FI81862C - Foerfarande Foer framstaellning av en betongvaeg - Google Patents

Description

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Method for making a concrete road. - Forfarande for framstållning av en betongvåg.

The invention relates to a method for producing concrete roads from dry concrete mass. In this context, dry concrete mass means a mass which, at the time of application, has a flexibility of about 36 Vb ° or more, i.e. contains a maximum of 90 l / m · * of water.

The ground concrete used in the data has traditionally been manufactured in temporary concrete stations built in connection with aggregate depots. This has caused difficulty in starting a flexible and fast stabilization work in the escape. The water-cement ratio in the concrete produced has also been unfavorable, which, on the other hand, has meant that the semen content must have been disproportionately high in order to fasten the desired concrete strength.

Compared to the use of ground concrete, the dry concrete method, in which no water is actually added to the concrete at all, has been found in the study to be about 22-25% cheaper precisely due to the water-cement ratio. The mass to be applied is then 36 Vb ° or more rigid, i.e. it contains a maximum of 90 l / m 2 of water.

It is known that concrete usually has to be produced in quantities of several thousand cubic meters, so that the lower amount of cement required in the dry concrete method compared to the ground concrete makes up a very large part of the entire casting operation as a cost factor.

In the past, the dry concrete method has mainly been used mainly for the production of pipes, manhole rings and drive plates. The dry concrete method has not been used at all in road construction - despite its considerable advantages - because there have been no suitable machines for its application.

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Strassen- und Tiefbau 6/1982 describes the preparation and mixing of dry concrete mass into a finished mass in a concrete plant, adding 4-6% by weight of water to the mass. The finished mass is transported to the road construction site, where it is applied and compacted in the usual way using separate spreading and compaction machines. The production, transport, application and compaction of pulp at different stages make the manufacturing process large and expensive.

U.S. Patent 2,201,493 discloses a pulp application and compaction machine with a combined mixing and downcomer. The silo contains overlapping mixing grids that must be rocked back and forth to allow the pulp to flow through the ri spaces. If the silo were filled with mass resting in the ground through the open bottom of the silo, the mixing grids could not be rocked. Thus, there is no mass in the silo other than that which, when momentarily fed, collapses through the mixing grids. The thickness of the cast layer is determined by the instantaneous feed rate of the mass in relation to the flow rate. Such an arrangement would not be suitable for the purpose of the invention, since the dry concrete mass used in the manufacture of the road contains a relatively coarse aggregate which would block and roar the grate mixers moving back and forth.

In the method according to the invention, when applying dry concrete, it is essential that the mass is in the landing silo in the ground silo and the application thickness limits the open bottom of the landing silo by the amount of layer thickness.

A concrete road meeting sufficient strength requirements can be produced more economically by the dry concrete application method according to the invention, which is characterized in that the aggregate and cement are fed separately and in relation to each other from the bottom to an open landing silo 36 Vb ° or sitS stiffer, i.e. contains no more than 90 3 81 862 1 / m3 of water, and that this dry concrete mass, which is supported in the ground by the open bottom of the silo, is continuously lowered through the open bottom of the silo into a dry concrete slab with a thickness determined by the silo bottom. an opening-limiting expansion blade.

The structure and operation of the machine used to perform the method according to the invention will be described in more detail with reference to the accompanying drawing, in which

Figure 1 shows the machine seen from the side and partially open-cut.

Figure 2 shows an embodiment of a laak device for finishing a surface made by the method according to the invention.

The machine for the production, spreading and compaction of dry concrete shown in Fig. 1 comprises a frame indicated by reference numeral 1, the front end of which is supported by a track drum 2 with tracked discs and the rear part by a roller drum 3 and a roller roller 16. The roller drum 2, roller drum 3 and roller roller 16 are -from the frame 1 by means of hydraulic cylinder devices 4, 5, 23.

By means of said mantle cylinder devices 4, 5, 23 the height and position of the body 1 with respect to the ground can be obtained and / or the frame kept in the desired plane by controlling the operation of the mantle cylinder devices 4, 5, 23 with a spirit level device 24 and a height scale 25.

At the front of the machine there is a silo for 6 aggregates to be unloaded from the truck driving. At the rear of the silo 6 there is a landing silo 8, at the lower end of which there is a transverse landing opening 9. The bottom of the aggregate silo 6 is formed by a belt conveyor 10 which feeds the aggregate 7 into the landing silo 8.

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At the top of the machine, above the landing silo 8, there is a cement tank 11, which is supplemented with cement fed from a silo truck passing through the side of the machine through a pipe 26. The lower part of the cement silo 11 has a dosing screw 27 and a shut-off flap 28, which receive the amount of binder 12 to be fed to the downcomer 8.

In order to continuously carry out the casting from a moving vehicle, so-called strip casting, an up-down-adjustable dam hatch 19 is provided to control the mass flow of aggregate to be fed to the silo 8, whereby the mass flow can be controlled by both the damper 19 and the belt conveyor 10. The amount of aggregate 7 entering the landing silo 8 is monitored by a mechanical device 29 measuring the thickness of the aggregate layer on the belt conveyor 10, which device is connected to an electronic measuring device 30. In addition, for measuring the amount of aggregate, weighing sensors 32 are arranged on the end of the belt conveyor 10.

When manufacturing concrete that meets very high strength requirements, a laser measuring device 31 is used instead of a mechanical measuring device 29.

The mass flow measuring means 29, 31, 32 of the aggregate 7 control the operation of the dosing screw 27 and the shut-off flap 28 of the cement 12 so that the binder 12 to be fed to the downcomer 8 is in the desired ratio to the aggregate 7 to be fed.

The continuously fed aggregate 7 and the cement 12 enter the mixer 18 in the downcomer 8, whereby the aggregate 7 and the cement 12 are mixed in the downcomer 8 while the mixed dry concrete mass 14 is applied through the open bottom 9 of the silo 8. Between the downcomer 9 and the mixer 18 there is a cross-cutting post-mixing member 13 rotating about a horizontal axis of the machine.

The amount of thickness of the casting mass 14 coming from the lowering opening 9 of the downcomer 8 is 81,862. arranged towing device 17.

The machine according to the invention has two drive motors operating independently of each other (not shown), one of which is arranged to drive devices operating synchronously with the speed of movement of the machine and the other devices which are substantially independent of the speed of movement. The former motor provides power, for example, to the movements of the machine, to the movement of the door 19 and to the movements of the conveyor belt 10 and the dosing screw 27. The latter motor, in turn, manages the use of the height adjuster of the body 1, the compaction by means of the roller roller 16, the drive 17 and the mixer 18.

In a preferred embodiment of the invention, a roller drum 20 is arranged between the roller drum 3 and the drag device 17 in communication with the tempering liquid container 19. The rubber-coated roller drum 20 is moistened with the filter 33 by means of rubber beads 34 resting on the roller drum 20.

The hardening fluid bar 19, the roller drum 20 for applying the hardening fluid and the drag device 17 are formed as a single unit to be raised and lowered relative to the machine body 1.

The traction device 17 has two or more traction planks 22 which perform a synchronous frictional movement with each other, whereby the compression pressure of the traction planks 22 against the casting surface can be adjusted by means of hydraulic mantle cylinder devices 36.

The invention has been described above with reference to only one preferred embodiment thereof. However, it is not intended in any way to limit the invention to the tatM example in any way, but many modifications are possible within the scope of the inventive idea defined by the following claims. Thus, the coating layer may be cast as one solid slab or two slabs, the lower cement content of which may be lower than that of the upper tread.

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Claims (1)

A method for producing concrete roads from dry concrete mass, characterized in that the aggregate and cement are fed separately and in relation to each other from a bottom to an open landing silo, wherein the aggregate and cement are mixed into a dry concrete mass of about 90 Vb ° or more. l / m ^, and that tMta dry concrete mass supported in the ground by the open bottom of the silo is continuously calculated through the open bottom of the silo into a dry concrete slab, the thickness of which is determined by the spreading blade delimiting the silo bottom opening. 8 81862 Patent for the purpose of framstalllning av en betongvåg av torrbetongmas-sa, kånnetecknat darav, att ett stenmaterial and cement matas skilt for sig inbordes proportionate till en sinkingsilo med opt bottt, darr stenmaterialet or cementet blandas till en ° or, if necessary, at a rate of 90 1 / m3 of wattage, and in the case of torrential concrete, in which case the silos are placed on the surface of the label, som begrånsar silons bot-tenSppning. »* · Li