EP0201577B1

EP0201577B1 - Machine for the production, spreading and packing of dry concrete especially for road construction

Info

Publication number: EP0201577B1
Application number: EP85905825A
Authority: EP
Inventors: Heikki Peltoniemi
Original assignee: Individual
Current assignee: PELTONIEMI, HEIKKI
Priority date: 1984-11-14
Filing date: 1985-11-14
Publication date: 1990-01-31
Anticipated expiration: 2005-11-14
Also published as: DE3575751D1; FI79582C; EP0201577A1; FI844463A0; FI844463L; WO1986002963A1; FI79582B

Abstract

In said method, casting is performed in continuous action from a moving vehicle, wherein aggregate (7) is continuously delivered into an open-bottom discharge silo (8), the mass flow rate of passing aggregate (7) is monitored and, depending thereupon, binder (12) is continuously fed into the same discharge silo (8), aggregate (7) and binder (12) are mixed in discharge silo (8) while effecting the spreading of mixed dry concrete stock (14) through the open bottom (9) of silo (8), and the spread stock (14) is packed in a per se known manner by means of packing elements (3, 16, 17) mounted on the spreading vehicle.

Description

- The invention relates to a vehicle for making, spreading and packing a paving material comprised of an aggregate and a binder, said vehicle comprising a body, front support means at a leading end of said body, aggregate storage means on said body adjacent said leading end, a vertically arranged discharge silo at the rear section of said storage means, the bottom end of said discharge silo being provided with a downwardly open horizontally arranged cross-wise outlet, means for delivering metered quantities of aggregate from said storage means to a mxing area adjacent the top of said silo, a binder tank on said body, means for delivering metered quantities of binder from said tank to said mixing area, means in said mixing area for combining said binder and aggregate, spreader blade means in a trailing position relative to said outlet, means for vertically adjusting the position of said blade means, and means for advancing said vehicle along said surface to be paved.
An apparatus for road building of this known type is described in US-A-2 201 493 comprising a carriage frame with front and rear flanged wheels and a secondary frame supported by said main frame. The latter extends across the road way and is adapted to be raised and lowered relative to the main frame by hand-actuated jacks. Mounted on the secondary frame is a picking-up mechanism for scooping soil or road material transporting upwardly and discharging it into a throat of a hopper mounted on the secondary frame. At the throat opening an adjustable valve member is arranged for regulating the passed portion of the road material since the overflow material is carried away by a spiral screw member. Into the throat opening further flows at least one discharge spout of a second hopper for a suitable admixture and having a control valve for regulating the delivery of the admixture material into the first hopper. The road material and the binder are mixed in the mixing hopper which has an open bottom extending across the road way. For compacting the mixture vibration means, also attached to the secondary frame, are submerged in the discharged material from the open bottom. Alternatively to this vibration means in one embodiment the known apparatus is provided with a weighted roller positioned rearwardly of the discharge chute and adjustably supported on the secondary frame through spring balanced bars in a sleeved bracket. Pivotally attached to the rear end of the discharge of the hopper is a screed member which is adjustable supported by the secondary frame. For movement along the roadway the apparatus is supported by pre-laid track members which takes much time and is costly. A further disadvantage of the known apparatus is the unsufficient compacting of the paving material for a predetermined depth even if the vibration mechanism or alternatively the weight roller is in use which is subject to broken pavements when loaded later on. Also the adjusting of the secondary frame causes a long manipulating time required with these hand actuated devices.
From US-A-4 231 678 there is known a paving machine comprising a body which includes a hopper for storing material to be laid and an outlet for discharging it and which is supported by wheels at the front end and by a rotatable roller at the rear end of the machine. A screed plate is positioned between the roller and the wheels to form a layer thickness of the material. The wheels, the roller and the screed plate are vertically adjustable by means of rams interposed between the body of the machine and the supports and the screed plates, respectively. The spreading method of this known machine provides that the rams of the roller are controlled for adjusting the height of the rear end of the machine in accordance with the packing factor of the paving material. Otherwise it would not be possible to guarantee an even surface. Depending on the packing factor, the rear end sinks more or less. However, because the material cannot be added after the screed plate and because there are no means responsive to the variation of the packing factor, the machine does not operate so that evenness of the surface can be reached.
From DE-A-19 04783 there is known a tandem roller for packing paving material comprising two rollers, one of them being a vibrating roller.
Also from an article in "Straf3en-und Tiefbau", vol. 36 (1982), 6, pages 35, 36, 39, 40, the application of dry concrete technique to road construction is known.
The subject of the invention is therefore to provide an improved vehicle which easily enables the laying of a deposited layer with varying thickness and simultaneously forming the paving material with high compactness and which vehicle is also suitable for dry concrete technique.
The problem is solved essentially by the characterizing part of claim 1. The device according to the invention enables the laying of a deposited layer of varying thickness without the necessity of supplying leveling tracks or like members. By making the roller means height adjustable relative to the body of the vehicle, and by supporting the weight of the rear end of the vehicle substantially entirely on the roller means, the depth of the paving material is automatically modified, since the material deposited from the hopper will be a function of the height of the rear end of the vehicle. By adjustment of the vertical position of the leading end of the machine, the height of the spreader blade, and thus the layer thickness, is pre-adjusted. The fine adjustment of the layer thickness is effected by adjusting the vertical position of the rear end of the machine. Simultaneously and combined height adjustment of the leading and rear ends of the machine enables proper operation of the surface finalizing means, i. e. vibrating roller means and drum roller means. The drum roller means adjacent the rear end of the body and the vibrating roller means disposed in the leading position relative to the drum roller means lead to a very strong compaction of the discharge material. Also the inclinations of the road surface can be attached by this height adjustment, e.g. with different adjustments at each side of the machine.
A prefered embodiment of the invention is characterized in that a drag means is disposed in a trailing position relative to said drum roller means whereby final surface finish is effected.
The invention is further directed to the vehicle disclosed when used for constructing roads, by the dry concrete technique. By applying the dry concrete technique, wherein practically no water is mixed with the concrete, the amount of cement required for a desired concrete strength can be reduced compared to concrete traditionally used for road construction. It has been found that the dry concrete method is about 22-25% more favourable, particularly by virtue of its low water cement ratio. Thus, the consistence of stock to be spread will be 36 Vb° or even tougher.
The invention will now be described in more detail with reference made to the drawings in which

Fig. 1 shows an embodiment of a machine according to the invention for the production, spreading and packing of dry concrete, and
Fig. 2 shows a further developed embodiment of a drag means mounted on a machine according to the invention for finishing the surface.

Fig. 1 illustrates a machine intended for the production, spreading and packing of dry concrete, comprising a body designated by reference numeral 1, whose leading end is supported by roller wheels 2 fitted with caterpillar tracks and rear section is supported by a drum roller 3 and a vibrating roller 16. Roller wheels 2, drum roller 3 and vibrating roller 16 are mounted on body 1 by means of hydraulic cylinder means 4, 5, 23. By means of said piston- cylinder units 4, 5, 23 it is possible to adjust the height and position of body 1 relative to the ground and/or to hold the body on a desired level by controlling the operation of piston- cylinder units 4, 5, 23 by means of a water level instrument 24 and a scale of height 25.
At the leading end of the machine is provided a bin 6 for aggregate to be unloaded from a preceding truck. The rear section of bin 6 is fitted with a discharge silo 8 whose bottom end is provided with an outlet 9 crosswise of the machine. The bottom of aggregate bin 6 is provided by a conveyor belt 10 for delivering aggregate 7 into said discharge silo 8.
At the machine top section, above discharge silo 8 there is a binder tank 11 which is replenished with binder through a pipe 26 supplied from a tank truck travelling alongside the machine. The bottom section of binder tank 11 is fitted with a metering screw 27 and a shut-off valve 28 for controlling the amount of binder 12 delivered into said discharge silo 8.
In order to effect continuous casting, so-called slip casting from a moving vehicle, an up-and- down adjustable sluice gate 19 is provided for controlling the mass flow rate of aggregate delivered into the discharge silo 8, said mass flow rate being controllable both by means of sluice gate 19 and by varying the velocity of conveyor belt 10. The amount of aggregate 7 arriving in discharge silo 8 is monitored by means of a mechanical device 29 which measures the build-up of aggregate on said conveyor belt 10 and is connected to an electronic measuring means 30. For measuring the amount of aggregate the end of conveyor belt 10 is further provided with weighing sensors 32.
For the production of concrete meeting very strict strength requirements, a laser measuring device 31 is used instead of a mechanical measuring device 29.
The elements 29,31,32 for measuring the mass flow rate of aggregate 7 control the operation of the metering screw 27 and shut-off valve 28 of binder 12 in a manner that said binder 12 to be delivered into discharge silo 8 is in a desired proportion to the supplied aggregate 7.
The continuously delivered aggregate 7 and binder 12 find their way into a mixer 18 in the discharge silo 8, said aggregate 7 and binder 12 mixing in discharge silo 8 while at the same time the spreading of mixed dry concrete stock 14 proceeds through the open bottom 9 of silo 8. Between outlet 9 and mixer 18 is fitted a secondary mixer means 13, extending crosswise of the machine and being rotatable around a horizontal axis.
The build-up of casting stock 14 discharging through the outlet 9 of said silo 8 is determined by an adjustable spreader blade 15 moving along with body 1. Behind said spreader blade 15 is mounted a casting stock packing vibrating roller 16, followed by a static roller, a drum roller 3 for final compaction. The final surface finish is effected by means of a drag means 17.
A machine of the invention is provided with two independently operated drive motors (not shown), one being adapted to operate the equipment working in synchronism with the machine travelling speed and the other to operate the equipment substantially independent of the travelling speed. The former motor provides power e.g. for manoeuvering the machine, operating said gate 19 and for movements of conveyor belt 10 and metering screw 27. The latter motor, in turn, handles the vertical adjustment of body 1, compaction by means of vibrating roller 16, operation of drag means 17 as well as mixer 18.
In one preferred embodiment of the invention, between drum roller 3 and drag means 17 is provided a drum roller 20 connected to a hardening liquid reservoir 19. A rubber-coated drum roller 20 is moistened with hardening liquid 21 by means of a filter 33, excessive wetting of drum roller 20 being avoided by means of sealing rubber skirts 34, fitted around filter 33 and leaning against drum roller 20.
The hardening liquid reservoir 19, drum roller 20 for spreading the hardening liquid, and drag means 17 are combined into an integral unit that can 8₈ lifted and lowered relative to machine body 1.
The drag means 17 comprises two or more drag planks 22 in relative synchronized grinding motion, the compression load of drag planks on casting surface being controllable by means of hydraulic piston-cylinder units 35.
The invention has only been specified above by describing one preferred embodiment thereof. However, the invention is by no means limited to this embodiment but a plurality of modifications are conceivable within the inventive idea defined in the annexed claims.

Claims

1. A vehicle for making, spreading and packing a paving material comprised of an aggregate and a binder, said vehicle comprising a body (1), front support means (2) at a leading end of said body (1), aggregate storage means (6) on said body (1) adjacent said leading end, a vertically arranged discharge silo (8) at the rear section -of said storage means (6), the bottom end of said discharge silo (8) being provided with a downwardly open horizontally arranged cross-wise outlet (9), means (10) for delivering metered quantities of aggregate from said storage means (6) to a mixing area adjacent the top of said silo (8), a binder tank (11) on said body (1), means (27, 28) for delivering metered quantities of binder from said tank (11) to said mixing area, means (18, 13) in said mixing area for combining said binder and aggregate, spreader blade means (15) in a trailing position relative to said outlet (9), means for vertically adjusting the position of said blade means (15), and means for advancing said vehicle along said surface to be paved, characterized by the combination of

-rotatable mixing means (18, 13) in said discharge silo, wherein the weight of the paving material is substantially supported on said surface to be paved through an open bottom of said silo;

-a first hydraulic piston and cylinder means (4) between the body (1) and the front support means (2) for adjusting the vertical position of said leading end of said body (1), thereby adjusting the vertical position of said spreader blade means (15);

-a drum roller means (3) adjacent the rear end of said body (1);

-a vibrating roller means (16) disposed in leading position relative to said drum roller means (3);

- a second hydraulic piston and cylinder means (5) interposed between said body (1) and said drum roller means (3) for adjusting the vertical position of the rear end of said body (1) relative to a surface to be paved; and

-a third hydraulic piston and cylinder means (23) interposed between said body (1) and said vibrating roller means (16) for adjusting the vertical position of said rear end of said body (1) relative to the surface to be paved in combination with said second hydraulic piston and cylinder means (5).

2. A vehicle according to claim 1, characterized in that drag means (17) are disposed in a trailing position relative to said drum roller means (3).

3. The vehicle according to claim 1 or 2 when used for constructing roads by the dry concrete technique.