US3623708A

US3623708A - System and means for selectively mixing concrete and incorporating dry additives therein

Info

Publication number: US3623708A
Application number: US811828A
Authority: US
Inventors: Robert C Futty; John L Kugle
Original assignee: IRL DAFFIN ASSOCIATES
Current assignee: IRL DAFFIN ASSOCIATES; IRL DAFFIN ASSOCIATES Inc; Barber Greene Co; C S JOHNSON Co
Priority date: 1969-04-01
Filing date: 1969-04-01
Publication date: 1971-11-30
Anticipated expiration: 1988-11-30

Abstract

A novel system and means for selectively mixing concrete and incorporating dry additives therein is disclosed. The basic raw materials for the concrete itself are supplied, in dry form, from a truck into an auxiliary mixing trough associated with the truck. Dry, solid additives, preferably in granular form, although finer modulus material may also be used, are then incorporated into the concrete batch being prepared in the mixing trough for the purposes of imparting antifreeze, water-reduction, and/or coloring properties to the selected batch. A novel apparatus is utilized for delivering the dry additives to the concrete batch, the novel apparatus incorporating a hopper assembly into which the dry additives are placed. The hopper assembly contains a unique mixing agitator means for mixing and breaking up the dry additive ingredients. Disposed below the mixing agitator means is a controlled feed means which selectively controls the amount of dry additives passed out from the hopper into a lateral conveyor means which preferably comprises an enclosed, auger arrangement. The dry additives, in selective and controlled portions, are conveyed by the auger arrangement into the auxiliary mixing trough whereupon such dry additives are incorporated into the concrete batch.

Description

United States Patent [72] Inventors Robert C. Putty Willow Street; John L. Kugle, Lancaster, both of Pa.

[211 App]. No. 811,828

[22] Filed Apr. 1, 1969 [45] Patented Nov. 30, 1971 [73] Assignee IRL Daflin Associates, Incorporated Lancaster, Pa.

[54] SYSTEM AND MEANS FOR SELECTIVELY MIXING CONCRETE AND INCORPORATING DRY ADDITIVES TI-IEREIN 17 Claims, 6 Drawing Figs.

52 US. Cl 259/164,

259/148 [51] Int. Cl. B28c 7/04 [50] Field 01 Search 259/164. 148,153,161,162.l69,170,172,178;222/136, 139, 142

[56] References Cited UNITED STATES PATENTS 742,591 10/1903 Clark 222/142 1,038,698 9/1912 Whitney et a1 259/ 164 2,649,289 8/1953 Giberson 259/170 X 2,778,535 1/1957 Seltzer 222/139 2,976,025 3/1961 Pro 259/178 X Primary Examiner-James Kee Chi Allorneys-Holman & Stern and Samuel L. Davidson ABSTRACT: A novel system and means for selectively mixing concrete and incorporating dry additives therein is disclosed. The basic raw materials for the concrete itself are supplied, in dry form, from a truck into an auxiliary mixing trough associated with the truck. Dry, solid additives, preferably in granular form, although finer modulus material may also be used. are then incorporated into the concrete batch being prepared in the mixing trough for the purposes of imparting antifreeze, water-reduction. and/or coloring'properties to the selected batch. A novel apparatus is utilized for delivering the dry additives to the concrete batch, the novel apparatus incorporating a hopper assembly into which the dry additives are placed. The hopper assembly contains a unique mixing agitator means for mixing and breaking up the dry additive ingredients. Disposed below the mixing agitator means is a controlled feed means which selectively controls the amount of dry additives passed out from the hopper into a lateral conveyor means which preferably comprises an enclosed, auger arrangement. The dry additives. in selective and controlled portions, are conveyed by the auger arrangement into the auxiliary mixing trough whereupon such dry additives are incorporated into the concrete batch.

PATENTEHnnvsonn 3.623.708

SHEET 1 [)F 4 INVENTORS FIG. 5 ROBERT c. FUTTY JOHN L. KUGLE BY (WW ATTORNEYS PATENTEDNUVSOISYI 3,623,708

sum 2 [IF 4 INVIIN'IOHS ROBERT C. FUTTY JOHN L. KUGLE M d/Ma ATTORNEYS PATENTEDNUVBOISYI 34623708 SHEET3UF4 mvsmons ROBERT C. FUTTY JOHN L. KUGLE BY {j ATTORNEYS SYSTEM AND MEANS F OR SELECTIVELY MIXING CONCRETE AND TNCORPORATTNG DRY ADDXTTVES THEREIN The subject invention generally relates to concrete mixing equipment of the type disclosed in U.S. Pat. No. 3,310,293, assigned to the assignee of the present invention, and is specifically concerned with the provision of a means associated with such equipment to permit dry, granular additives of various types to be easily incorporated with the other concrete ingredients in such mixing equipment.

As background of the instant invention, it should be appreciated that conventional concrete mixing equipment and techniques generally rely upon the use of so-called readymix" trucks incorporating a rotatable mixing drum into which all the required ingredients, including water, are introduced, prior to departure of the "ready-mix" truck from its base of operation. The rotation of the mixing drum is continued until the entire contents thereof have been delivered, regardless of the number of partial load deliveries that must be made by the concrete mix truck or the time elapsed before making a single delivery of its entire contents.

One major disadvantage of such conventional equipment and specifically the ready-mix" truck resides in the impossibility of selectively adding ingredients only to portions of a truckload since, of course, all adding operations are perfonned at an initial loading station. Additionally, the so-called ready-mix" trucks are not at all equipped to provide for the incorporation of antifreeze ingredients, water-reducing chemicals, or coloring materials to the concrete mix in predetermined, controlled portions.

A further disadvantage of such prior art conventional equipment resides in its inherent inability to deliver only partial loads of concrete to individual users when each user requires concrete having differing characteristics. ln such instances, the ready-mix" trucks must first return to their base of operation for the rotary drum thereon to be supplied with a different batch of ingredients capable of providing a concrete mix of the desired composition for each particular small user.

Many of the disadvantages discussed above have been obviated by the concrete mixing equipment of the type disclosed in prior U.S. Pat. No. 3,310,293 which primarily is directed to the provision of a concrete truck in which the basic ingredients of the concrete are stored in dry form and wherein individual controlled batches of concrete are mixed at the users location. Still, even with such improved concrete mixing equipment, no provisions were made for the incorporation of certain additives into the individual batches of concrete since the concrete truck involved normally would carry only the basic ingredients for a conventional concrete mix.

The prior art developed still further as evidenced by the auxiliary and associated concrete mixing equipment depicted in U.S. Pat. No. 3,336,01 1, also assigned to the assignee of the present invention. By virtue of the associated concrete equipment disclosed in this patent, it was possible, for the first time, to provide concrete mixing and delivery equipment which enabled selective small batch operations at the user's location, such operations providing the advantageous feature of being able to selectively change not only the concrete ingredient proportions but also the concrete additive proportions at will to satisfy the requirements of an individual, small batch user. Such equipment as disclosed in U.S. Pat. No. 3,336,011 is limited in operation, however, to the incorporation of liquid additives into a concrete batch.

With such prior accessory additive equipment designed for use with liquids only, rather complex liquid metering devices and liquid storage devices had to be provided. These metering and storage devices, of course, greatly increased the complexity and cost of the equipment involved and, in fact, posed problems in and of themselves. Completely enclosed storage tanks. for the additive liquids had to be provided and the danger of liquid spillage when filling such storage tanks was always present. Additionally, the storage tanks and metering devices themselves necessarily had to be constructed out of materials which would not be affected by the chemical action of the liquid additive. Further, since such equipment only operated to incorporate liquid additives into the concrete batch, the versatility of such system was limited to those additives which could be obtained or produced in liquid form.

With the above-discussed background of the prior art now firmly in mind, it should be appreciated that a need still exists for further auxiliary concrete equipment and specifically for an admixing device operative to incorporate dry additives rather than liquid additives into small, selected concrete batches at a user's location to thus provide a truly versatile and complete concrete system ofiering a full scope of additive choice. It is the primary object of the instant invention to provide a device which satisfies this need.

Other equally important objects of the instant invention are:

a. the provision of a means for incorporating dry additives in a concrete batch, which means operates in a selective and controlled manner;

b. the provision of a means for incorporating dry additives in a concrete batch, which means is simple in construction and operation;

c. the provision of a means for incorporating dry additives in a concrete batch, which means is entirely portable and may be utilized in association with many forms of concrete delivery equipment of the type dispensing dry, basic concrete ingredients;

d. the provision of a means for incorporating dry additives in a small concrete batch, which means is capable of storing the dry additive ingredients;

e. the provision of a means for incorporating dry additives in a concrete batch, which means operates to agitate and break up the dry additives stored therein; and,

. the provision of a means for selectively incorporating dry additives in a small concrete batch, which means operates from motive power tapped from a concrete truck with which such means are associated.

The above objects as well as other objects and advantages of the instant invention are implemented by the provision of an auxiliary admixing device operative in association with a concrete truck preferably of the type dispensing basic, dry concrete ingredients to be externally mixed in small batches, the auxiliary admixing device being operative to store, agitate, mix and feed dry additives placed therein and deliver such dry additives to the external concrete mixing equipment so as to alter the characteristics of the small batch of concrete being mixed therein.

The auxiliary admixing device is contemplated to comprise a hopper assembly removably attached to the concrete ingredient dispensing truck, the hopper assembly accepting and storing a given quantity of dry concrete additive ingredients. The hopper assembly contains a mixing agitator means operative to agitate and mix the dry additive ingredients placed in the hopper assembly and to break up such dry ingredients into a granular form. A feeding agitator means is also provided within the hopper assembly below the mixing agitator means and serves to selectively feed predetennined amounts of the dry concrete additives from the hopper assembly for subsequent transfer to the small concrete batch being mixed. Associated with the feeding agitator means is a controllable gate or slide assembly utilized for altering the size of the dispensing openings from the hopper assembly beneath the feeding agitator means.

The dry concrete ingredients are thus selectively passed from the hopper assembly in predetermined and controlled portions and amounts and are then laterally conveyed by a lateral conveyor means, preferably comprising an auger arrangement, to the location whereat mixing of the selected, small concrete batches is taking place. Of importance, from a convenience standpoint, is the fact that the mixing agitator means, feeding agitator means, and the auger arrangement comprising the lateral conveyor means are all contemplated to be driven through a clutch mechanism from a source of motive power taken from the concrete truck itself.

The invention will be better understood and additional objects and features thereof will become readily apparent from the following detailed description of a preferred inventive embodiment, such description referring to the appended drawings, wherein:

FIG. 1 is a schematic elevational view of the rear of a concrete truck incorporating the auxiliary admixing device of the instant invention;

FIG. 2 is a perspective illustration, partially in section and in phantom line for illustrative clarity, of the novel auxiliary admixing device of the instant invention;

FIG. 3 is a side, elevational view, partially in section, of the inventive device taken along lines 3-3 of FIG. 1;

FIG. 4 is an elevational illustration in section, of the inventive admixing device taken along lines 4-4 of FIG. 3 depicting the internal agitator means, control feed means, and conveyor means thereof;

FIG. 5 is an elevational illustration, partially broken away for clarity, of specific portions of the control feed means of the inventive auxiliary admixing device; and,

FIG. 6 is a side elevational view, broken away and in section, of the control feed means taken along lines 6-6 of FIG. 5.

Referring now to the drawings and particularly to FIGS. I and 2 thereof, the overall selective concrete mixing system and the particular preferred placement of the novel admixing apparatus or device on a concrete truck is disclosed. The concrete truck generally designated 2 is preferably of the type shown in detail in U.S. Pat. No. 3,310,293, assigned to the assignee of the present invention, and differs from prior art, conventional concrete trucks in that the basic ingredients of a concrete mix are stored in dry form in various separate compartments or

enclosures

4, 6 and 8, used for stone or gravel, sand, and cement, respectively. An internal dispensing means, not illustrated, is provided within the concrete truck for delivering controlled portions of stone and sand from

compartments

4 and 6, respectively, onto a driven conveyor mechanism 10.

The conveyor mechanism itself preferably is powered from an external, nonillustrated power takeoff associated with the concrete truck. Conveyor 10 is provided with an end support roller 12 having an extending axial shaft 14 upon which a chain sprocket gear 16 is mounted. A chain 18 is driven by the chain sprocket gear 16, and in turn, serves to drive a sprocket gear 20 disposed upon an axial shaft 22 which rotates a paddle-wheel metering or dispensing assembly 24 disposed above the conveyor 10 near the end thereof.

The paddle-wheel metering or dispensing assembly 24 serves to deliver metered amounts of cement from compartment 8 of the concrete truck to the stone and sand already present on the conveyor 10. The entire concrete ingredients of stone, sand, and cement are conveyed by conveyor mechanism 10 into an auxiliary mixing trough generally designated 26 having a rotating auger 28 therein. Water is added at this point to the mixture of dry ingredients and the resultant actual concrete mix in a ready to use" state is taken from an outlet 30 of the mixing trough. As should be appreciated, individual batches of concrete, each having specified and predetermined characteristics, can be produced in a simple and controlled manner at the users location by merely varying the proportional amounts of the individual, basic ingredients. A detailed description of the concrete truck and its associated components appears in U.S. Pat. No. 3,310,293, referred to previously.

An admixing apparatus or means generally designated 32 is adapted to be removably disposed to one side of the back of concrete truck 2 by clamping means 34 (FIG. 3) preferably attached to angle iron support members 36 or the like welded or bolted to the truck body. The admixing means 32 has the function of dispensing controlled portions and amounts of dry concrete additives into the auxiliary mixing trough 26, thus into the individual concrete batch being mixed therein. The dry additives are preferably in granular form and,are incorporated into the concrete batch being prepared in the mixing trough for the purpose of imparting controlled antifreeze, water-reduction, and/or coloring properties thereto. Various known ingredients can be used for this purpose.

The admixing means is seen to comprise a hopper assembly means or arrangement 38'for storing dry concrete additives for subsequent incorporation into the concrete ingredients within the mixing trough 26. A cover assembly 40 is provided on the hopper means 38 such that the dry additives can be placed therein. The lower portion of the hopper assembly means 38, as best seen in FIG. 3, preferably comprises an inner or top compartment 42 and an outer or bottom compartment 44. Agitator means 46 is disposed within the inner compartment 42 of the hopper assembly means and serves to agitate and mix the stored dry concrete additives. Agitator means 46, as best seen in FIG. 4, comprises an elongated shaft 48 joumaled for rotation in the walls of the hopper assembly means, the shaft containing a plurality of outwardly extending fingers 50 thereon. Operation of the agitator means 46 further serves to break up any chunks of dry additive ingredients into a generally granular form.

A controlled feed means generally designated 52 is also provided within the inner compartment 42 of the hopper assembly means and is disposed below agitator means 46. The controlled feed means 52 serves to selectively, and in a controllable fashion, dispense predetermined portions and amounts of the dry concrete additives from the hopper assembly means. The controlled feed means comprises a feeding agitator means generally designated 54 and a cover slide means generally designated 56, the feeding agitator means and the cover slide means being disposed adjacent to opposite sides of a plurality of apertures 58 through the bottom of the inner compartment 42 which communicate with the outer compartment 44.

Cover slide means 56 extends outside and entirely across the bottom of the inner compartment of the hopper assembly means and preferably comprises an elongated, slidable plate 62 having a plurality of apertures 60 therein in a predetermined arrangement as can best be seen from FIGS. 5 and 6. Displacing the cover slide means 56 in the lateral direction causes a change in the degree of registration of the apertures 60 therein with respect to the apertures 58 in the bottom of the inner compartment. In other words, lateral displacement of the cover slide means serves to increase or decrease the effective opening area between the inner and outer compartments of the hopper assembly means.

The lateral positioning of the cover slide means 56 is effected through operation of a control feed regulator level 68 pivotally mounted by a bolt 70 to the walls of the outer compartment 44 of the hopper assembly means 38. A shaft 72, as shown in FIG. 6, extends from one end of the control feed regulator lever 68 to the elongated plate 62 of the cover slide means 56. The control feed regulator lever 68 can be maintained in any desired angular position thus effecting any desired effective aperture opening by means of a lock wingnut 74 disposed in a slotted bracket 76 of the hopper assembly. Lateral displacement of the cover slide means 56 is undertaken against the force of a return spring means generally designated 78.

The feeding agitator means 54 disposed immediately above the apertures at the bottom of the inner compartment comprises an axial shaft 64, also journalled for rotation in the walls of the hopper assembly, the shaft 64 carrying a scallopped paddle wheel assembly 66. Rotation of the feeding agitator means 54 serves to feed the dry concrete additives in the hopper assembly to the plurality of apertures 58 in the bottom thereof and, in cooperation with the cover slide means 56 which controls the effective area of the aperture openings within the hopper assembly, functions to meter the dispensing rate of the concrete additives from the hopper assembly in a predetermined, controlled fashion.

Disposed directly beneath the apertures 58 and in the outer compartment 44 of the hopper assembly is a conveyor or transport generally designated 80, as can best be seen from FIG. 4. Conveyor means 80 serves the function of conveying the controlled, predetermined portions of dry concrete additives dispensed by the control feed means 62 to the location of the concrete batch in the mixing trough 26, the dry concrete additives being transported in a generally lateral direction. Conveyor means 80 preferably comprises an auger arrangement 82 disposed within a tubular housing 84, as illustrated. The auger arrangement 82 includes an extending axial shaft 86, as shown. At the end of the tubular housing 84, an opening 88 is provided, the opening preferably being positioned just above the auxiliary mixing trough 26 of the concrete truck 2.

A drive means is provided for simultaneously driving and thus rotating the agitator means 46, the feeding agitator means 54, and the conveyor or transport means 80. initially, it should be noted that the respective

axial shafts

48, 64 and 86 of both agitator means and the auger arrangement are coupled together for simultaneous rotation by a chain and sprocket assembly generally designated 90 disposed within a guard housing 92. Axial shaft 86 for the auger arrangement 82 is coupled to a separate elongated shaft 94 having a drive gear 96 thereon, the elongated shaft 94 being joumalled for rotation between a clutch means generally designated 98 having a control handle 100 and the chain and sprocket assembly 90. lnput power to clutch means 98 is taken directly from a gear 102 provided on the extending axial shaft 14 of the end support roller 12 of conveyor by means of a chain drive 104 and sprocket wheel 106, as illustrated in FIG. 2.

Having the structural configuration of the inventive admixing device now firmly in mind, the operation thereof can now be briefly summarized. First, let it be assumed that the concrete truck 2 has arrived at the field location of the user and a selected batch of concrete comprising predetermined portions of the various concrete ingredients is being transported by the conveyor means 10 of the concrete truck to the auxiliary mixing trough 26. Depending upon particular conditions existing at the user's location and further depending upon the user's own needs, certain additives may be desirable or necessary to be incorporated into the concrete batch. Presumably, these dry additives have previously been stored in the hopper assembly means 58 of the admixing device 32.

The operator of the concrete truck would first position and adjust the control feed regulator lever 68 to some predetermined angular position bringing about a given effective aperture opening area through the bottom of the inner compartment of the hopper assembly, this opening area being associated with a desired dry additive feed rate. The operator then would grasp clutch control handle 100 engaging the clutch means 98. Now, the elongated shaft 94 would be caused to rotate through the agency of the sprocket wheel or gear 102 on the driven conveyor 10, the chain 104, and the wheel or gear 106. Rotation of elongated shaft 94 causes simultaneous rotation of the agitator means 46, the feed agitator means 54, and the transport or conveying means 80 comprising the auger arrangement 82 by means of the sprocket and chain assembly 90.

Operation of the agitator means 46 serves to agitate, break up, and mix the dry additive ingredients in the hopper assembly 38. Rotation of the feed agitator means 54 feeds the granular, dry additives toward the apertures 58 in the bottom of the inner compartment of the hopper assembly means, the dry additives then being dispensed at a controlled rate from the hopper assembly means into the auger arrangement 82. Rotation of the auger arrangement 82 serves to transport and convey, in a lateral direction, the dispensed dry additives towards the opening 88 in the housing 84. The dry additives, at this position, would drop into the mixing trough 26 and be incorporated into the dry concrete ingredients therein delivered by the truck conveyor 10. Water would then be added to the mixing trough and, by virtue of rotation of the auger assembly 28, a select batch of concrete would be mixed and dispensed at the opening 30. This select concrete batch would have the desired predetermined characteristics.

As should now be apparent, the objects initially set forth at the outset of this specification have been successfully achieved. Accordingly,

What is claimed is:

1. An apparatus for dispensing dry additives to a remote location, said apparatus comprising: hopper assembly means for storing the dry additives; agitator means disposed within said hopper assembly means for agitating and mixing the dry additives; controlled feed means associated with said hopper assembly means for selectively and controllably dispensing predetermined portions of the dry additives from said hopper assembly means, said controlled feed means comprising a plurality of apertures at the bottom portion of said hopper assembly means and a feeding agitator means disposed in said hopper assembly means adjacent said plurality of apertures for feeding the additives to said plurality of apertures; and conveyor means for conveying the dispensed predetermined portions of the dry additives to a remote location, said conveyor means being disposed beneath said hopper assembly means and conveying the dry additives in a substantially lateral direction to the remote location.

2. A concrete mixing system comprising in combination; truck means incorporating a plurality of compartments therein for the separate storage of dry, basic concrete ingredients, selective dispensing means for dispensing predetermined quantities of each of the dry, basic concrete ingredients from said plurality of compartments, and driven conveyor means for transporting the dispensed ingredients from said truck means; mixing trough means disposed externally of said truck means for receiving the dispensed ingredients from said conveyor means, watering the ingredients, and mixing the ingredients; and admixing means removably disposed on said truck means for dispensing controlled portions of dry concrete additives into said mixing trough means wherein the dry additives are incorporated into the concrete batch in said mixing trough means, said admixing means comprising hopper assembly means for storing the dry concrete additives, agitator means disposed within said hopper assembly means for agitating and mixing the dry concrete additives, controlled feed means associated with said hopper assembly means for selectively and controllably dispensing predetermined portions of the dry concrete additives from said hopper assembly means, and transport means for conveying the dispensed predetermined portions of the dry concrete additives to said mixing trough means, whereby the additives are incorporated therein.

3. An apparatus as defined in claim 1, further including mounting means for removably mounting said apparatus on a concrete truck.

4. An apparatus as defined in claim 1, wherein said controlled feed means further comprises cover slide means disposed on the outside of said hopper assembly means at the bottom portion thereof over said plurality of apertures, said cover slide means having apertures therein in a predetermined arrangement.

5. An apparatus as defined in claim 4, further including adjustable positioning means for positioning said cover slide means such that at least some of said apertures therein communicate with said plurality of apertures of said hopper assembly means.

6. An apparatus as defined in claim 5, wherein said conveyor means comprises an auger arrangement.

7. An apparatus as defined in claim 6, further including drive means for simultaneously driving said agitator means, and said auger arrangement.

8. An apparatus as defined in claim 7, wherein said drive means further comprises transmission means including a clutch for coupling said drive means to a motive power source on a concrete truck.

9. A system as defined in claim 2, wherein said admixing means further includes mounting means for removably mounting said admixing means on said truck means.

10. A system as defined in claim 9, wherein said hopper as-' sembly means includes a plurality of apertures at the bottom portion thereof and wherein said controlled feed means comprises a feeding agitator means disposed in said hopper assembly means adjacent said plurality of apertures for feeding the concrete additives to said plurality of apertures.

l l. A system as defined in claim 10, wherein said controlled feed means further comprises cover slide means disposed on the outside of said hopper assembly means at the bottom portion thereof over said plurality of apertures, said cover slide means having apertures therein in a predetermined arrangement.

12. A system as defined in claim ll, wherein said admixing means further includes adjustable positioning means for positioning said cover slide means such that at least some of said apertures therein communicate with said plurality of apertures of said hopper assembly means. v

13. A system as defined in claim 12, wherein said transport means is disposed beneath said hopper assembly means and conveys the concrete additives dispensed from said hopper assembly means in a substantially lateral direction to said mixing trough means.

14. A system as defined in claim 13, wherein said transport means comprises an auger arrangement.

15. A system as defined in claim 14, wherein said admixing means further includes drive means for simultaneously driving said agitator means, said feeding agitator means, and saidauger arrangement.

16. A system as defined in claim 15, wherein said drive means further comprises transmission means including a clutch for coupling said drive means to said driven conveyor means of said truck means, whereby, when said clutch is engaged, said driven conveyor means comprises a motive power source for said drive means of said admixing means.

17. A system as defined in claim 16, wherein said drive means comprises a sprocket and chain arrangement disposed externally of said hopper assembly means for coupling said agitator means, said feeding agitator means, and said auger arrangement together for simultaneous rotation, an elongated shaft joumalled for rotation coupled between said clutch and said sprocket and chain arrangement, and sprocket and chain means provided between said driven conveyor on said truck means and said clutch.

Claims

10. A system as defined in claim 9, wherein said hopper assembly means includes a plurality of apertures at the bottom portion thereof and wherein said controlled feed means comprises a feeding agitator means disposed in said hopper assembly means adjacent said plurality of apertures for feeding the concrete additives to said plurality of apertures.

11. A system as defined in claim 10, wherein said controlled feed means further comprises cover slide means disposed on the outside of said hopper assembly means at the bottom portion thereof over said plurality of apertures, said cover slide means having apertures therein in a predetermined arrangement.

12. A system as defined in claim 11, wherein said admixing means further includes adjustable positioning means for positioning said cover slide means such that at least some of said apertures therein communicate with said plurality of apertures of said hopper assembly means.

15. A system as defined in claim 14, wherein said admixing means further includes drive means for simultaneously driving said agitator means, said feeding agitator means, and said auger arrangement.

17. A system as defined in claim 16, wherein said drive means comprises a sprocket and chain arrangement disposed externally of said hopper assembly means for coupling said agitator means, said feeding agitator means, and said auger arrangement together for simultaneous rotation, an elongated shaft journalled for rotation coupled between said clutch and said sprocket and chain arrangement, and sprocket and chain means provided between said driven conveyor on said truck means and said clutch.