MIX CONSTRUCTION MATERIAL

TECHNICAL FIELD

The present invention relates to a method of producing raw materials for use in producing a dry mix construction material and a system thereof.

BACKGROUND ART

Typically, manufacturing/production of the dry mix construction material such as concrete and the ancillary concrete materials such as plaster, mortar, cement reinforced sawdust materials, etc., (hereinafter collectively referred to as "DMC") used for any infrastructure development project, include mixing of various materials such as hydraulic material(s), coarse aggregates, fine aggregates, additive(s), and/or pozzolonic material(s). To obtain a DMC of specific property or design requirement, different raw materials having different properties/characteristics are selected and mixed in appropriate amounts/weights. If the amounts/weights of the materials are not appropriate, the resulting DMC will cause failures in the developed infrastructure. Typically, all the raw materials are delivered to a construction site where the materials are mixed together to form the DMC. There are various methods through which the raw materials are delivered to the construction site.

In one method, pre-measured sacks of cement and aggregate are delivered to the construction site, where the sack is opened and mixed to form the DMC. However, such method is expensive and labor intensive. In addition, there is no indication of how much quantity of the cement and aggregate is to be added to form the DMC. Further, the resulting DMC may or may not be of desired quality or parameters as the mixing of raw materials is largely dependent upon the experience of a contractor at the construction site.

In another method, delivery trucks or portable concrete plants are used to transport required amounts of raw materials to the construction site and prepare the DMC at the construction site. These delivery trucks or portable concrete plants include compartments to separately store the raw materials and/or a mixture of raw materials such as a mixture of fine aggregate and coarse aggregate. The raw materials and/or the mixture is weighed and loaded onto the delivery trucks or portable concrete plants at a plant. The delivery trucks or portable concrete plants further include mixers to mix the raw materials and form DMC. The delivery trucks or portable concrete plants further include conveyors to transport the raw materials from the compartments to the mixer and from the mixer to a particular location at the construction site. However, such delivery trucks or portable concrete plants are bulky and expensive.

In addition, these solutions do not give flexibility in selecting individual raw materials itself for producing the DMC. Thus, there is a need for a solution that overcomes these deficiencies.

SUMMARY

In accordance with the purposes of the invention, the present invention as embodied and broadly described herein, relates to a method for producing raw materials for use in producing a dry mix construction material (DMC) and a system thereof.

Accordingly, a coarse aggregate having a mode average particle diameter (Dl) in a predetermined range is obtained. A fine aggregate having a mode average particle diameter (D2) in range of 1/3 to 1/5 of the mode average particle diameter (Dl) of the coarse aggregate is then obtained. A load of the coarse aggregate is then weighed such that an amount (Wl) of the coarse aggregate is in a range of 25 to 50 weight percentage of the DMC. A load of the fine aggregate is then weighed such that an amount (W2) of the fine aggregate is in a range of 25 to 42 weight percentage of the DMC. Thereafter, the weighed amount (Wl) of the coarse aggregate and the weighed amount (W2) of the fine aggregate are mixed to obtain a first mixture for use in producing the DMC. The first mixture is stored in a first packaging container. Thereafter, corresponding loads of hydraulic material, additive material, and/or pozzolonic material required to produce the DMC are weighed. Upon weighing, the weighed amounts of the hydraulic material, additive material, and/or pozzolonic material are either individually or in combination with each other are stored in further packaging container for use in producing the DMC.

The advantages of the present invention include, but are not limited to, weighing and packing individual materials separately prior to transporting to a construction site. This enables the resultant DMC to be of desired quality and parameters. In addition, flexibility is provided to the user to select and pack either individual materials or mixture of materials. BRIEF DESCRIPTION OF THE DRAWINGS

The advantages and features of the present invention will become better understood with reference to the following detailed description taken in conjunction with the accompanying drawings, in which: Figure 1 illustrates an example system for producing raw materials used in producing dry mix construction material (DMC), according to an embodiment of the present invention.

Figures 2 to 9 illustrate example flowcharts indicating methods for producing raw materials used in producing dry mix construction material (DMC), according to the embodiment of the present invention.

Like reference numerals refer to like parts throughout the description of several views of the drawing.

DESCRIPTION OF THE INVENTION

The exemplary embodiments described herein detail for illustrative purposes are subjected to many variations. It should be emphasized, however, that the present invention is not limited to a method for producing raw materials for producing dry mix construction material (DMC) and a system thereof. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but these are intended to cover the application or implementation without departing from the spirit or scope of the present invention.

Unless otherwise specified, the terms, which are used in the specification and claims, have the meanings commonly used in the field of construction and/or construction material production process and machines involved therein. Specifically, the following terms have the meanings indicated below.

The terms "a" and "an" herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.

The terms "having", "comprising", "including", and variations thereof signify the presence of a component.

The term "ash" or "fly ash" refers here to coal combustion products that are generated as industrial wastes in coal-fired thermal power stations.

The terms "Site Mix Construction", "Ready Mix Construction" and "Dry Mix Construction" are interchangeably referred to hereinafter as "SMC", "RMC" and "DMC" respectively.

The term "dry mix construction materials" refers here to the construction materials used for various construction purposes such as construction for building structure construction, construction for road and runway pavement, construction for building dams and flyovers, and/or construction for building underground and underwater structures and includes materials such as dry mix concrete, and ancillary concrete materials such as plaster, mortar and/or cement reinforced saw dust materials.

The term "ancillary construction materials" refers here to the plaster materials, mortar, repairing cement admixture, and/or reinforced cement admixtures.

The term "hydraulic material(s)" refers to cement which are capable of setting and hardening under water.

The term "pozzolanic material(s)" refers to a siliceous or siliceous and aluminous material, which in itself possesses little or no cementing property, but will in a finely divided form - and in the presence of moisture - chemically react with calcium hydroxide at ordinary temperatures to form compounds possessing cementitious properties.

The term "powder based additive(s)" refers to synthetic or natural occurring materials or compounds or agents which are capable of improving the physical and chemical properties of the dry mix construction and ancillary construction materials.

The industrial waste referred to herein include but not limited to the industrial wastes from thermal power plants or cool burning units, mining industry, blast furnace slag.

Figure 1 illustrates an example system 100 for implementing a method for producing raw materials for use in producing a dry mix construction material (DMC), according to an embodiment of the present invention. Examples of the dry mix construction material include concrete and ancillary concrete materials such as plaster, mortar, cement reinforced sawdust materials, etc. The system 100 is a networked manufacturing plant that produces raw materials for use in producing the DMC. The system 100 includes a plurality of material storage units (MSUs), MSU 101-1, 101-2 ... 101-5 (hereinafter plurality of material storage units shall be referred to as MSUs 101 and each individual material storage unit shall be referred to as MSU 101-1, MSU 101-2, ... etc.,) that store raw materials required for producing the DMC. The raw materials include hydraulic material(s), fine aggregate(s), coarse aggregate(s), additive material(s), and optional pozzolanic material(s).

As would be understood, size of coarse aggregates depends upon a required strength of the DMC. In general, for strength up-to 200 kg/cm2, aggregates up-to 40 millimeters (mm) may be used; and for strength above 300 kg/cm2 aggregate up-to 20 mm may be used. Typically, graded aggregates are desirable for making DMC as the space between larger particles is effectively filled by smaller particles to produce a high-degree of particle packing structure. In one example, the graded aggregates can be 'continuous' aggregate (also known as 'well-graded' or 'combined' aggregate), wherein the aggregate includes particles of a wide range of sizes. In another example, the graded aggregates can be 'gap- graded' aggregate, wherein the aggregate lacks one or more intermediate size. As such, MSU 101-1 corresponds to a coarse aggregate mixture comprising at least two types of coarse aggregates based on their normal maximum size or mode average particle diameter and gradation. In one example, the mixture can be a graded 20 mm down sized combined coarse aggregate obtained by blending a 20 mm down sized single size coarse aggregate with a 12.5 mm downsized graded coarse aggregate. The at least two types of coarse aggregates are separately procured and stored in separate sub-storage units within the MSU 101-1. The at least two types of coarse aggregates are never intermixed within the MSU 101-1. The coarse aggregate is at least one of processed crushed stone, processed gravel, and processed blue metal. Further, the coarse aggregate is substantially devoid of moisture content, i.e., in a bone-dry condition, but not hot. The coarse aggregates are treated using techniques as known in the art so that the coarse aggregates are substantially devoid of moisture content.

Further, each of the remaining raw materials is graded and grouped based on various grouping parameters/characteristics. The parameters/characteristics can be particle size distribution (PSD), chemical properties, and physical properties. Accordingly, the fine aggregates are grouped based on PSD. Such grouping may be performed, prior to the storing, by using techniques as known in the art. As such, MSU 101-2 includes various sub- storage units corresponding to each of the groups of fine aggregates. The fine aggregate is processed sand. The fine aggregate is substantially devoid of moisture content, i.e., in a bone-dry condition, but not hot. The fine aggregates are treated using techniques as known in the art so that the fine aggregates are substantially devoid of moisture content.

The hydraulic materials are grouped based on (a) chemical properties of hydraulic materials, (b) physical properties of hydraulic materials, and (c) particle size distribution (PSD) of hydraulic materials. Such grouping may be performed, prior to the storing, by using techniques as known in the art. Examples of the hydraulic materials include ordinary cement, Portland cement, limestone fines, and silica fume. In addition to the grouping parameters, the grouping may further be based on supplier, cost, specific gravity, class, and, grade. As such, MSU 101-3 includes various sub-storage units corresponding to each of the groups of hydraulic materials.

The powder based additives (or interchangeably referred to as powder based admixtures or additive materials) are grouped based on chemical properties of the additive materials. Examples of such grouping can be Set-Retarding additives; Air entrainment additives; Water-reducing additives; Accelerating concrete admixtures; Shrinkage reducing concrete admixtures; super-plasticizers; and Corrosion-inhibiting admixtures. Such grouping may be performed, prior to the storing, by using techniques as known in the art. Examples of the additive materials include cellulosic material, starch material, lignosulphonate salts, hydrocarbolic acid salts, stearate salt of alkali metal group or alkaline earth metal group, Sulphonated Melamine Formaldehyde, Sulphonated Naphthalene Formaldehyde, Poly Carboxylic Ether, salts of nitrate, salts of nitrite, salts of formate, salts of thiocyanate, Calcium Ligno-sulphonates, Carbohydrates derivatives, fatty acid salts or vinsol resin, hydroxide salt of alkali metal group or alkaline earth metal group and the like. As such, MSU 101-4 includes various sub-storage units corresponding to each of the groups of additive materials.

The pozzolanic materials are grouped based on (a) particle size distribution (PSD) of the pozzolanic material, (b) mechanical properties of the pozzolanic material, and (c) chemical properties of the pozzolanic material. Such grouping may be performed, prior to the storing, by using techniques as known in the art. Examples of the hydraulic materials include fly ash, ground granulated blastfurnace slag (GGBS), volcanic ash, finely ground quartz, mechanically modified fly ash, mechanically modified pond ash, chemically modified fly ash, and chemically modified pond ash. As such, MSU 101-5 includes various sub-storage units corresponding to each of the groups of pozzolanic materials.

The system 100 further includes at least one selection unit 102, at least one weighing unit 103, at least one mixing unit 104, and at least one packaging unit 105. The at least one selection unit 102 and the at least one weighing unit 103 are operatively coupled with the plurality of MSUs 101 via a plurality of conveyors (represented by solid arrows). The at least one weighing unit 103 is further operatively coupled with the at least one selection unit 102, the at least one mixing unit 104, and the at least one packaging unit 105 via a plurality of conveyors (represented by solid arrows). The at least one mixing unit 104 is further operatively coupled with the at least one packaging unit 105 via a plurality of conveyors (represented by solid arrows).

In accordance with the present invention, the at least one selection unit 102 is configured to obtain coarse aggregate having a mode average particle diameter (Dl) in a predetermined range. As such, based on the mode average particle diameter (Dl) and the predetermined range, the at least one selection unit 102 connects with a particular storage unit of the MSU 101-1 and obtains the coarse aggregate via the plurality of conveyors. Thereafter, the at least one selection unit 102 determines a mode average particle diameter (Dl) of the coarse aggregate through a PSD curve analysis interpretation. The at least one selection unit 102 then subjects the coarse aggregate to a mechanical modification process in a controlled manner until its mode average particle diameter (Dl) is in the predetermined range. As such, the at least one selection unit 102 may include necessary hardware and/or software module to perform PSD curve analysis and to perform mechanical modification process, as known in the art.

The at least one selection unit 102 is further configured to obtain a fine aggregate having a mode average particle diameter (D2) in range of 1/3 to 1/5 of the mode average particle diameter (Dl) of the coarse aggregate. As such, based on the mode average particle diameter (D2), the at least one selection unit 102 connects with a particular storage unit of the MSU 101-2 and obtains the fine aggregate via the plurality of conveyors. Thereafter, the at least one selection unit 102 determines a mode average particle diameter (D2) of the fine aggregate through a PSD curve analysis interpretation. The at least one selection unit 102 then subjects the fine aggregate to a mechanical modification process in a controlled manner until its mode average particle diameter (D2) is in the range of 1/3 to 1/5 of the mode average particle diameter (Dl) of the coarse aggregate.

The at least one selection unit 102 then delivers the selected coarse aggregates and fine aggregates to the at least one weighing unit 103 via the plurality of conveyors. The at least one weighing unit 103 is configured to weigh a load of the coarse aggregate such that an amount (Wl) of the coarse aggregate is in a range of 25 to 50 weight percentage (wt%) of the dry mix construction material. The at least one weighing unit 103 is configured to weigh a load of the fine aggregate such that an amount (W2) of the fine aggregate is in a range of 25 to 42 weight percentage (wt%) of the dry mix construction material. In an example, the DMC is to be produced having a total weight (i.e., dry weight without water) of approximately 2400 kg. In such example, the at least one weighing unit 103 weighs a load of the coarse aggregate such that the amount (Wl) is in the range from 600 kg to 1200 kg in the total weight of 2400 kg. Further, in the example, the at least one weighing unit 103 weighs a load of the fine aggregate such that the amount (W2) is in the range from 600 kg to 1000 kg in the total weight of 2400 kg.

Upon weighing, the at least one weighing unit 103 delivers the weighed amount (Wl) of the coarse aggregate and the weighed amount (W2) of the fine aggregate to the at least one mixing unit 104. In one implementation, there is only one selection unit and weighing unit present in the system 100 for selecting and weighing aggregates. In such implementation, the selection unit first selects coarse aggregates and the weighing unit then weighs the coarse aggregates and delivers to the at least one mixing unit 104. Thereafter, the selection unit selects fine aggregates and the weighing unit then weighs the fine aggregates and delivers to the at least one mixing unit 104. In another implementation, there are two separate selection unit and weighing unit present in the system 100 for individually selecting and weighing the coarse and fine aggregates.

The at least one mixing unit 104 is configured to mix the weighed amounts (Wl, W2) to obtain a first mixture for use in producing the DMC. The at least one mixing unit

104 can include hardware and/or software for mixing materials as known in the art. The at least one mixing unit 104 then delivers the first mixture to the at least one packaging unit 105. The at least one packaging unit 105 is configured to store the first mixture in a first packaging container. The at least one packaging unit 105 can include hardware and/or software for storing/packing materials as known in the art. The packaging container can be made of any suitable material capable of carrying a load of the first mixture. The packaging container can be of any shape. In one example, the total amount of the first mixture is stored/ packed in a single packaging container. In another example, the total amount of the first mixture can be segregated and stored/ packed in multiple packaging containers. In an implementation, the weighed amounts (Wl, W2) of the coarse and fine aggregates are printed on the packaging container. In one implementation, the weighed amounts (Wl, W2) of the coarse and fine aggregates are printed on a separate sheet and the separate sheet is provided separately with the packaging container. The first mixture thus formed is transferred to a silo (not shown in the figure) via a plurality of conveyors (not shown in the figure) for storage and/ or dispatching to a construction site. The at least one packaging unit

105 and the silo are operatively coupled with each other through the plurality of conveyors.

Further, the system 100 includes a control unit 106. The control unit 106 is communicatively coupled with the plurality of MSUs 101, the at least one selection unit 102 and the at least one weighing unit 103 over a communication network (represented by dashed arrows). The control unit 103 can be an electronic device capable of sending/receiving data over a communication network and receiving data via user-input. Examples of the control unit 103 include, but not limited to, server, personal desktop, laptop, tablet, notebook, personal digital assistant, and special purpose devices. Examples of the communication network include wired network and wireless network.

In operation, the control unit 106 receives a user-input indicative of producing the DMC. In one implementation, the user-input can indicate at least one of following:

• a total amount of DMC;

• a range for mode average particle diameter (Dl) of the coarse aggregate;

• amount (Wl) and weight percentage of the coarse aggregate;

• a range for mode average particle diameter (D2) of the fine aggregate; and

• amount (W2) and weight percentage of the fine aggregate;

• type of the hydraulic material;

• amount (W3) and weight percentage of the hydraulic material;

• type of the pozzolanic material;

• amount (W4) and weight percentage of the pozzolanic material;

• type of the additive material; and

• amount (W5) and weight percentage of the additive material.

In one implementation, the user-input can be indicative of initial design parameters of DMC such as application, strength, water content, amount, workability requirements, etc. In such implementation, the control unit 106 determines the aforementioned type and amount of raw materials required based on the initial design parameters of the DMC. The control unit 106 may fetch a pre-stored table indicative of mapping between properties of DMC and raw materials required from a database (not shown in the figure), and accordingly determine the aforementioned type and amount of raw materials required.

Based on the user-input, the control unit 106 may select a particular storage unit of the MSU 101-1 storing the coarse aggregate and may provide a signal to the at least one selection unit 102 to obtain the coarse aggregate from the particular storage unit of the MSU 101-1. Likewise, the control unit 106 may select MSU 101-2 storing the fine aggregate and provides a signal to the at least one selection unit 102 to obtain the fine aggregate from the particular storage unit of the MSU 101-2. In one implementation, the control unit 106 may select the particular storage unit based on an inventory of the aggregates stored in the MSUs from a memory (not shown in the figure). In one such implementation, the control unit 106 may receive data from one or more sensors coupled to each of the MSUs and update the inventory based on the data. Further, the control unit 106 may provide signal to the at least one weighing unit 103 to weigh the load of the coarse aggregates and the load of the fine aggregates in accordance with the user-input. As such, the at least one weighing unit 103 may include sensors (not shown in the figure) and gates (not shown in the figure). The gates are operated by actuating means (not shown in the figure). The sensors may monitor the weight of the load of the coarse aggregates and the load of the fine aggregates as being delivered by the at least one selection unit 102. When the desired amounts (Wl, W2) are weighed, the sensors may provide a signal to the actuating means to close the gates such that further amounts of coarse aggregates and fine aggregates are not delivered from the at least one selection unit 102 into the at least one weighing unit 103.

Further, in accordance with the present invention, upon creating the first mixture of coarse aggregate and fine aggregate, each of the remaining materials can be weighed and stored in packaging containers separate from the first packaging containers. This ensures that the coarse aggregate and fine aggregate remain completely separate from the remaining raw materials until mixed together to produce the DMC.

In one implementation, each of the remaining materials are individually weighed and stored in separate packaging containers. In such implementation, the control unit 106 may receive a further user-input indicative of storing the remaining materials separately. The control unit 106 may then provide signal to the at least one weighting unit 103 to directly fetch the individual raw materials from their corresponding storage units in the MSU 101 in accordance with the further user-input.

Further, as described above, the control unit 106 may provide signal to the at least one weighing unit 103 to weigh the load of the hydraulic material, the pozzolanic material, and the additive material in accordance with the user-input indicative of producing DMC. The control unit 106 may also provide signal to the at least one weighting unit 103 to directly deliver the weighed raw materials to the at least one packaging unit 105 for storing in further packaging containers. The further packaging containers can be made of any suitable material capable of carrying a load of the remaining raw materials. The further packaging containers can be of any shape.

Accordingly, the at least one weighing unit 103 weighs a load of hydraulic material such that an amount (W3) of the hydraulic material is in a range of 0 to 19 weight percentage (wt%) of the DMC. In the above example, the at least one weighing unit 103 weighs a load of the hydraulic material in the range from 0 kg to 450 kg in the total weight of 2400 kg. As would be understood, the hydraulic material alone cannot be used more than 450 kg per cubic meter due to hydration cracks related problem. Thereafter, the at least one weighing unit 103 directly delivers the weighed amount to the at least one packaging container 105. The at least one packaging unit 105 stores the weighed amount (W3) of the hydraulic material in a further packaging container for use in producing the dry mix construction material.

Thereafter, the at least one weighing unit 103 weighs a load of pozzolanic material such that an amount (W4) of the pozzolanic material is in a range of 0 to 23 weight percentage (wt%) of the dry mix construction material. In the above example, the at least one weighing unit 103 weighs a load of the pozzolanic material in the range from 0 kg to 550 kg in the total weight of 2400 kg. The at least one weighing unit 103 then directly delivers the weighed amount to the at least one packaging container 105. The at least one packaging unit 105 stores the weighed amount (W4) of the pozzolanic material in a further packaging container for use in producing the dry mix construction material.

Thereafter, the at least one weighing unit weighs a load of additive material such that an amount (W5) of the additive material is in a range of 1 to 5 weight percentage (wt%) of the dry mix construction material. The at least one weighing unit 103 then directly delivers the weighed amount to the at least one packaging container 105. The at least one packaging unit 105 stores the weighed amount (W5) of the additive material in a further packaging container for use in producing the dry mix construction material.

In one implementation, a set of two or more of the remaining materials can be individually weighed and mixed together to form a second mixture different from the first mixture. The second mixture is then stored in separate packaging containers. In such implementation, the control unit 106 may receive a further user-input indicative of mixing two or more materials together and storing the mixture separately from other remaining materials. The control unit 106 may then provide signal to the at least one weighting unit 103 to directly fetch the individual raw materials from their corresponding storage units in the MSU 101.

Further, as described above, the control unit 106 may provide signal to the at least one weighing unit 103 to weigh the load of the hydraulic material, the pozzolanic material, and the additive material in accordance with the user-input indicative of producing DMC. The control unit 106 may also provide signal to the at least one weighting unit 103 to first deliver the weighed raw materials to the at least one mixing unit 104 for mixing the materials into a second mixture, and then deliver the mixture to the at least one packaging unit 105 for storing in further packaging containers. The further packaging containers can be made of any suitable material capable of carrying a load of the second mixture. The further packaging containers can be of any shape.

Thus, in one example, two of the remaining raw materials can be mixed together and packed/stored separately. The last remaining raw material(s) can be packed individually as described above. In another example, all of the remaining materials are individually weighed, mixed together, and packed/stored. Accordingly, in one implementation, the at least one weighing unit 103 weighs a load of hydraulic material such that an amount (W3) of the hydraulic material is in a range of 0 to 19 weight percentage (wt%) of the dry mix construction material, as described earlier. Thereafter, the at least one weighing unit 103 weighs a load of pozzolanic material such that an amount (W4) of the pozzolanic material is in a range of 0 to 23 weight percentage (wt%) of the dry mix construction material, as described earlier.

Upon weighing, the at least one weighing unit 103 delivers the weighed amount

(W3) of the hydraulic material and the weighed amount (W4) of the pozzolanic material to the at least one mixing unit 104. The at least one mixing unit 104 mixes the weighed amount (W3) of the hydraulic material and the weighed amount (W4) of the pozzolanic material to obtain a further mixture. The at least one mixing unit 104 delivers the further mixture to the at least one packaging unit 105. The at least one packaging unit 105 then stores the further mixture in a further packaging container for use in producing the dry mix construction material. As such, the additive material is weighed and stored in a packaging container separate from the first packaging container comprising the first mixture and the further packaging container comprising the further mixture of hydraulic material and pozzolanic material, as described above.

In another implementation, the at least one weighing unit 103 weighs a load of hydraulic material such that an amount (W3) of the hydraulic material is in a range of 0 to 19 weight percentage (wt%) of the dry mix construction material, as described earlier. The at least one weighing unit 103 weighs a load of additive material such that an amount (W5) of the additive material is in a range of 1 to 5 weight percentage (wt%) of the dry mix construction material, as described earlier.

Upon weighing, the at least one weighing unit 103 delivers weighed amount (W3) of the hydraulic material and the weighed amount (W5) of the additive material to the at least one mixing unit 104. The at least one mixing unit 105 mixes mix the weighed amount (W3) of the hydraulic material and the weighed amount (W5) of the additive material to obtain a further mixture. The at least one mixing unit 104 delivers the further mixture to the at least one packaging unit 105. The at least one packaging unit 105 then stores the further mixture in a further packaging container for use in producing the dry mix construction material. As such, the pozzolanic material is weighed and stored in a packaging container separate from the first packaging container comprising the first mixture and the further packaging container comprising the further mixture of hydraulic material and additive material, as described earlier.

In another implementation, the at least one weighing unit 103 weighs a load of pozzolanic material such that an amount (W4) of the pozzolanic material is in a range of 0 to 23 weight percentage (wt%) of the dry mix construction material, as described earlier. The at least one weighing unit 103 weighs a load of additive material such that an amount (W5) of the additive material is in a range of 1 to 5 weight percentage (wt%) of the dry mix construction material, as described earlier.

Upon weighing, the at least one weighing unit 103 delivers weighed amount (W4) of the pozzolanic material and the weighed amount (W5) of the additive material to the at least one mixing unit 104. The at least one mixing unit 105 then mixes the weighed amount (W4) of the pozzolanic material and the weighed amount (W5) of the additive material to obtain a further mixture. The at least one mixing unit 104 delivers the further mixture to the at least one packaging unit 105. The at least one packaging unit 105 stores the further mixture in a further packaging container for use in producing the dry mix construction material. As such, the hydraulic material is weighed and stored in a packaging container separate from the first packaging container comprising the first mixture and the further packaging container comprising the further mixture of pozzolanic material and additive material, as described earlier.

In one another implementation, the at least one weighing unit 103 weighs a load of hydraulic material such that an amount (W3) of the hydraulic material is in a range of 0 to 19 weight percentage (wt%) of the dry mix construction material, as described earlier. Thereafter, the at least one weighing unit 103 weighs a load of pozzolanic material such that an amount (W4) of the pozzolanic material is in a range of 0 to 23 weight percentage (wt%) of the dry mix construction material, as described earlier. The at least one weighing unit 103 then weighs a load of additive material such that an amount (W5) of the additive material is in a range of 1 to 5 weight percentage (wt%) of the dry mix construction material, as described earlier.

Upon weighing, the at least one weighing unit 103 delivers weighed amount (W3) of the hydraulic material, the weighed amount (W4) of the pozzolanic material, and the weighed amount (W5) of the additive material to the at least one mixing unit 104. The at least one mixing unit 105 mixes the weighed amount (W3) of the hydraulic material, the weighed amount (W4) of the pozzolanic material, and the weighed amount (W5) of the additive material to obtain a further mixture. The at least one mixing unit 104 delivers the further mixture to the at least one packaging unit 105. The at least one packaging unit 105 stores the further mixture in a further packaging container separate from the first packaging container comprising the first mixture.

Further, as described earlier, in one implementation, the system 100 can include only one selection unit 102, weighing unit 103, mixing unit 104, and packaging unit 105. In such implementation, the control unit 106 may determine a sequence of weighing individual materials, a sequence of mixing individual materials, and a sequence of storing either the individual materials or the mixtures. The control unit 106 may then control the operation of the selection unit 102, the weighing unit 103, the mixing unit 104, and the packaging unit 105 in accordance with the determined sequences. In another implementation, the system 100 can include multiple selection units 102, multiple weighing units 103, multiple mixing units 104, and multiple packaging units 105 catering to each of the raw materials. In such implementation, the control unit 106 may control the operations of the multiple selection units 102, the multiple weighing units 103, the multiple mixing units 104, and the multiple packaging units 105 such that these multiple units operate simultaneously.

Further, in all the above implementation, the further packaging containers storing the remaining raw materials either individually or in mixture form are transferred to the silo via the plurality of conveyors from the at least one packaging unit 105 for storage and/ or dispatching to a construction site. This enables easy mixing of appropriate amounts of first mixture comprising of coarse aggregates and fine aggregates, and remaining materials produce the DMC. In one example, the total amount of the weighed raw material(s) is stored/ packed in a single packaging container. In another example, the total amount of the weighed raw material(s) can be segregated and stored/ packed in multiple packaging containers. Further, this enables easy delivering of the first mixture and the remaining materials to a construction site to produce wet construction material. As would be understood, wet construction material is formed by mixing the DMC with water. However, when water is directly mixed with all the raw materials, and specifically with the aggregates, some portion of the water is absorbed by the aggregates themselves due to their inherent surface water absorption characteristic. As a result, the total amount of water required for forming the wet construction material is considerably increased. Further, a variability of strength of the wet construction material is dependent on the amount or thickness of water layer coated on the aggregates. As such, the variability of strength cannot be predicted when all the raw materials are directly mixed with water. This results in a reduction in strength of the wet construction material itself.

To overcome this deficiency and maintaining sufficient water requirement for forming the wet construction material that is workable, cohesive, and assists in placement, typically the aggregates are coated with polymeric treatments prior to mixing with water. Such coating seals irregular surface of the aggregates, thereby preventing the water absorption. However, such coating is difficult to perform at the construction site. In addition, such coating is expensive and labor intensive.

Consequently to overcome the aforementioned deficiencies, in accordance with the present invention, the raw materials are mixed in a predetermined sequence at the construction site to reduce the overall water requirement during formation of the wet construction material. In one implementation, the predetermined sequence is printed on the packaging container(s). In one implementation, the predetermined sequence is printed on a separate instruction sheet and provided along with the packaging container(s). The predetermined sequence indicates the mixing of raw materials as below:

1. forming a slurry comprising of water and the raw materials except the aggregates; wherein the raw materials comprises of hydraulic material, additive material, and optionally pozzolanic material; and

2. combining the slurry thus formed with the first mixture comprising of the coarse aggregates and fine aggregates to coat the first mixture and form the wet construction material.

Thus, when the slurry coats the surface of the aggregates, preferentially the coarse aggregates, the wet slurry plugs up the voids on the surface of the aggregates arising due to its imperfections, which would have otherwise been potential potholes resulting in surface water absorption. It has been found in practice that the absorption of water by aggregates ranges from a mere 0.3% by weight of aggregates to as high as 6-8% by weight of the aggregates. This water does not contribute either in hydration chemistry or in the workability of the wet construction material, but are rather potential dangers which later on create voids due to the formation of capillary pores during drying shrinkage of the concrete, which results in strength reductions and cracks. Due to the viscous nature of the slurry, the voids are just plugged at their surface level and the hardening slurry would not allow any water to impregnate into the voids; though most of the water is bound with cement comprising the paste, even if a trace of free water is available, the coated slurry stops its impregnation into the voids.

Further, the slurry naturally expands in volume due to inherent hydration characteristic of the slurry and further fills the voids/fissures. These fissures, when filled up with this extended hydrated slurry, would act as mechanical shear keys, tending the binder phase as well as the aggregate phase to fix against each other in shear. Hence, when the failure is being developed during loading, these shear keys act as restraints for the failure plane to develop in the interstitial zone, and more force would be required to break these shear keys for the failure plane to propagate through this zone. Hence, the aggregates and binder phases tend to behave like a composite, thereby enhancing the possibilities of greater shear resistance at this interstitial zone, for failure plane to develop. As a result, the compressive strength of the wet construction materials is considerably increased. In addition, the total amount of water is reduced considerably as the amount of water which was absorbed by aggregates is eliminated due to the coating and only amount of water for creating the slurry is required. Such an amount of water required for creating the slurry is predetermined using techniques as known in the art.

In operation, the hydraulic material, the additive material, and optionally the pozzolanic material stored in the further packaging containers, either individually or in mixture form are mixed in a blending unit (not shown in the figure) at the construction site. A predetermined amount of water is added to the blending unit from a water storing unit (not shown in the figure) available at the contrition site, using techniques as known in the art. The predetermined amount of water required for creating the slurry is determined using techniques as known in the art. The hydraulic material, the additive material, and optionally the pozzolanic material and the water are mixed at a first rate of speed in the blending unit to create a slurry. Thereafter, the first mixture comprising of the coarse aggregates and the fine aggregates is added to the blending unit having the slurry therein. The slurry and the first mixture are then mixed at a second rate of speed in the blending unit to obtain the wet construction material. The first rate of speed and the second rate of speed can be determined using techniques as known in the art such that the slurry has enough viscosity to coat the surface of the aggregates to plug the voids. The wet construction material can then be poured at a desired location at the construction site, using mechanisms as known in the art. Thus, the storage/packaging of aggregates (mixture of coarse aggregates and fine aggregates) separate from the storage/packaging of remaining raw materials enables mixing of all the raw materials (or DMC) in accordance with the aforementioned predetermined sequence at the construction site such that overall water requirement during formation of the wet construction material is reduced.

Figures 2 to 9 illustrate example flowcharts that generally illustrate example methods 200 to 900 for producing raw materials used for manufacturing the DMC that is implemented by the system 100, according to the embodiment of the present invention.

As illustrated in Figure 2, at step 201, obtain coarse aggregate having a mode average particle diameter (Dl) in a predetermined range. As described earlier, the coarse aggregate is at least one of processed crushed stone, processed gravel, and processed blue metal.

At step 202, obtain a fine aggregate having a mode average particle diameter (D2) in range of 1/3 to 1/5 of the mode average particle diameter (Dl) of the coarse aggregate. As described earlier, the fine aggregate is processed sand.

At step 203, weigh a load of the coarse aggregate such that an amount (Wl) of the coarse aggregate is in a range of 25 to 50 weight percentage (wt%) of the dry mix construction material.

At step 204, weigh a load of the fine aggregate such that an amount (W2) of the fine aggregate is in a range of 25 to 42 weight percentage (wt%) of the dry mix construction material.

At step 205, mix the weighed amount (Wl) of the coarse aggregate and the weighed amount (W2) of the fine aggregate to obtain a first mixture for use in producing the dry mix construction material.

At step 206, store the first mixture in a first packaging container. In one implementation, as described earlier, each of the remaining materials is now individually weighed and stored in separate packaging containers. Accordingly, referring to Figure 3, at step 301, weigh a load of hydraulic material such that an amount (W3) of the hydraulic material is in a range of 0 to 19 weight percentage (wt%) of the dry mix construction material.

At step 302, store the weighed amount (W3) of the hydraulic material in a further packaging container for use in producing the dry mix construction material.

Referring to Figure 4, at step 401, weigh a load of pozzolanic material such that an amount (W4) of the pozzolanic material is in a range of 0 to 23 weight percentage (wt%) of the dry mix construction material.

At step 402, store the weighed amount (W4) of the pozzolanic material in a further packaging container for use in producing the dry mix construction material.

Referring to Figure 5, at step 501, weigh a load of additive material such that an amount (W5) of the additive material is in a range of 1 to 5 weight percentage (wt%) of the dry mix construction material.

At step 502, store the weighed amount (W5) of the additive material in a further packaging container for use in producing the dry mix construction material.

In one implementation, as described earlier, a set of two or more of the remaining materials are now individually weighed and but are stored together in separate packaging containers. Accordingly, referring to Figure 6, at step 601, weigh a load of hydraulic material such that an amount (W3) of the hydraulic material is in a range of 0 to 19 weight percentage (wt%) of the dry mix construction material.

At step 602, weigh a load of pozzolanic material such that an amount (W4) of the pozzolanic material is in a range of 0 to 23 weight percentage (wt%) of the dry mix construction material.

At step 603, mix the weighed amount (W3) of the hydraulic material and the weighed amount (W4) of the pozzolanic material to obtain a further mixture.

At step 604, store the further mixture in a further packaging container for use in producing the dry mix construction material.

As such, the additive material is weighed and stored in a packaging container separate from the packaging container comprising the first mixture and the further mixture of hydraulic material and pozzolanic material, as described in steps 501 and 502. Referring to Figure 7, at step 701, weigh a load of hydraulic material such that an amount (W3) of the hydraulic material is in a range of 0 to 19 weight percentage (wt%) of the dry mix construction material.

At step 702, weigh a load of additive material such that an amount (W5) of the additive material is in a range of 1 to 5 weight percentage (wt%) of the dry mix construction material.

At step 703, mix the weighed amount (W3) of the hydraulic material and the weighed amount (W5) of the additive material to obtain a further mixture.

At step 704, store the further mixture in a further packaging container for use in producing the dry mix construction material.

As such, the pozzolanic material is weighed and stored in a packaging container separate from the packaging container comprising the first mixture and the further mixture of hydraulic material and additive material, as described in steps 401 and 402.

Referring to Figure 8, at step 801, weigh a load of pozzolanic material such that an amount (W4) of the pozzolanic material is in a range of 0 to 23 weight percentage (wt%) of the dry mix construction material.

At step 802, weigh a load of additive material such that an amount (W5) of the additive material is in a range of 1 to 5 weight percentage (wt%) of the dry mix construction material.

At step 803, mix the weighed amount (W4) of the pozzolanic material and the weighed amount (W5) of the additive material to obtain a further mixture.

At step 804, store the further mixture in a further packaging container for use in producing the dry mix construction material.

As such, the hydraulic material is weighed and stored in a packaging container separate from the packaging container comprising the first mixture and the further mixture of pozzolanic material and additive material, as described in steps 401 and 402.

In one implementation, as described earlier, all the remaining materials are now individually weighed and but are stored together in separate packaging container. Accordingly, referring to Figure 9, at step 901, weigh a load of hydraulic material such that an amount (W3) of the hydraulic material is in a range of 0 to 19 weight percentage (wt%) of the dry mix construction material. At step 902, weigh a load of pozzolanic material such that an amount (W4) of the pozzolanic material is in a range of 0 to 23 weight percentage (wt%) of the dry mix construction material.

At step 903, weigh a load of additive material such that an amount (W5) of the additive material is in a range of 1 to 5 weight percentage (wt%) of the dry mix construction material.

At step 904, mix the weighed amount (W3) of the hydraulic material, the weighed amount (W4) of the pozzolanic material, and the weighed amount (W5) of the additive material to obtain a further mixture.

At step 905, store the further mixture in a further packaging container for use in producing the dry mix construction material.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, and to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the spirit or scope of the present invention.