A METHOD AND A MACHINE FOR WORKING A CONCRETE SURFACE

Description

Field of the invention

[0001] This invention relates to a method of removing concrete from a concrete surface, for example to free the reinforcing bars in the road bed of a bridge, by ejecting a high pressure water jet from a nozzle that is kept close to the surface and reciprocated in parallel sweeps simultaneously with being oscillated transversely to the sweeping, and swinging the nozzle between the sweeps so that it is has an angle of attack in both sweeping movements.

[0002] The invention relates also to a machine for working a concrete surface down to the reinforcement of the concrete, comprising a vehicle on wheels having a transverse feed beam with a carriage that carries a water jet nozzle, where the nozzle is swingable about a first axis so as to give the jet an angle of attack in both directions when the carriage is reciprocated forth and back in working sweeps and swingable about a second axis so as to be oscillating in a plane transverse to feed beam.

Background of the invention

[0003] Road salting influences concrete road beds and the surface layer of road beds of concrete bridges need to be replaced after some years before the salt has penetrated down to the steel reinforcement; otherwise will the maintenance costs be very high. Therefore, one wants to remove the upper concrete layer to free the uppermost reinforcement layer and cast a new concrete surface layer before the uppermost reinforcement layer has been affected by the salt. Machines for such concrete removal are known for example by SE-451742-B, SE-508821-C, US-5361993-A, US-4854770, and US-4753549-A and others. One wants to remove all concrete around the reinforcement bars, but there will often be some concrete left on the underside of the bars.

Object of invention and brief description of the invention

[0004] It is an object of the invention to provide a method and a machine that permit the reinforcing rods to be freed completely from the concrete, that is, also the underside of the rods should be free from concrete. This object is fulfilled in principle by the use of two nozzles that are jointly swept and oscillated while held in an angle to each other so that the ejecting jets impinge on the concrete at different angles as seen in the direction of oscillation. The above defined carriage carries two jet ejecting nozzles that are jointly swingable about said axes and has an angle between their jet directions that is between 10 and 50 degrees as seen in the direction of the oscillation.

Brief description of the drawings

[0005] 

• Figure 1 is a top plan view of a machine shown as an example of the invention.
• Figure 2 is a side view of the machine shown in figure 1.
• Figure 3 is a close-up view of the front part of figure 2.
• Figure 4 is an enlarged perspective view of a twin nozzle arrangements shown in figure 2.
• Figure 5 is a side view of the twin nozzle arrangement.
• Figure 6 is a view of the nozzles shown in figure 5 seen towards the front ends of the nozzles as indicated by line 6-6 in figure 4.

Description of the preferred embodiment shown as an example of the invention

[0006] The machine shown in figures 1-2 consists of a vehicle carried by two front wheels 12,13 with built-in motors 14,15 and two rear wheels 16,17 by which it can be steered. The machine has a pillar 18 that is rotatable about an axis I and forms a guide for a carrier 20. The carrier 20 carries a mounting 21 for a feed beam or guide 22 that is transverse to an axis II about which the feed beam can be rotated. This arrangement provides for a great freedom in the positioning of the feed beam adjacent concrete surfaces in various positions and not only road beds.

[0007] The feed beam 22 carries and guides a carrier 23 with four wheels and the carrier has a built-in motor with pinjons meshing with a rack 25 on the feed beam. The carrier 23 has a holder 30 with a bifurcated lower portion 40 for two water jet nozzles 31,32 shown in figures 4-6. The feed beam 22 has a protection hood 33 with a rubber shield 34 and the holder 30 extends down into the hood through a slot 35 formed by rubber sealings 36,37.

[0008] The holder 30 is swingable about an axis III by means of a hydraulic cylinder 27 so as to provide for a suitable angle of attack of the jets forwards in the carrier moving direction when the carrier moves in the one direction as well as in the opposite direction. Additionally, a motor 28 is arranged to oscillate the holder 30 about an axis IV transverse to the axis III in figure 5 and the central position of the holder 30 as well as its two end positions are indicated in figure 2.

[0009] Figure 4 shows in a perspective view and figure 5 in a side view the lower portion 40 of the holder 30 with the two nozzles 31,32. This portion 40 is screwed to the main portion of the holder 30 and it is bifurcated into two branches 41,42 that have the two nozzles 31,32 screwed into their ends. The nozzles are obliquely directed towards each other so that the jets ejected from them cross at a distance of for example 10 cm from the nozzles. The jets are indicated as lines 50,51 in figure 5. As can be seen from figure 6, the branches 41,42 are somewhat twisted so that the jets cross but do not meet. The difference in directions between the jets is shown as about 30 degrees in the plane of the paper in figure 5, that is, the angle v is about 30 degrees and it should be between 10 and 50 degrees or between 10 and 40 degrees or preferably between 20 and 40 degrees. The nozzle holder 30,40 is oscillated in the plane of the paper in figure 5, that is, transverse to the feed beam 22, through an angle that should be between 6 and 20 degrees and preferably between 8 and 15 degrees. The sum of half the angle v and half the oscillation angle should be at least 15 degrees and preferably at least 20 or 22 degrees.

[0010] When the nozzle holder 30,40 is oscillated during a sweeping motion, in each sweep, the jets 50,51 will cut a comparatively wide path in the concrete because of the oscillation. Between the sweeps, the entire machine is preferably stepped a step smaller than the width of the path so that the concrete is cut more than once. The width of the path can for example be 15 cm and the steps can be less than half the width of the path, for example one third thereof the sweeps, sweeps.

[0011] The operation of the machine will now be described.

[0012] The carrier 23 is moved in one direction along the feed beam with its nozzle holder 30 in an attack angle and the nozzle holder is oscillated transversely thereof at a high speed as compared with the speed of the carrier. The carrier can for example move at a speed of 5-10 m/s and the oscillation frequency can for example be 40-400 double strokes per minute. In connection with the carrier reaching its turning point, the entire machine is stepped forwards a step that is smaller than the path of cutting made by the oscillating jets and the nozzle holder 30 is swung back into an attack angle in the new sweeping movement. By having two nozzles which give different attacking angle of the impinging jets, one will get a better freeing of the reinforcing rods irrespective of the directions of the rods in the concrete and also a good freeing at the crossing points of rods perpendicular to each other.

Claims

1. A method of removing concrete from a concrete surface, for example to free the reinforcing bars in the road bed of a bridge, by ejecting a high pressure water jet from a nozzle (31,32) that is kept close to the surface and reciprocated in parallel sweeps simultaneously with being oscillated transversely to the sweeping, and swinging the nozzle between the sweeps so that it is has an angle of attack in both sweeping movements,
characterised in that
two nozzles (31,32) are used, which are swept and oscillated together and kept at an angle to each other so that the jets (50,51) attack the concrete surface at different angles as seen in the direction of the oscillation, and the difference in angle is maintained fixed.

2. A method according to claim 1, characterised in that, during the oscillation, the difference in directions between the jets (50,51) is between 10 and 50 degrees as seen in the plane of oscillation.

3. A method according to claim 2, characterised in that the difference in directions between the jets is between 20 and 40 degrees as seen in the plane of oscillation.

4. A method according to any one of the preceding claims, characterised in that the two jets are oscillated together through an angle that is between 6 and 20 degrees.

5. A method according to claim 4, characterised in that the two jets are oscillated together through an angle that is between 6 and 15 degrees.

6. A method according to any one of the preceding claims, characterised in that the jets are directed towards each other.

7. A method according to claim 6, characterised in that the sum of half the difference in the direction between the two jets in the plane of oscillation and half the angle of oscillation is at least 15, preferably at least 22 degrees.

8. A method according to any one of the preceding claims, characterised in that a path of concrete is worked in each sweep by the jets of the two oscillating nozzles (31,32) and the nozzles are stepped between the sweeps a distance less than the width of the path.

9. A machine for working a concrete surface down to the reinforcement of the concrete, comprising a vehicle (11) having a transverse feed beam (22) with a carriage (23) that carries a water jet nozzle (31,32), where the nozzle is swingable about a first axis (I) so as to give the jet an angle of attack in both directions when the carriage is reciprocated forth and back in working sweeps and swingable about a second axis (II) so as to be oscillating in a plane transverse to feed beam,
characterised in that
the carriage (23) carries two nozzles (31,32), which are commonly swingable about said axes (I,II) and are at a constant angle to each other and have a difference between their jet directions that is between 10 and 50 degrees as seen in the plane of oscillation.

10. A machine according to claim 9, characterised in that the difference between the jet directions of the two nozzles (31,32) is between 20 and 40 degrees as seen in the plane of oscillation.

Ansprüche

1. Verfahren zum Entfernen von Beton aus einer Betonoberfläche, zum Beispiel, um die Verstärkungsstangen in der Bettung einer Brücke freizulegen, durch einen Hochdruckwasserstrahl aus einer Düse (31, 32), der nahe an der Oberfläche gehalten wird, sich in parallelen Durchläufen hin- und herbewegt, gleichzeitig quer zu den Durchläufen geschwungen wird, und durch Schwenken der Düse zwischen den Durchläufen, so dass sie einen Ansatzwinkel in beiden Durchlaufbewegungen hat, gekennzeichnet dadurch, dass zwei Düsen (31, 32) verwendet werden, die zusammen bestrichen, geschwungen und in einem Winkel zueinander gehalten werden, so dass die Strahlen (50, 51) die Betonoberfläche in verschiedenen Winkeln, in der Richtung der Schwenkung gesehen, angreifen, und der Unterschied im Winkel beibehalten wird.

2. Verfahren nach Anspruch 1, gekennzeichnet dadurch, dass während der Schwenkung, die Differenz der Richtungen zwischen den Strahlen (50, 51) zwischen 10 und 50 Grad beträgt, in der Schwenkungsebene gesehen.

3. Verfahren nach Anspruch 2, gekennzeichnet dadurch, dass die Differenz der Richtungen zwischen den Strahlen zwischen 20 und 40 Grad beträgt, in der Schwenkungsebene gesehen.

4. Ein Verfahren nach einem der vorigen Ansprüche, gekennzeichnet dadurch, dass die beiden Strahlen zusammen durch einen Winkel zwischen 6 und 20 Grad geschwenkt werden.

5. Verfahren nach Anspruch 4, gekennzeichnet dadurch, dass die beiden Strahlen zusammen durch einen Winkel zwischen 6 und 15 Grad geschwenkt werden.

6. Ein Verfahren nach einem der vorigen Ansprüche, gekennzeichnet dadurch, dass die Strahlen zueinander gerichtet sind.

7. Verfahren nach Anspruch 6, gekennzeichnet dadurch, dass die Summe der halben Differenz der Richtung zwischen den beiden Strahlen in der Schwenkungsebene und dem halben Schwenkungswinkel mindestens 15, vorzugsweise mindestens 22 Grad beträgt.

8. Verfahren nach einem der vorigen Ansprüche, gekennzeichnet dadurch, dass in jedem Durchlauf eine Betonbahn von den Strahlen der beiden oszillierenden Düsen (31,32) bearbeitet wird und die Düsen zwischen den Durchläufen in einem Abstand abgestuft sind, der geringer als die Breite der Bahn ist.

9. Maschine, um eine Betonoberfläche bis herunter zur Verstärkung des Betons zu bearbeiten, mit einem Fahrzeug (11), einer querlaufenden Vorschubstützeinrichtung (22) und einem Werkzeugschlitten (23), der eine Wasserstrahldüse (31, 32) trägt, wobei die Düse um eine erste Achse (I) schwenkbar ist, um der Düse einen Ansatzwinkel in beiden Richtungen zu geben, wenn der Werkzeugschlitten in Arbeitsdurchläufen vorwärts- und zurückbewegt wird, und um eine zweite Achse schwenkbar (II), um in einer Ebene quer zur Vorschubstützeinrichtung zu schwingen, gekennzeichnet dadurch, dass der Werkzeugschlitten (23) zwei Düsen (31,32) trägt, die gemeinsam um die besagten Achsen (I, II) schwenkbar sind, in einem konstanten Winkel zueinander sind und eine Differenz zwischen ihren Düsenrichtungen zwischen 10 und 50 Grad, in der Schwingungsebene gesehen, haben.

10. Maschine nach Anspruch 9, gekennzeichnet dadurch, dass die Differenz zwischen den Düsenrichtungen der beiden Düsen (31, 32) zwischen 20 und 40 Grad, in der Schwingungsebene gesehen, ist.

Revendications

1. Procédé pour enlever du béton d'une surface de béton, par exemple pour libérer les barres de renforcement de la base de la route d'un pont, en éjectant un jet d'eau à haute pression d'un gicleur (31,32) qui est maintenu près de la surface et inversé en passages parallèles étant en même temps oscillé transversalement par rapport au balayage,
et en tournant le gicleur entre les passages de façon à ce qu'il ait un angle d'attaque dans les deux mouvements de balayage, caractérisé en ce que
deux gicleurs (31, 32) sont utilisés, qui sont balayés et oscillés ensemble et maintenus à un angle l'un à l'autre de façon à ce que les jets (50, 51) attaquent la surface de béton à des angles différents comme vus dans la direction de l'oscillation, et la différence d'angle est maintenue fixe.

2. Procédé selon la revendication 1, caractérisé en ce que, pendant l'oscillation, la différence des directions entre les jets (50,51) est entre 10 et 50 degrés comme vus dans le plan d'oscillation.

3. Procédé selon la revendication 2, caractérisé en ce que la différence des directions entre les jets est entre 20 et 40 degrés comme vus dans le plan d'oscillation.

4. Procédé selon l'une quelconque des revendications précédentes, caractérisé en ce que les deux jets sont oscillés ensemble à travers un angle qui est entre 6 et 20 degrés.

5. Procédé selon la revendication 4, caractérisé en ce que les deux jets sont oscillés ensemble à travers un angle qui est entre 6 et 15 degrés.

6. Procédé selon l'une quelconque des revendications précédentes, caractérisé en ce que les jets sont dirigés l'un vers l'autre.

7. Procédé selon la revendication 6, caractérisé en ce que la somme de la moitié de la différence dans la direction entre les deux jets dans le plan d'oscillation et la moitié de l'angle d'oscillation est au moins 15, de préférence au moins 22 degrés.

8. Procédé selon l'une quelconque des revendications précédentes, caractérisé en ce qu'un parcours de béton est travaillé à chaque passage par les jets des deux gicleurs oscillants (31,32) et les gicleurs sont échelonnés entre les passages à une distance inférieure à la largeur du parcours.

9. Machine pour travailler une surface de béton jusqu'au renforcement du béton, comprenant un véhicule (11) ayant un axe d'alimentation transversal (22) avec un chariot (23) qui porte un gicleur de jet d'eau (31,32), où le gicleur est pivotant autour d'un premier axe (I) afin de donner au jet un angle d'attaque dans les deux directions quand le chariot est inversé en avant et en arrière dans des passages de travail et pivotant autour d'un deuxième axe (II) afin d'être oscillant dans un plan transversal à l'axe d'alimentation,
caractérisé en ce que
le chariot (23) porte deux gicleurs (31,32), qui sont habituellement pivotants autour desdits axes (I,II) et sont à un angle constant l'un de l'autre et ont une différence entre leurs directions de jet qui est entre 10 et 50 degrés vus dans le plan d'oscillation.

10. Machine selon la revendication 9, caractérisée en ce que la différence entre les directions de jet des deux gicleurs (31,32) est entre 20 et 40 degrés vus dans le plan d'oscillation.

Drawing