DESC:TITLE OF THE INVENTION
CEMENT MIX COMPOSITION AND THE METHOD OF MANUFACTURING THEREOF

FIELD OF THE INVENTION
[001] The invention generally relates to the field of cement composition, more particularly to a low water consuming cement composition.

BACKGROUND OF THE INVENTION
[002] Cement is a powdery substance chiefly made up of fly ash, limestone, sand, granulated slag, surfactants and other additives/agents. Broadly, cement can be divided into two types based on the way it sets and hardens i.e. hydraulic cement and non-hydraulic cement. Hydraulic cement is the commonly used cement which hardens on addition of water whereas non-hydraulic cement hardens by carbonation.
[003] Cement can be further sub-divided based upon the method of mixing. One being the manual on-site mix cement and the other being ready-mix cement. Predominantly, manual on-site mix is largely used as compared to the ready-mix cement. The on-site mix cement/concrete is prepared at the construction site by mixing cement, sand or aggregate, and water in an estimated ratio. Pre-dominantly, achieving this ratio consistently is difficult because of lack of skilled labor and due to manual mixing without the use of machinery/technology. Thus, any fluctuation to this ratio compromises the final quality. On the other hand, since the ready-mix cement is prepared using an automated computerized process in controlled conditions, the composition of the ready-mix cement is consistent due to its end-to-end automation. Further, the onsite mix does not require any costly equipment at the construction site.
[004] The strength and durability of mortar and concrete is inversely proportional to the volume of water used ie lower the water / cement ratio higher the strength and durability of hydrated cement mortar and concrete. Since mostly mortar and concrete are produced on-site by mixing cement with sand or aggregate and water, the amount of water added is based on the workability of the mortar and concrete required for application or placing. The amount of water required to achieve a desired workability increases with ambient temperature ie water requirement is high for mortar and concrete production in summer months. Sometimes liquid chemical admixtures are used to achieve water reduction in mortar and concrete during site mixing. Moreover, presence of skilled labor is required for using the liquid chemical. A slight fluctuation in these parameters leads to decline in the strength and durability of the infrastructure.
There is therefore felt a need for a cement mix composition comprising additives or agents or surfactants leading to less water consumption and thereby enhancing the strength and durability of mortar and concrete.

SUMMARY OF THE INVENTION
[005] Disclosed herein is cement mix composition that requires water in low amounts during hydraulic cement, mortar and concrete production. The cement mix composition of the present invention comprises at least one pozzolanic material having particle size in the range of 0.5 to 300 µm and in an amount in the range of 10 to 35%; at least one clinker having particle size in the range of 3000 to 25000 µm and in an amount in the range of 60 to 87%; gypsum having particle size in the range of 5 to 50000 µm and in an amount in the range of 3 to 5% and at least one additive having particle size in the range of 5 to 90 µm and in an amount the range of 0.05 to 1%.
[006] Also disclosed is a method for manufacturing the cement mix composition. The method comprises cross-grinding pre-determined amounts of at least one pozzolanic material, gypsum and clinker to a particle size of 5 to 90 µm followed by blending of pre-determined amount of the additive in a blending unit to obtain the cement mix composition.

BRIEF DESCRIPTION OF THE DRAWINGS
[007] Reference will be made to embodiments of the invention, examples of which may be illustrated in accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1 shows a graph of water reduction of low water consuming cement (LWCC) over PPC and OPC 53 in accordance with an embodiment of the invention; wherein 1 represents LWCC Water Reduction from PPC at Standard Consistency (%); 2 represents LWCC Water Reduction from OPC 53 at Standard Consistency (%) and 3 represents Water for Standard Consistency of Cement Paste (tested as per IS 4031 Part 4) (Gms).
Figure 2 shows a graph of water reduction of concrete with low water consuming cement (LWCC) over PPC and OPC 53 concrete in accordance with an embodiment of the invention; wherein 1 represents LWCC Concrete Water Reduction from PPC at Same Work-ability (%); 2 represents LWCC Concrete Water Reduction from OPC 53 at Same Work-ability (%) and 3 represents Water to Cement Ratio for same workability concrete.
Figure 3 shows a graph of compression strength of concrete with low water consuming cement (LWCC) over PPC and OPC 53 concrete in accordance with an embodiment of the invention; wherein 1 represents Compression Strength – 3 Days (Mpa); 2 represents Compression Strength – 7 Days (Mpa) and 3 represents Compression Strength – 28 Days (Mpa).
Figure 4 shows a graph of durability of concrete with low water consuming cement (LWCC) over PPC and OPC 53 Concrete in accordance with an embodiment of the invention; wherein 1 represents % Lower Chloride Ion Penetration (Coulombs) of LWCC compared to PPC at 28 Days; 2 represents % Lower Chloride Ion Penetration (Coulombs) of LWCC compared to OPC 53 at 28 Days and 3 represents 28 Days Chloride Ion Penetration (Coulomb’s).

DETAILED DESCRIPTION OF THE INVENTION
[008] The present invention is directed towards a cement mix composition and a method for preparing the same. The cement mix composition of the present invention utilizes low amounts of water during hydraulic cement, mortar and concrete production.
[009] In one aspect, the composition comprises predetermined amount of at least one pozzolanic material, at least one clinker, gypsum and at least one additive. The at least one pozzolanic material is present in an amount in the range of 10 to 35%. In an embodiment of the present invention, the at least one pozzolanic material has particle size in the range of 0.5 to 300 µm and is selected from fly ash or calcined clay. The at least one clinker is present in an amount in the range of 60 to 87%. In another embodiment of the present invention the at least one clinker has particle size in the range of 3000 to 25000 µm. Gypsum is present in an amount in the range of 3 to 5%. In yet another embodiment of the present invention gypsum has particle size in the range of 5 to 50000 µm. The at least one additive is present in an amount in the range of 0.05 to 1%. In still another embodiment of the present invention the at least one additive has a particle size in the range of 5 to 90 µm and is selected from retarding agents, plasticizing agents, surfactants or water reducing agents.
[010] The water reducing agent is selected from superplasticizer, plasticizing agent or the retarding agent is selected from lignosulphonates or borate esters. In an embodiment of the present invention, the superplasticizer is selected from Sulfonated melamine formaldehyde condensates or Polycarboxylates ethers. In another embodiment of the present invention, the plasticizing agent is selected from Hydroxylated Carboxylic Acids, Carbohydrates or Lignosulfonates. In yet another embodiment of the present invention, the retarding agent is selected from lignin and lignosulfonates, borax and borate esters, tartaric acid or salt. The superplasticizer and retarding agent are present in a ratio in the range of 1.5 : 1 to 3 : 1.
[011] The composition has an improved workability of concrete with reduced water consumption and efficient retarding properties thereby enhancing the strength and durability of mortar and concrete. The composition also exhibits early curing properties.
[012] In another aspect of the present invention, disclosed is a method for manufacturing the cement mix composition. The method for manufacturing the cement mix composition comprises the steps of cross-grinding pre-determined amounts of at least one pozzolanic material, gypsum and clinker to a particle size of 5 to 90 µm followed by blending of pre-determined amount of the additive in a blending unit to obtain the cement mix composition.
[013] Alternatively, gypsum and clinker are ground to the particle size of 5 to 90 µm followed by sieving/classifying fly ash through a sieve having a pore size of 90 µm to obtain sieved fly ash having particle size below 90 µm. Further, the sieved fly ash and the additive are cross-blended with the grinded gypsum and clinker in a blending station to obtain the cement mix composition.

[014] EXAMPLES
Example 1:
The Low Water Consuming Cement mix composition (LWCC) of the present invention was tested for the water consumption properties with Portland Pozzolana Cement (PPC) and Ordinary Portland Cement (OPC 53). The experimental details are illustrated in the Tables 1, 2 and 3 herein below as well as in Figure 1, Figure 2, Figure 3 and Figure 4.
Normal PPC Normal OPC 53 LWCC - 0.35% LWCC - 0.30% LWCC - 0.25% LWCC - 0.20% LWCC - 0.15%
Cement (in grams) 300 300 300 300 300 300 300
Water for Standard Consistency of Cement Paste (tested as per IS 4031 Part 4) (Gms) 92 90 65.2 65.3 66 66.7 68.2
Standard Consistency % 30.7% 30.0% 21.7% 21.8% 22.0% 22.2% 22.7%
LWCC Water Reduction from PPC at Standard Consistency (%) 29.1% 29.0% 28.3% 27.5% 25.9%
LWCC Water Reduction from OPC 53 at Standard Consistency (%) 27.6% 27.4% 26.7% 25.9% 24.2%
Table 1

Cement composition of the present invention i.e. Low Water Consuming Cement (LWCC) over PPC and OPC 53 Concrete
Normal PPC Normal OPC 53 LWCC – Concrete
Concrete Proportion – Cement : Fine Aggregate : Coarse Aggregate 1 : 2 : 3 1 : 2 : 3 1 : 2 : 3
Water to Cement Ratio for same workability 0.65 0.65 0.48
LWCC Concrete Water Reduction from PPC at Same Work-ability (%) 26.2%
LWCC Concrete Water Reduction from OPC 53 at Same Work-ability (%) 26.2%
Table 2

Cement composition of the present invention i.e. Low Water Consuming Cement (LWCC) over PPC and OPC 53 Concrete
Normal PPC Normal OPC 53 LWCC – Concrete
Concrete Proportion – Cement : Fine Aggregate : Coarse Aggregate 1 : 2 : 3 1 : 2 : 3 1 : 2 : 3
Water to Cement Ratio for Same Workability 0.65 0.65 0.48
Compression Strength (as per IS 516)
Compression Strength – 3 Days (Mpa) 6.2 13.9 14.7
% Higher Compression Strength of LWCC compared to PPC at 3 Days 137.1%
% Higher Compression Strength of LWCC compared to OPC 53 at 3 Days 5.8%
Compression Strength – 7 Days (Mpa) 9.7 19.3 24.2
% Higher Compression Strength of LWCC compared to PPC at 7 Days 149.5%
% Higher Compression Strength of LWCC compared to OPC 53 at 7 Days 25.4%
Compression Strength – 28 Days (Mpa) 24.3 34.6 44.4
% Higher Compression Strength of LWCC compared to PPC at 28 Days 82.7%
% Higher Compression Strength of LWCC compared to OPC 53 at 28 Days 28.3%
Durability (as per ASTM C 1202, lower coulomb’s results in higher durability)
28 Days Chloride Ion Penetration (Coulomb’s) 5419 6217 2797
% Lower Chloride Ion Penetration (Coulombs) of LWCC compared to PPC at 28 Days 48.3%
% Lower Chloride Ion Penetration (Coulombs) of LWCC compared compared to OPC 53 at 28 Days 55%
Table 3

Table 1 depicts that the cement mix composition of the present invention consumes 25.9 to 29.1% less water than PPC and 24.2% to 27.6% less water than OPC 53 to make cement paste of same standard consistency.
Table 2 illustrates that the cement mix composition of the present invention consumes 26.2% less water than PPC or OPC 53 to make concrete of same initial workability.

Table 3 illustrates that the concrete compression strength of the cement mix composition of the present invention is 137.1%, 149.5% and 82.7% higher than PPC concrete and 5.8%, 25.4% and 28.3% higher than OPC 53 concrete at 3, 7 and 28 days respectively. The cement mix composition of the present invention exhibits higher resistance to chloride ion penetration by 48.3% and 55% as compared to PPC and OPC 53 concrete respectively.

[015] While the present invention has been described with respect to certain embodiments, it will be apparent to those skilled in the art that various changes and modification may be made without departing from the scope of the invention as defined in the following claims.

,CLAIMS:WE CLAIM:

1.) A cement mix composition, said composition comprising
- at least one pozzolanic material having particle size in the range of 0.5 to 300 µm and in an amount in the range of 10 to 35%;
- at least one clinker having particle size in the range of 3000 to 25000 µm and in an amount in the range of 60 to 87%;
- gypsum having particle size in the range of 5 to 50000 µm and in an amount in the range of 3 to 5%; and
- at least one additive having particle size in the range of 5 to 90 µm and in an amount the range of 0.05 to 1%.

2.) The composition as claimed in claim 1, wherein said at least one pozzolanic material is selected from fly ash or calcined clay.

3.) The composition as claimed in claim 1, wherein said at least one additive is selected from retarding agents, plasticizing agents, surfactants or water reducing agents.

4.) The composition as claimed in claim 1, wherein said retarding agent is selected from lignosulphonates or borate esters.

5.) The composition as claimed in claim 3, wherein said water reducing agent is selected from superplasticizer or plasticizing agent.

6.) The composition as claimed in claim 5, wherein said superplasticizer and plasticizing agent are selected from polycarboxylate ether-based (PCE) or sulfonated naphthalene formaldehyde condensates (SNF).

7.) The composition as claimed in claim 3 and 5, wherein said superplasticizer or retarding agent are present in a ratio in the range of 1.5: 1 to 3: 1.

8.) A method for manufacturing a cement mix composition as claimed in claim 1 comprising the steps of:
- cross-grinding pre-determined amounts of at least one pozzolanic material, gypsum and clinker to a particle size of 5 to 90 µm followed by blending of pre-determined amount of the additive in a blending unit to obtain the cement mix composition.

9.) A method for manufacturing a cement mix composition as claimed in claim 1 comprising the steps of:
- grinding gypsum and clinker to the particle size of 5 to 90 µm followed by sieving/classifying fly ash through a sieve having a pore size of 90 µm to obtain sieved fly ash having particle size below 90 µm; and
- cross-blending the sieved fly ash and the additive with the ground gypsum and clinker in a blending station to obtain the cement mix composition.