by arrow F7 (see FIG. 5 ), or towards a plate 56 inclined towards the center of the container 46 to return the fiberboard to the bottom of the container, as indicated by arrow F8 (see FIG. 6 ). As indicated by line 57 , the articulation of arm 56 is electric, the motor of which can be controlled by central control unit U via sensor 70 .

The guide grooves 55 are provided with fingers 58 positioned parallel to each other substantially in the direction of movement F7 of the fibreboards, allowing a better distribution of the fibreboards. Guide groove 55 leads to the top of the center of a smaller second cylindrical container 59, container 59 also has a support 60, two vibration motors 61, a group of springs and shock absorbers are installed on the support 60 on both sides 49 is installed on the above-mentioned intermediate support 50a. The second small container 59 also has a helical slope 63 on its inner wall to make the fiber and/or fiberboard rotate counterclockwise and rise from the bottom to the top, as shown by arrow F9 in FIG. 5 . The helical ramp 63 opens at its top into a second channel 64 which extends radially towards the outside of the container and opens above the vibrating tank 41 equipped with a vibrating motor (not shown). The vibrating fingers can be arranged at the outlet of the guide groove 64 . Vibration tank 41 is installed on a column 66 by spring 65 at its upstream end, and is suspended on the frame B by spring 67 at its downstream. At the upstream end of the vibrating tank 41, at least one nozzle 68 spraying water from the water network can be arranged, and a valve 69 can regulate the flow rate through the central control device U, for example. In an embodiment, the vibrating tank 41 may be filled with about half a centimeter of water to glue the fiberboard. The passing direction of the fiber in the vibrating groove 41 is indicated by the arrow F10. The fibers and water or solvent fall from the vibration tank 41 onto the above-mentioned second conveyor belt 19 . In a preferred embodiment shown in Figures 3 and 4, the nozzle 68 is positioned above the final channel 64 to allow the fibers to be wetted for an extended period of time before they fall onto the conveyor belt.

As shown in Figure 4, the batcher D is placed on the ground S, or placed on a trailer, like the frame B.

A height detector, such as an ultrasonic sensor 70, is provided below the middle guide groove 55 to detect the height of the fibers in the second container 59, and automatically control the hinged arm 54 according to the height in the second container being greater than a predetermined maximum value of the mobile. Due to the juxtaposition of the two containers, it is possible to avoid inhomogeneities in the supply and distribution of the fibers at the outlet of the dispenser, which are unavoidable when using a single container.

The position of the articulating arm 54 relative to the intermediate channel 55 is controlled electronically based on information provided by the sensor 70 to vary the supply of fiber from the first container 46 to the second container 59 .

Obviously, other systems for distributing fibreboards towards the conveyor belt of the apparatus of the invention can be configured.

In an embodiment, it is possible to choose a fiberboard P whose metal fibers consist of substantially cylindrical wires having a substantially straight longitudinal central portion which is extended on each side by an inset portion , the embedded part has a tip-curved end portion, the shape of the tip-curved end portion is a shape that does not connect two adjacent fibers, and the metal wire:

- a diameter of 0.38 to 1.05 mm,

- a total length of 19 to 80 mm,

- the length of the end part is 1.5 to 4 mm,

- has a lateral distance of at least 0.75 mm between the central part and each end part,

- a top bending angle determined between each embedded part and the central part equal to a minimum of 20°, and

- the angle obtained between each embedded part and the central part is less than or equal to 160°,

- get an angle between each embedded part and the end part, and

-Have a minimum tensile strength of 900 N/mm².

The wires constituting the fibers advantageously have a diameter of 0.65 to 0.85 mm and an overall length/diameter ratio of 65 to 85. In particular, the fibers have an overall length/diameter ratio of about 80. According to one feature, each top curved end portion is formed from a straight portion connected to the central portion by said inclined portion having at least two bends.

The fibers used in the present invention are advantageously fibers having a diameter of 0.75 mm, an overall length of 60 mm, and a tensile strength of at least 1100 N/mm2, such as those under the trademark Dramix 80/60".

The fiberboard P comprises fibers f1 , f2 . . . fn, for example 20 in total.

In the example described here, the metal fibers were dropped onto the first two layers of pellets before being poured into the third layer of pellets.

The second conveyor belt 19 discharges the aggregate of pellets and fibers onto a third conveyor belt 79 which leads to an agitator 80 .

The apparatus of the present invention comprises one, two or more storage containers 81, each containing a hydraulic binder, such as a standard cement (Portland cement) or lime slag cement, or a road cement. Binder, such as the product with the trademark "LIGEX" produced by CALCIA. The lower outlet of each storage container 81 leads to a pipe equipped with a worm 82 for conveying the adhesive to a hopper 83 . Hopper 83 may receive hydraulic binder from a storage container. The lower outlet of the hopper 83 leads to another delivery worm 84, and the worm 84 delivers the hydraulic binder to a weighing conveyor belt 85 in a casing 78, and one end of the weighing conveyor belt 85 is connected to a strain gauge 86. Connection, used to weigh the hydraulic binder.

Obviously, the height sensor 70 , the scale 51 and the other electric motors of the doser D are connected to the central control unit U via different lines 71 to 73 .

Weighing conveyor belt 85 conveys the hydraulic binder to a double conveyor belt equipped with two conveying worms 87, so that said A hydraulic binder is introduced into the agitator 80 described above.

The stirrer is also supplied with stirring water through the water network, as indicated by valve 88, and with plasticizing additive contained in a container 89. A mixing valve 90 can mix the additive from the container 89 with the water from the water grid 88 . The mixture of water and additives is distributed into the mixer 80 through a network of pipes 91 drilled with holes for injecting the mixture into the mixer above the two mixing shafts 92 . As shown in FIG. 8 , the pipe network 91 advantageously has an inlet simultaneously feeding the mixture on both sides of the stirrer, and the pipe network includes a parallel U-shaped flow guide above the stirring shaft 92 . Each stirring shaft 92 has radial blades 93 provided at their ends with plates inclined to form a discontinuous helical ramp. The blades of each mixing shaft are spaced to mix the entire composition of the fiber-reinforced compacted concrete when driving the two mixing shafts in opposite directions, as indicated by arrow F11 in FIG. 8 .

In the example, with a proportion (by weight) of 0.8% of the hydraulic binder, the additive makes it possible to delay the setting of the concrete for several days.

At the outlet of the agitator 80, the concrete and fiber mixture reaches a fourth conveyor belt 99, which conveys the composition to a hopper 100, the bottom of which is closed by a cover which consists of two Swing arm 101 is formed, and these two arms are suitable for separating, so that the compound that is contained in the hopper 100 is unloaded on a truck 102.

The unlatching of swing arm 101 is controlled by the person in charge of equipment of the present invention, so that unloading to truck.

The central control unit U is connected to a terminal comprising a screen 110 and a keyboard 111 for inputting command values for the feed quantities of the various compounds and the speeds of the various conveyor belts.

Figure 9 shows a page of the screen 110 at work in one embodiment of the method of the present invention.

As shown in Figure 9, D1 shows crushed stones with a diameter of 5 to 12 mm, a feed rate of 75.4 tons/hour, and a natural water content of about 1.70%, which are used to make up 44% of the fiber-free concrete dry composition , D2 shows silt with a diameter of 0 to 4 mm, a feed rate of 48.3 t/h, and a water content of 4.30%, which are used to make up 27.30% by weight of a fiber-free concrete dry composition, and D3 shows Wet silt with a diameter of 0 to 4 mm, a feed rate of 28.9 t/h, and a moisture content of 8.40% for a dry composition of fiber-free concrete of 15.80% by weight, D4 to D6 can be shown Other types of crushed stone or aggregate, but not used in this example, P1 shows a hydraulic binder supplied at a feed rate of 21.7 t/h for constituting 12.9% by weight of fiber-free concrete dry Composition, P2 can be another additive (e.g. fly ash) added to P1, X1 is a raw material additive that constitutes 0.35% (dry weight) of the hydraulic binder P1, corresponding to 80 kg/h Or the supply rate of 80 liters/hour, X2 or X3 can be other additives, E shows mixing water, accounts for the ratio of 5.20% (weight) of concrete dry material, and supply rate is 3.3 tons/hour.

Obviously, the amount of water to be supplied is not equal to 5.5% of the total flow of the machine because the pellets D1 to D3 are not dry but contain moisture.

The actual water consumption to be supplied will be calculated below. For this, starting from the total machine flow, ie the wet amount of fiber-free concrete fed by the machine, the total machine flow corresponds to 177.6 t/h, ie the sum of the feed quantities of compositions D1 to D3, P1 and E.

To find the dry weight supplied by the plant, excluding fibers, divide the wet weight by 1+5.2%=1.052, which equals a total dry weight of 168.8 tons/hour.

Therefore, the theoretical water consumption is equal to this total dry volume of 168.8 tons/hour×5.2%=8.78 tons/hour.

The amount of water from pellets D1 is equal to 0.44 x 168.8 x 0.017 = 1.26 tons/hour of water. Likewise, the amount of water in pellet D2 is equal to 0.273×168.8×0.043=1.98 tons/hour of water. For D3, the amount of water equal to 0.158×168.8×0.084=2.24 tons/hour of water, or the total amount of water equal to 5.48 tons/hour for all pellets from D1 to D3 is deducted from the theoretical water amount of 8.78 tons/hour, or 3.3 tons/hour , which is the amount of water that will actually be supplied to the blender.

The inventive plant uses a feed rate of 177.6 t/h, which corresponds to only 60% of its standard capacity of about 400 t/h, here limited to 300 t/h due to the capacity of the hydraulic binder batcher used .

The aggregate used may consist of 70% to 100% crushed material with acute angles and a nearly square shape, with a particle size of 0 to 14 mm, to avoid segregation, the phenomenon of separation of large particles. The concrete composition preferably also includes a plasticizing additive, which is convenient for intergranular lubrication and densification, and can obtain a fiber-free wet concrete with a density close to 2400 kg/m3, which has good effect, high strength, and can reduce water Hard binder ingredients.

The optimum moisture content was determined by a modified Portuguese test and varied between 4 and 6% of the dry composition of the concrete.

The composition is advantageously such that the hydraulic binder content is approximately 250 to 300 kg per cubic meter of dry concrete without fibers and the water content is 4 to 6% of the dry mass of concrete without fibers, or approximately 100 to 150 liters of water per cubic meter of concrete , The metal fiber batching is 30 to 40 kg per cubic meter of fiber-free dry concrete. In an example, the composition comprises 280 kg of hydraulic binder and 110 liters of water per cubic meter of fiber-free dry concrete.

The composition also advantageously comprises 0.3 to 1.8% by weight of hydraulic binder of a plasticizing retarder.

In addition, the timely and accurate dosing of fibers between -5% and +10% obtained using the apparatus of the present invention cannot be obtained with a mixer truck. The continuous plant of the present invention has a production rate of 200 to 1000 t/h of concrete, whereas the non-continuous plant generally does not reach half this rate.

Apparently, although the present invention has been described in conjunction with an embodiment, it is not limited thereto, and the present invention includes the equivalent technical means of the components and combinations thereof without exceeding the scope of the present invention.

Claims (15)

1. A method of manufacturing a compacted concrete composition reinforced by metal fibers on a continuous plant, comprising the steps of: (1) Continuously supply multiple pellets (D1, D2, D3, D4) transported on one conveyor belt (9, 19, 79), (2) continuous feeding of metal fibers (f1, f2...fn) from a vibrating dispenser (D) onto said conveyor belt, (3) The aggregates and fibers conveyed by the conveyor belt, a hydraulic binder (P1) and mixing water (E) are continuously supplied to a mixer (80), which may include one or more additive; It is characterized by: In said step (1), a solvent, such as water, for dissolving the glue that holds the fibers into sheets is supplied to the conveyor belts (9, 19, 79), said solvent being supplied by the dispenser (D) The fibers (f1, f2...fn) are fed onto the conveyor belt at or near the landing point; The step (2) is to supply the pre-coated metal fiber board (P) to the vibrating batcher, so that the fiber board and/or the degummed fibers are transported to the conveyor belt of the step (1), and the fibers are Cubic meters of fiber-free concrete dry material are supplied at a ratio of 25 to 60 kg of fibers; and Step (3) is to supply the hydraulic binder at a ratio of 180 to 400 kilograms per cubic meter of fiber-free concrete dry material, and the ratio of stirring water is determined to be a continuous supply of a mixer with a water content of per cubic meter of fiber-free concrete dry material. Fiber-reinforced compacted concrete composition fed 90 to 150 liters of water. 2. The method according to claim 1, characterized in that the batcher (D) comprises at least one vibrating batching container (46, 59) and a vibrating tank (41) or a weighing conveyor belt in sequence. 3. The method according to claim 2, characterized in that solvent is supplied to the oscillating trough so that the fibers (f1, f2...fn) are at least partially immersed in the oscillating trough filled with solvent at the bottom thereof, and with The solvents are fed together from the vibrating trough onto conveyor belts (9, 19, 79). 4. The method according to claim 1, characterized in that the solvent is sprayed onto the conveyor belt (9, 19, 79) with at least one nozzle located downstream of the landing point of the fibers (f1, f2...fn) . 5. The method according to one of claims 1 to 4, characterized in that the fibers (f1, f2...fn) are fed onto conveyor belts (9, 19, 79) for incorporation of fibers into various granular materials. 6. The method according to one of claims 1 to 4, characterized in that, according to the inherent water content calculation of each pellet (D1-D3) supplied in step (1) in the step (3) supplied to The proportion of stirring water (E) in the stirrer (80). 7. according to the described method of one of claim 1 to 4, it is characterized in that, in step (1) supply the full-scale aggregate of 83 to 93% (weight) of fiber-free concrete dry material, in step (3) with A cement (P1) or a road binder is supplied in a proportion of 7 to 17% by weight of the dry mass of fiber-free concrete, wherein 0.3 to 1.8% by weight of the hydraulic binder is added by a Concrete set delaying additive (X1) and/or plasticizer added to the mixing water to lubricate inter-particle contact and delay the setting of concrete. 8. A continuous plant for implementing the method according to one of claims 1 to 7, comprising: - a series of hoppers (1, 11, 21, 31) arranged at intervals on a motorized conveyor belt (9, 19, 79), each hopper being suitable for feeding a pellet (D1, D2, D3, D4) sent to the conveyor belt, each hopper is connected to a volumetric or gravimetric device (2, 12, 22, 32) for determining the quantity of pellets conveyed by said hopper, - a vibrating doser (D) suitable for feeding the metal fibers (f1, f2...fn) onto the conveyor belt, said doser is connected with a gravimetric device (51) for measuring the quantity of delivered fibers ) are connected, - one or more containers (81) for filling hydraulic binder (P1), each container distributes a kind of hydraulic binder (P1), and each container is related to a quantity of the binder distributed The measured gravimetric or volumetric device (86) is connected, and another container can be used for distributing a kind of supplementary powder, such as fly ash, - a stirring water feeder (88), said feeder is connected with a stirring water volume regulator (90), - a stirrer (80), said stirrer comprises a nozzle network (91) that agitation water is injected into the mixing chamber, and said nozzle network is supplied with agitation water by said water volume regulator (90), hydraulically bonded The agent is conveyed from said container to the inlet of the mixer, the fiber and granular composition is sent by the conveyor belt to the mixer for the mixing of all compositions of the compacted concrete reinforced by fibers, It is characterized in that this device comprises a solvent feeder (69) to deliver a solvent to the conveyor belt (9, 19, 79) at or near the outlet of the vibratory doser (D), said solvent Used to dissolve the glue of the fibreboard (P), thus releasing the pre-glued metal fibers of the board (P) dispensed by said dispenser. 9. Plant according to claim 8, characterized in that the solvent feeder (69) is arranged downstream of the first pellet supply hopper (1) and upstream of the last pellet supply hopper (21) Deliver solvent. 10. Apparatus according to claim 8, characterized in that the vibrating batcher (D) comprises a first vibrating container (46) having a helical bevel (53) on its cylindrical inner wall , the fiberboard (P) is suitable for vibrating movement from the bottom of the container towards the top on this helical slope, which is extended at its top by an intermediate groove (55) leading to a second vibrating container Above (59), the second vibration container also has a helical slope (63) on its cylindrical inner wall, and the fiberboard is suitable for moving from the bottom of the second vibration container to the top on this helical slope, and the second vibration The helical ramp of the container leads to a vibrating trough (41) which feeds fibers onto a conveyor belt (9, 19, 79), said solvent supply comprising at least one nozzle(68) on the 11. The apparatus according to claim 10, characterized in that said intermediate slot (55) comprises parallel vibrating fingers (58) substantially positioned on a vertical plane with their upstream ends fixed and their downstream ends free. ) in order to be able to separate the stacked fibreboards to obtain a more even distribution in the supply of fibreboards (P) to the second container, the longitudinal extension of the fingers being parallel to the direction of movement of said fibreboards (F7). 12. The apparatus according to claim 10 or 11, characterized in that the first vibrating container (46) comprises an articulated arm (54) interposed between the top of the helical ramp (53) and the intermediate groove (55), The arms are adapted to block access to the central trough in a closed position, feeding fibers back to the center and bottom of the first vibrating container, and to pass a controlled amount of fibers towards the central trough in a variable open position. 13. The apparatus according to claim 12, characterized in that the second vibrating container (59) is equipped with a height detector (70) that detects the height of the fibers in the second vibrating container, the detection The device is connected to a control motor of the articulated arm (54) to move said arm towards its closed position or towards its open position when the amount of fibers in the second vibrating container exceeds or falls below a predetermined limit value. 14. Apparatus according to claim 13, characterized in that the second container (59) is equipped with a frequency modulator to vary its vibration and its fiber supply, said modulator being able to be fed by the outlet of the second container The fiber quantity is controlled by the weigher. 15. The plant according to claim 8, characterized in that it is equipped with a central control unit (U) which is connected with hoppers (1, 11, 21, 31), containers (81) and The various volume or weight detectors of the batcher (D) and the water volume regulator (90) of the mixing water supply are connected so that according to the water content, the supply amount of each pellet (D1 to D3) and/or The supply amount of solvent calculates and controls the amount of water (E) supplied to the stirrer (80).

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