WO1986002963A1

WO1986002963A1 - Dry concrete spreading and packing method especially for road construction as well as machine for the production, spreading and packing of earth and dry concrete

Info

Publication number: WO1986002963A1
Application number: PCT/FI1985/000090
Authority: WO
Inventors: Heikki Peltoniemi
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-11-14
Filing date: 1985-11-14
Publication date: 1986-05-22
Anticipated expiration: 1987-05-14
Also published as: DE3575751D1; FI79582C; EP0201577A1; FI844463A0; FI844463L; EP0201577B1; 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

Dry concrete spreading and packing method especially for road construction as well as machine for the pro¬ duction, spreading and packing, of earth and..dry con¬ crete.

The present invention relates to a dry concrete spread¬ ing and packing method especially for road construction.

The earth concrete used for road construction has been traditionally prepared at temporary concrete stations built around aggregate supplies. This has caused trouble in getting stabilization work smoothly and rapidly underway. Further, the water-cement ratio has been unfavourable in thus produced concrete, one con¬ sequence being that the amount of cement had to be ex¬ cessively high to reach desired concrete strength.

•Compared with the use of earth concrete, a dry concrete method wherein practically no water is thus admixed se¬ parately with concrete has been experimentally found circa 22-25 % more favourable, particularly by virtue of its water-cement ratio. Thus, the consistency of a stock to be spread will be 36 Vb° or even tougher.

In road construction work it is generally necessary to produce concrete in amounts of several thousand cubic meters, the lower amount of cement needed .in dry con¬ crete technique as compared to earth concrete being a very significant cost factor in the whole casting pro¬ cess.

Dry concrete technique has been earlier applied pri¬ marily for producing pipes, well, rings, and walkway tiles. It has not. been possible, to. apply dry concrete technique to road construction - despite the consider¬ able advantages offered thereby - since proper machines have not been available, nor has been applied to stabilizing since compaction cannot be carried out with a conventional vibrating roller. Neither has dry concrete been capable of reaching, standardized strength and durability or air porosity content.

A dry concrete spreading and packing method of the in¬ vention is suitable for road construction and character¬ ized in that the casting is effected in a continuous operation from a moving vehicle wherein aggregate is being continuously supplied into an open-bottom dis¬ charge silo, that the supplied aggregate mass flow rate is monitored and_/depending thereupon, a binder is continuously fed into- the same discharge silo, that aggregate and binder are mixed in the discharge silo while spreading of the mixed dry concrete stock is effected through the open bottom of said. silo, and that the spread stock is packed in a conventional manner by means of packing elements mounted on the spreading vehicle.

The invention is further directed to a machine for pro¬ ducing, spreading and packing earth and dry concrete, said machine comprising a body whose leading end is supported by wheels or rollers fitted with caterpillar tracks and whose trailing section is supported by at least one drum roller, the bearing wheels and drum roller being mounted on the body by means of hydraulic piston-cylinder units for adjusting the height and position of the body relative to the ground and/or for holding the body on a desired level by controlling the operation of piston-cylinder units by means of position sensors, said machine further comprising a bin at the machine leading end for aggregate and a'discharge silo at the rear end of said silo, the bottom end of said discharge silo being provided, with an outlet crosswise of the machine, a conveyor belt acting as the aggregate bin bottom delivering the aggregate into said discharge silo, whereby the machine top sect¬ ion is further fitted with a binder tank provided with means for delivering binder, into said discharge silo, above the outlet of said discharge silo is mounted a feed screw extending crosswise of the machine and rotatable around a horizontal axis for levelling a required quantity of stock in the discharge silo, said machine further comprising an adjustable spreader blade for determining the build-up of the casting stock coming out of the outlet of said discharge silo, said blade being movable with the body, a vibrating roller for packing the casting stock mounted behind said spreader blade and finally. a drum roller and a drag means for finishing the cast surface.

A machine of the invention is characterized in that for carrying out the casting continuously from a moving vehicle, said machine comprises means for monitoring the mass flow rate of aggregate to be delivered into a discharge > silo, means for feeding a binder continuously, depending on the aggregate mass flow rate, into the same silo and means for mixing aggregate and binder contin¬ uously in said discharge silo.

The invention will now be described in more detail with reference made to the accompanying drawings, in which

fig. 1 shows a machine of the invention for the product¬ ion, spreading and packing of dry concrete.

Fig . 2 is a further developed embodiment of a drag means mounted on a machine of the invention for finish¬ ing the. surface. outlet crosswise of the machine, a conveyor belt acting as the aggregate bin bottom delivering the aggregate into said discharge silo, whereby the machine top sect¬ ion is further fitted with a binder tank provided with means for delivering binder into said discharge silo, above the outlet of said discharge silo is mounted a feed screw extending crosswise of the machine and rσtatable around a horizontal axis for levelling a required quantity of stock in the discharge silo, said machine further comprising an adjustable spreader blade for determining the build-up of the casting stock coming out of the outlet of said discharge silo, said blade being movable with the body, a vibrating roller for packing the casting stock mounted behind said spreader blade and finally a drum roller and a drag means for finishing the cast surface.

A machine of the invention is characterized in that for carrying out the casting continuously from a moving vehicle, said machine comprises means for monitoring the mass flow rate of aggregate to be delivered into a discharge . silo, means for feeding a binder continuously, depending on the aggregate mass flow rate, into the same silo and means for mixing aggregate and binder contin¬ uously in said discharge silo.

Fig. 2 is a further developed embodiment of a drag means mounted on a machine of the invention for finish¬ ing the. surface. Fig. 1 illustrates a machine intended for the product¬ ion, spreading and packing of dry concrete, comprising a body designated by ref rence numeral 1 , whose leading end is supported by roller wheels 2 fitted with cater¬ pillar 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 1£ 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 a 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 adjust¬ able sluice gate 19 is provided for controlling the mass flow rate of aggregate delivered into the dis- charge 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 connect¬ ed 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 continuosly 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 adjust¬ able spreader blade .15 moving along with body 1. Be¬ hind 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 in¬ dependently 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 maneuvring 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 hard¬ ening 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 10 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 be 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 compress¬ ion load of drag planks on casting, surface being con¬ trollable by means of hydraulic piston-cylinder units 36. The invention has only been specified above by describ¬ ing 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 dry concrete, spreading and packing method especial¬ ly for road construction, wherein casting is effected in continuous action from a moving vehicle, aggregate (7) is delivered in continuos action into a discharge silo (8), the mass flow rate of passing aggregate (7) is monitored and, depending thereon, binder (12) is fed in continuous action into the same discharge silo (8) , whereby the stock (14) spread from said vehicle is packed or compacted by means of packing elements (3, 16, 17) mounted on the spreading vehicle, c h a r a c t e r i z e d in that aggregate (7) and binder (12) are continuously mixed in an open-bottom discharge silo (8) while effecting the. spreading of mixed dry concrete stock (14) through the open bottom (9) of silo (8) over the entire width of said silo.

2. A machine for making, spreading and packing earth and dry concrete, said machine comprising a body (1), whose leading end is supported by wheels or caterpillar- equipped roller wheels (2) and whose rear section is supported by at least one drum roller' (3) , the bearing wheels (2) and drum roller (3) being mounted on body (1) by means of hydraulic piston-cylinder units (4, 5) for adjusting the height and position of the body relative to the ground and/or for holding the body on a desired level by controlling, the operation of piston-cylinder units (4, 5) by means of sensing elements, said machine further comprising a bin (6) at the leading end of a machine for aggregate and a discharge silo (8) at the rear section of said bin (6) , the bottom' end of said discharge silo being provided with, a crosswise outlet (9), a conveyor belt (10) that provides the bottom for aggregate bin (6) delivering, said aggregate (7) into discharge silo (8) , said machine further comprising an adjustable spreader blade (15) for determining the build-up of casting, stock (14) coming out of the outlet (9) of discharge, silo (8) , said blade moving along with body (1), a vibrating roller (16) behind, said spreader blade (15) for packing the casting stock, and finally means (3, 17) for finishing the cast surface, c h a r a c t e r i z e d in that said machine further comprises - for carrying out the casting in continuous action from a moving vehicle - means for monitoring the mass flow rate of aggregate (7) being continuously delivered into a discharge silo (8) , means for feeding binder (12) continuously, depending on the mass flow rate of aggregate (7) , into the same discharge silo and a mixer element (13, 18) for continuously mixing aggre¬ gate (7) and binder (12) in an open-bottom discharge silo (8) .

3. A machine as set forth in claim 2, c h a r a c t e r i z e d in that said, mixer element (13, 18) comprises a pre-mixer member (18) and a secondary mixer member (13)

4. A machine as set forth in claim 2 or 3, c h a r a c t e r i z e d in that upon the rear section of belt (10) is mounted an adjustable sluice gate (19) for regulating the thickness of aggregate layer (7) on said belt.

5. A machine as set forth in any of claims 2-4, c h a r a c t e r i z e d in that the machine is provided with two drive motors operating independently of each other, one motor being adapted to operate the equipment working in synchronism with the travelling speed of the machine and the other to operate the equipment which is substantially independent of the travelling speed of the machine.

6. A machine as. set forth in any of claims 2-5, c h a r a c t e r i z e d in that, between a drum roller (3) and. a drag means (17) is mounted a drum roller (20) connected to a hardening liquid reservoir (19) for spreading hardening liquid (21).

7. A machine as set forth in any of claims 2-6, c h a r a c t e r i z e d in that said hardening liquid reservoir (19), drum roller (20) for spreading harden¬ ing liquid (21) and said drag means (17) are combined into a single unit that can be lifted and lowered re¬ lative to machine body (1 ) .

8. A machine as set forth in any of claims 2-7 , c h a r a c t e r i z e d in that said drag means (17) is provided with two or more drag planks (22) in synchronized grinding motion relative to each other.

9. A machine as set forth in any of claims 2-9,^' c h a r a c t e r i z e d in that the compression load of drag planks (22) on the casting surface is adjust¬ able.