DESC:FIELD OF INVENTION
The present invention provides for superplasticizer formulation for increasing durability of concrete structures, based on synergistically co-operative ingredients viz. select special amines, crystalline compounds and glycols in combination with PCE (polycarboxylate ether) mixtures adapted as a superplasticizer and reducing concrete permeability and enhancing overall durability at the same time.

BACKGROUND ART
Currently the market offers three different admixtures to achieve the intended properties such as core function as a superplasticizer, reduction in water permeability, shrinkage and resistance to corrosion of rebar. These are separate products offering the desired performance individually and available in the market as super plasticizer, shrinkage reducing admixture, corrosion inhibiting admixture and admixture for reducing concrete permeability. This necessarily involve usage of multiple admixture at site depending on the type of final concrete required and would also impact overall costing considering inventory management and hassle of using multiple products.
On such prevalently known superplasticizers, reference is invited to US2008/0087199A1 disclosing a composition comprising a hydraulic binder, a low molecular weight glycol having the formula CnH2n(OH)2 wherein n is an integer from 2 to 10, preferably 2 to 9, and a fluorinated surfactant capable of reducing the surface tension of pure water to a value below 30 mN/m at a concentration of 1% or less. Also relates to a wet mortar or concrete composition comprising a hydraulic binder, a low molecular weight glycol having the formula CnH2n(OH)2 wherein n is an integer from 2 to 10, preferably 2 to 9, and a fluorinated surfactant capable of reducing the surface tension of pure water to a value below 30 mN/m at a dosage of 1% or less, water and sand and/or aggregates and/or fillers.
US5622558 is directed to cement admixture composition composed of a mixture of alkylene glycol and fume silica to provide a means of inhibiting drying shrinkage and enhancing compressive strength.
EP 1911731B1 teaches a composition comprising a hydraulic binder, hexylene glycol and a fluorinated surfactant selected from a fluoroaliphatic polyester capable of reducing the surface tension of pure water to a value below 30 mN/m at a concentration of 1% or less.
Reference is also invited to corrosion inhibitors for steel in concrete: State-of-the-art report Construction and Building Materials 22 (2008) 609–622 discloses corrosion inhibitors used in concrete and is based on published studies in the last decade. Emphasis was given to the most commonly used inhibitors such as aminoalcohols (AMAs), calcium nitrites (CN) and sodium monofluorophosphates (MFPs). This literature report presents information related to (a) basic mechanism study, which teaches mechanism of protection provided by inhibitors, (b) effectiveness of inhibitors against corrosion in chloride contaminated and carbonated concrete, which deals with the preventive and curing effect of the inhibitors in different environments, (c) penetrability of the inhibitor, which underlines some difficulties of penetration into concrete for migrating corrosion inhibitors (MCIs), (d) influence on fresh and hardened concrete properties, which compares fresh concrete properties, mechanical performance and durability with and without inhibitor, (e) field trials, which gives the limited data on the long-term performance of the inhibitors in real structures.
While various such admixtures are known it is a longfelt need in the art to provide for a single superplasticizer formulation that would be capable of providing the functionalities of not only a superplasticizer, but also drying shrinkage reducer, water permeability reducer and corrosion inhibitor, all in a single product formulation thus free from the requirement of usage of different solutions/formulations, that would otherwise efficiently tackle and enhance at least four different aspects of concrete.

OBJECTS OF THE INVENTION
It is thus the primary object of the present invention to provide for superplasticizer formulation based on synergistically co-operative ingredients comprising additives viz. select special amines, crystalline compounds & glycols in combination with PCE (polycarboxylate ether) mixtures that would be adapted as a superplasticizer and would reduce concrete permeability and enhance overall durability at the same time.
It is another object of the present invention to provide for said synergistic superplasticizer formulation that would not involve usage of multiple admixture at site depending on the type of final concrete required and would be free of any impact on overall costing considering inventory management and hassle of using multiple products.
It is another object of the present invention to provide for said synergistic superplasticizer formulation that would provide for the combined functionality of superplasticizer, drying shrinkage reducer, water permeability reducer and corrosion inhibitor.
It is yet another object of the present invention to provide for a single pack formulation which would not only serve as a solution for all the above functionalities but would also be storage stable.
It is still another object of the present invention to provide for a single product solution which enhances least four different said aspects of concrete together with enabling at least 15% reduction in drying shrinkage and at least 10% reduction in water permeability.

SUMMARY OF THE INVENTION

Thus according to the basic aspect of the present invention there is provided a single pack superplasticizer formulation comprising a synergistic combination of Diethylene glycol, Potassium sodium tartarate, Polyether diamine incorporated in amino alcohol free blend of polycarboxylate ether mix, Sodium ligno sulfonate, Sodium gluconate, suitable for correcting multiple concrete defects thereby enhancing durability of concrete.

Preferably in said single pack superplasticizer formulation said Diethylene glycol, Polyether diamine of average mol. wt. of about 230 and Potassium sodium tartarate is incorporated in the ratio of Diethylene glycol: Polyether diamine: Potassium sodium tartarate:: 0.5-3.0: 0.5-3.0: 0.05-0.3 in said formulation that is stable for at least 12 months/years without any loss of stability corresponding to efficiency.

More preferably said single pack superplasticizer formulation is provided wherein said polycarboxylate ether (PCE) mix comprises water reducer polycarboxylate ether, slump retainer polycarboxylate ether, and defoamer polycarboxylate ether that differs based on the mol.wt.,
Wherein water reducer PCE is obtained of polymerization of methycrylic acid and vinyl polyethylene glycol VPEG-2400, said water reducer PCE having weight average molecular weight (Mw) ˜20,000;
Wherein said slump retainer PCE is obtained of polymerization of methycrylic acid, 2-hydroxy propyl acrylate and vinyl polyethylene glycol VPEG-2400, said slump retainer PCE having weight Average Molecular Weight (Mw)˜25,000;

Wherein said defoamer PCE is a fatty acid ester such as stearic acid ester based non-ionic surfactant in combination with glycol.

Preferably said single pack superplasticizer formulation is provided wherein said formulation comprises (a) water reducer Polycarboxylate ether in the levels of 10 to 60 wt.%;
(b) slump retainer Polycarboxylate ether in the levels of 8 to 40 wt.%;
(c) defoamer Polycarboxylate Ether in the levels of 0.01-0.2 wt.%;
(d) Sodium lingo sulfonate: 0.5-4 wt.%;
(e) Sodium gluconate: 3-10 wt.%;
(f) Diethylene glycol: 0.5-3.0 wt.%;
(g) Potassium sodium tartarate: 0.05-0.3 wt.%;
(h) Polyether amine (preferably Jeffamine D 230) of that is a difunctional, primary amine with an average molecular weight of about 230: 0.5-3.0 wt.%.

According to another preferred aspect of the present invention there is provided said single pack superplasticizer formulation advantageously poised as a single pack synergistic superplasticizer formulation free of involvement of multiple mixtures at the site of application depending on different type of concrete requiring overall costing including inventory management and hassle of involving multiple products and is adapted for combined functionality of superplasticizer, drying shrinkage reducer, water impermeability and corrosion inhibitor of casted concrete favouring upto 42.11% reduction in drying shrinkage, 21% reduction in chloride ion penetration and upto 49.6% reduction in water permeability.

According to yet another preferred aspect of the present invention there is provided a process to provide a single pack superplasticizer formulation comprising the steps of simple blending said ingredients in a high speed mixer with variable speed drive at rpm ranging from around 20-40.

The weight percentage of the materials used in making concrete vary as different geographies have different nature and chemical composition of coarse and fine aggregates along with this there are various brands of cements, hence to achieve the required water reduction in the concrete along with the concrete to remain workable (slump retention) as per the site requirements, the weight percentage of the various raw materials used in making the present admixture formulation varies within the wt.% ranges as scoped.
Thus when the proportions of the materials in the concrete mix design vary, then accordingly the amount of usage of WR, SR PCE varies within the select wt.% ranges as per the required rheology of the concrete by maintaining the wt.% levels of Diethylene glycol: Potassium sodium tartarate: Jeffamine D-230= 0.5-3.0: 0.05-0.3: 0.5-3.0 in the aforesaid range.

BRIEF DESCRIPTION OF FIGURES

Figure 1: illustrates the SEM image for control concrete mix M25;
Figure 2: illustrates the SEM image for comparative formulations under Table 4;
Figure 3: illustrates the SEM image for the successful trials in accordance with the invention;
Figure 4: illustrates the SEM image for conventionally known superplasticizer formulation.

DETAILED DESCRIPTION OF THE INVENTION

As discussed hereinbefore, the present invention provides for a superplasticizer formulation comprising a synergistic mix of ingredients that synergistically co-operates to not only serve as a superplasticizer in different concrete mix designs but also enables reduction in water permeability, reduction in drying shrinkage and reduction in chloride ion penetration in casted concrete.

According to an aspect of the present invention a superplasticizer formulation is provided comprising aqueous polymer of polycarboxylate ether mixtures for a collapsed and workable mix along with additives like defoamer, small amount of other plasticizers such as ligno-sulfonates, sodium gluconate, in combination with select special liquid additive involving special select amines, which said formulation also involving a blend of solid double salt enables the final superplasticizer formulation that not only provides reduction in drying shrinkage, but also provides corrosion protection of steel reinforcement bars without altering the setting time of concrete. The special amines get chemisorbed on the metal surface of rebars and displace the adsorbed water and electrolyte from the surface.

EXAMPLES:

The present invention provides for a single pack superplasticizer formulation comprising a synergistic combination of Diethylene glycol, Potassium sodium tartarate, Polyether amine together with a blend of polycarboxylate ether mix, Sodium ligno sulfonate, Sodium gluconate.

While no such combination of ingredients were employed in the state of the art to improve the workability of the concrete, specifically diethylene glycol, potassium sodium tartarate and polyether amine were least known to influence the workability and the strength of the concrete, being the two most basic factors of concrete, in combination with PCEs (superplasticizers) as a single pack stable formulation.
Currently specific admixtures are commercially made available for specific functions i.e. for drying shrinkage reduction or for water impermeability. This unavailability of a single pack stable formulation as a product per se suiting multiple purpose effects for treating multiple concrete defects is the need of the day that could be addressed by the unique formulation of the present invention. Further while glycols were employed in reducing the drying shrinkage in the concrete as reported in a plethora of patents and research papers, the same could never be implemented in a single superplasticizer formulation to impact multiple functionalities. Along with glycol, Potassium sodium tartrate together surprisingly reduced the permeability in concrete via crystal growth formation with the by-products of cement hydration.
Added to the above while amino alcohols are used as corrosion inhibitor such as diethanol amine, triethanol amine, etc. but they severely hamper the setting time of concrete as they are mostly employed as cement or concrete accelerators, but in the present invention the same could be avoided, and instead when polyether diamines was employed with other ingredients of the formulation could significantly reduce the ingress of chloride ion penetration and such extremely convincing results are elucidated under the below Tables. Further to the above, polyether diamines employed does not impact the setting time of the concrete when used at the select levels of 0.5% to 3% in the synergistic formulation. Further it also synergistically helps in decreasing the chloride ion penetration in the concrete by getting adsorbed on the surface of the iron rebar and forms a resistive barrier against the chloride by formation of a protective film. Moreover, the single pack superplasticizer formulation of the present invention involving a synergistic combination of select ingredients that surprisingly provides multipurpose effects for treating multiple concrete defects which is the peculiarity and uniqueness of the formulation, and which effects cannot be said to flow from the inherent characteristics of the ingredients employed.
The synergistic effects are seen more prominently when the ratio of the ingredients are in the ratio as per the following: Diethylene glycol: Potassium sodium tartarate: Jeffamine D-230= 0.5-3.0: 0.05-0.3: 0.5-3.0. This can be attributed for longer period of presence of the Potassium sodium tartarate ions in the capillary pores in water medium. The glycol which reduces the surface tension of the liquid to evaporate enables the crystalline additive to be present for a longer duration in the capillary pores enabling it to react with the by- products of cement hydration forming insoluble crystals, making the concrete less permeable.
EXAMPLES
Exemplary formulation details in Tables 1-3 below in accordance with the invention:
The materials employed are water reducing type Polycarboxylate ether from Himadri Speciality Chemical Ltd.: 10-60 wt.%; Slump retaining type Polycarboxylate ether from Himadri Specialty Chemical Ltd.: 8-30%; Polycarboxylate ether Defoamer type is a fatty acid ester such as stearic acid ester based non-ionic surfactant in combination with glycol.
Table 1
MaximoPlast PX 100
Raw Material wt%
Water 72.55
Biopack 1 0.1
Biopack 2 0.1
Sodium Gluconate 3
Sodium Lignosulfonate 3
PC Defoamer 0.1
WR PCE 12
SR PCE 8
Diethylene glycol 0.5
Jeffamine D 230 0.5
Potassium Sodium Tartarate 0.15
Total 100

Table 2
MaximoPlast PX 200
Raw Material wt%
Water 50.55
Biopack 1 0.1
Biopack 2 0.1
Sodium Gluconate 4
Sodium Lignosulfonate 1
PC Defoamer 0.1
WR PCE 25
SR PCE 18
Diethylene glycol 0.5
Jeffamine D 230 0.5
Potassium Sodium Tartarate 0.15
Total 100

Table 3

MaximoPlast PX 300
Raw Material wt%
Water 28.05
Biopack 1 0.1
Biopack 2 0.1
Sodium Gluconate 5
Sodium Lignosulfonate 0.5
PC Defoamer 0.1
WR PCE 35
SR PCE 30
Diethylene glycol 0.5
Jeffamine D 230 0.5
Potassium Sodium Tartarate 0.15
Total 100

Stability of the above formulation under Tables 1-3 conforms to IS 9103 and has a stability of 12 months. The solution is stable at all the mentioned weight percentages of the individual Raw Material as per the principal scope of the present invention.
Table 4 including comparative formulations
Trial No. Trial Details PCE (Polycarboxylate ether) Diethylene Glycol Jeffamine D 230 (polyetheramine) Potassium Sodium Tartarate RCPT (charge passed-Coloumbs) Drying Shrinkage Water Permeability (cm)
1 Control (CONCRETE ALONE, M25 grade) NA NA NA NA 8566 0.1 139.7
2 Control+ DEG NA 1 NA NA 7945 0.03 120.7
3 Control + D230 NA NA 1 NA 7142 0.07 124.9
4 Control + KNaTar NA NA NA 1 4596 0.06 98
Trial No. Trial Details on said M25 grade concrete PCE (Polycarboxylate ether) Diethylene Glycol Jeffamine D 230 (polyetheramine) Potassium Sodium Tartarate RCPT (charge passed-Coloumbs) Drying Shrinkage Water Permeability (cm)
5 PCE 0.50% NA NA NA 5949 0.08 118.7
6 PCE+DEG 0.50% 1 NA NA 6028 0.045 116.3
7 PCE+D-230 0.50% NA 1 NA 3760 0.06 106.3
8 PCE+KNaTar 0.50% NA NA 0.5 5463 0.07 104.5
Trial No. Trial Details on said M25 grade concrete PCE (Polycarboxylate ether) Diethylene Glycol Jeffamine D 230 (polyetheramine) Potassium Sodium Tartarate RCPT (charge passed-Coloumbs) Drying Shrinkage Water Permeability (cm)
9 Control+ DEG+D-230 NA 1 1 NA 5042 0.075 108.5
10 Control + DEG+KNaTar NA 1 NA 1 5148 0.07 104.7
11 Control+D-230+KNaTar NA NA 1 1 5217 0.065 115.7
12 Control+DEG+D-230+KNaTar NA 1 1 0.5 4394 0.048 100.5
Trial No. Trial Details on said M25 grade concrete PCE (Polycarboxylate ether) Diethylene Glycol Jeffamine D 230 (polyetheramine) Potassium Sodium Tartarate RCPT (charge passed-Coloumbs) Drying Shrinkage Water Permeability (cm)
13 PCE + DEG+KNaTar+D-230 0.50% 1 0.2 0.1 5147 0.05 89.5
14 PCE + DEG+KNaTar+D-230 0.50% 1 2 1 4717 0.04 100.8
15 PCE + DEG+KNaTar+D-230 0.50% 1 0.2 1 4750 0.045 106.4
16 PCE + DEG+KNaTar+D-230 0.50% 1 2 0.1 3126 0.035 82.6
Trial No. Trial Details on said M25 grade concrete PCE (Polycarboxylate ether) Diethylene Glycol Jeffamine D 230 (polyetheramine) Potassium Sodium Tartarate RCPT (charge passed-Coloumbs) Drying Shrinkage Water Permeability (cm)
17 PCE + DEG+KNaTar+D-230 0.50% 0.2 1 0.1 4596 0.045 102.3
18 PCE + DEG+KNaTar+D-230 0.50% 2 1 1 7142 0.04 116.3
19 PCE + DEG+KNaTar+D-230 0.50% 0.2 1 1 8566 0.06 118.7
20 PCE + DEG+KNaTar+D-230 0.50% 2 1 0.1 3745 0.03 92.4
Trial No. Trial Details on said M25 grade concrete PCE (Polycarboxylate ether) Diethylene Glycol Jeffamine D 230 (polyetheramine) Potassium Sodium Tartarate RCPT (charge passed-Coloumbs) Drying Shrinkage Water Permeability (cm)
21 PCE + DEG+KNaTar+D-230 0.50% 0.2 0.2 0.5 5610 0.055 106.3
22 PCE + DEG+KNaTar+D-230 0.50% 2 2 0.5 4528 0.045 109
23 PCE + DEG+KNaTar+D-230 0.50% 0.2 2 0.5 4865 0.06 112.7
24 PCE + DEG+KNaTar+D-230 0.50% 2 0.2 0.5 5247 0.04 109.5
Trial No. Trial Details on said M25 grade concrete PCE (Polycarboxylate ether) Diethylene Glycol Jeffamine D 230 (polyetheramine) Potassium Sodium Tartarate RCPT (charge passed-Coloumbs) Drying Shrinkage Water Permeability (cm)
25 PCE + DEG+KNaTar+D-230 0.50% 1 1 0.5 4120 0.65 100.7
26 PCE + DEG+KNaTar+D-230 0.50% 10 10 5 4756 0.02 96.3
27 PCE + DEG+KNaTar+D-230 0.50% 0.2 0.2 0.1 5312 0.08 88.5
28 PCE + DEG+KNaTar+D-230 0.50% 5 5 2 4457 0.035 88

The above tests were carried out in M-25 grade concrete mix as control with high porosity to have better differences in studying and analyzing the data which had the following contents per meter cube of the concrete: 1. Cement (Ultratech OPC 53): 320 Kg; 2. 20 mm Aggregates: 700 Kg; 3. 10 mm Aggregates: 410 Kg; 4.Crushed Sand: 830 Kg; 5. Water: 170 Kg; the SEM image under Figure 1 showed no crystal growth.
Aggregates incorporated in the mix are conventionally known components of concrete which are mostly obtained from mining and they serve as reinforcement material to add strength to concrete.
From the above trials under Table 4 including the comparative formulations as demonstrated through the SEM images under Figure 2 it could be seen that no proper crystal growth could be observed with regard to crystal density, whereas, for successful Trial nos. 16 and 20 the desired crystal growths and crystal density could be observed and the same possibly enabled desired RCPT (Rapid Chloride penetration Test) charge within 4000 as desired and further explained below together with the desired low dry shrinkage and water permeability when taken together with polycarboxylate ether at smaller and constant levels, which other comparative formulation could not attain, establishing that indeed the wt.% levels of the actives of Diethylene glycol: Jeffamine D-230: Potassium sodium tartarate = 0.5-3.0: 0.5-3.0: 0.05-0.3 should be maintained in the aforesaid ratios. The aforesaid successful trials are also demonstrated through SEM image under Figure 3 where good crystal growth together with good crystal density could be observed. The above select ratios of said selective ingredients worked well together with M-25 grade concrete mix and even other concrete mixes as demonstrated below and even when PCE is even employed in higher levels as scoped by the single pack superplasticizer formulation of the present invention to provide for the desired effects revealing synergistic effects based on the select actives of Diethylene glycol: Jeffamine D-230: Potassium sodium tartarate provided in select wt% ranges when involved in the present formulation together with various levels of PCE and when taken together with Sodium ligno sulfonate, Sodium gluconate that is tested on concrete mix.
When conventionally known superplasticizer BASF polyhead 6153 in concrete mix was tried, the SEM image under Figure 4 for the same reflected no crystal growth, however, presence of network of faint string like features could be observed across the sample.
Table 5 onwards refers to trials on 3 different formulations i.e. MaximoPlast PX 100, MaximoPlast PX 200 and MaximoPlast PX 300 in 3 different concrete mixes i.e. M-35, M-45 and M-60 respectively that displayed versatility in enabling the desired attributes wherein the differential actives (1)-(3) below were involved in the following fixed weight percentages in all the 3 different formulations comprising the rest of the ingredients as per Tables 1-3 above:
1. Diethylene glycol: 0.5%; 2. Jeffamine D-230: 0.5%; 3. Potassium Sodium Tartarate: 0.15% (Average Mol wt. 230)
The above weight percentages were fixed in order to match the target Raw material cost of the product.

Table 5: Drying Shrinkage

Sample Test Method used Age of test Gauge length
(mm) Initial Wet length
(mm) Final drying length (mm) Drying Shrinkage (%) (%) Drying shrinkage reduction over control
Control
(IS 1857 M-45 concrete mix) IS:1199-1959 (Reaffired 2013 28 days 300.40 16.110 16.024 0.029 0.00
IS 1858 M-45 Maximoplast PX200 (in accordance with the present invention) IS:1199-1959 (Reaffired 2013 28 days 300.10 16.023 15.962 0.020 31.03
Control IS 1866 M-45 IS:1199-1959 (Reaffired 2013 28 days 300.40 18.949 18.873 0.025 0.00
IS 1868 M-45 Maximoplast PX200 (in accordance with the present invention) IS:1199-1959 (Reaffired 2013 28 days 300.00 19.119 19.072 0.016 36.00
M-45 concrete mix: Cement (Ultratech OPC 53): 400 Kg; Fly Ash: 100 Kg; 20 mm Aggregates: 613 Kg; 10 mm Aggregates: 407 Kg; Crushed Sand: 664 Kg; Water: 192 Kg
IS numbers below are the sample numbers as tested in the laboratory, taken from different portions of the mix and the results obtained may be considered to average out.
Table 6: Drying Shrinkage
Sample Test Method used Age of test Gauge length
(mm) Initial Wet length
(mm) Final drying length (mm) Drying Shrinkage (%) (%) Drying shrinkage reduction over control
Control
(IS 1860 M-60) IS:1199-1959 (Reaffired 2013 28 days 300.40 23.448 23.384 0.021 0.00
IS 1862 M-60 Maximoplast PX300 (in accordance with the present invention) IS:1199-1959 (Reaffired 2013 28 days 300.20 19.671 19.625 0.015 28.57
Control IS 1865 M-60 IS:1199-1959 (Reaffired 2013 28 days 300.20 18.357 18.243 0.038 0.00
IS 1867 M-60 Maximoplast PX300 (in accordance with the present invention) IS:1199-1959 (Reaffired 2013 28 days 300.10 20.153 20.086 0.022 42.11
M-60 concrete mix: Cement (Ultratech OPC 53): 450 Kg; Fly Ash: 150 Kg; 20 mm Aggregates: 635 Kg; 10 mm Aggregates: 370 Kg; Crushed Sand: 618 Kg Water: 180 Kg.
Table 7: Drying Shrinkage
Sample Test Method used Age of test Gauge length
(mm) Initial Wet length
(mm) Final drying length (mm) Drying Shrinkage (%) (%) Drying shrinkage reduction over control
M-35 Control (IS 1859) IS:1199-1959 (Reaffired 2013 28 days 300.4 23.448 23.358 0.030 0.00
M-35 Maximoplast PX 100 (IS 1861) (in accordance with the present invention) IS:1199-1959 (Reaffired 2013 28 days 300.2 19.671 19.615 0.019 37.74
M-35 Control (IS 1863) IS:1199-1959 (Reaffired 2013 28 days 300.2 18.546 18.442 0.035 0.00
M-35 Maximoplast PX 100 (IS 1864) (in accordance with the present invention) IS:1199-1959 (Reaffired 2013 28 days 300.1 20.352 20.287 0.022 37.14
M-35 concrete mix: Cement (Ultratech OPC 53): 340 Kg; Fly Ash: 85 Kg; 20 mm Aggregates: 662 Kg; 10 mm Aggregates: 421 Kg; Crushed Sand: 733 Kg; Water: 170 Kg
From the above Tables 6 and 7 it was found that much more than 15% drying shrinkage reduction could be attained.
Table 8: Water Permeability Test Report (Application of water pressure 500 kPa ±50 for 72 hrs.
Sample Test Method Used Weight of specimen (kgs) After 3 days weight of specimen (kgs) Penetration(mm) Percentage reduction in penetration
M-35 Control (IS 1859) BS EN
12390-8:2009 8.117 8.218 45.00 NA
M-35 Maximoplast PX 100 (IS 1861) (in accordance with the present invention) BS EN
12390-8:2009 8.013 8.125 40.00 11.11%
M-35 Control (IS 1863) BS EN
12390-8:2009 8.137 8.190 30.00 NA
M-35 Maximoplast PX 100 (IS 1864) (in accordance with the present invention) BS EN
12390-8:2009 8.279 8.311 22.00 26.60%

M-35 concrete mix: Cement (Ultratech OPC 53): 340 Kg; Fly Ash: 85 Kg; 20 mm Aggregates: 662 Kg; 10 mm Aggregates: 421 Kg; Crushed Sand: 733 Kg; Water: 170 Kg

Table 9: Water Permeability Test Report (Application of water pressure 500kPa±50 for 72 hrs.
Sample Test Method used Weight of specimen (kgs) After 3 days Weight of specimen (kgs) Penetration (mm) Percentage reduction in penetration
M-45 Control (IS 1857) BS EN
12390-8:2009 7.928 8.021 30.00 NA
M-45 Maximoplast PX 200 (IS 1858) (in accordance with the present invention) BS EN
12390-8:2009 8.053 8.131 25.00 16.60%
M-45 Control (IS 1866) BS EN
12390-8:2009 8.185 8.243 30.00 NA
M-45 Maximoplast PX 200 (IS 1868) (in accordance with the present invention) BS EN
12390-8:2009 8.322 8.346 15.10 49.60%

Table 10: Water Permeability Test Report (Application of water pressure 500kPa±50 for 72 hrs.
Sample Test Method used Weight of specimen (kgs) After 3 days Weight of specimen (kgs) Penetration (mm) Percentage reduction in penetration
M-60 Control (IS 1860) BS EN
12390-8:2009 7.897 7.958 25.00 NA
M-60 Maximoplast PX 300 (IS 1862) (in accordance with the present invention) BS EN
12390-8:2009 8.103 8.165 20.00 20%
M-60 Control (IS 1865) BS EN
12390-8:2009 7.984 8.031 24.00 NA
M-60 Maximoplast PX 300 (IS 1867) (in accordance with the present invention) BS EN
12390-8:2009 8.212 8.236 10.10 41.60%

From the above Tables 8-10 it was found that at least and much more than 10% reduction in water permeability could be attained as per the targeted objectives.

Table 11: Rapid Chloride penetration Test
Sample Test Method used Age of Testing Reading (Coulombs) Average
IS 1863 M-35 Control ASTM-C1202-2019 28 days 5847 5672
28 days 5566
28days 5603

IS 1864 M-35 Maximoplast PX100 (in accordance with the present invention) ASTM-C1202-2019 28 days 4523 4458
28 days 4450
28days 4400
Guidance of Interpretation of Results (as per ASTM 1202-2019)
Charge Passed (Coloumbs) Chloride ion penetrability
>4000 High
2000-4000 Moderate
1000-2000 Low
Low 100-1000 Very low
<100 Negligible

Table 12: Rapid Chloride penetration Test
Sample Test Method used Age of Testing Reading (Coulombs) Average
IS 1866 M-45 Control ASTM-C1202-2019 28 days 5109 5052
28 days 4982
28days 5065

IS 1868 M-45 Maximoplast PX200 (in accordance with the present invention) ASTM-C1202-2019 28 days 2478 2467
28 days 2521
28days 2402
Guidance of Interpretation of Results (as per ASTM 1202-2019)
Charge Passed (Coloumbs) Chloride ion penetrability
>4000 High
2000-4000 Moderate
1000-2000 Low
Low 100-1000 Very low
<100 Negligible

Table 13: Rapid Chloride penetration Test
Sample Test Method used Age of Testing Reading (Coulombs) Average
IS 1865 M-60 Control ASTM-C1202-2019 28 days 4472 4506
28 days 4490
28days 4556

IS 1867 M-60 Maximoplast PX300 (in accordance with the present invention) ASTM-C1202-2019 28 days 1230 1259
28 days 1348
28days 1198
Guidance of Interpretation of Results (as per ASTM 1202-2019)
Charge Passed (Coloumbs) Chloride ion penetrability
>4000 High
2000-4000 Moderate
1000-2000 Low
Low 100-1000 Very low
<100 Negligible

The said ingredients of the formulations preferably in select % ranges employed were found to be compatible and stable as a single pack multipurpose formulation, stable for at least 12 months/ years without any loss of stability corresponding to its original related efficiency. Any change in the components of the formulation including the preferred percentages in which it is present compromised its stability and efficiency.
Moreover, when the proportions of the materials in the concrete mix varies then accordingly the amount of WR, SR PCE would vary as per the required rheology of the concrete still falling in the broad wt% ranges. Also naturally the amount of concrete increase the super plasticizer formulation was proportionately increased. For the above 3 concrete mixes the amount of the differential actives whose ratio matters the most of Diethylene glycol: Jeffamine D-230: Potassium sodium tartarate have been kept fixed as per the target RMC (ready mix concrete) required, together with the desired drying shrinkage and the permeability reduction of the concrete, wherein it shown as per Table 4 that when the ratio is violated the desired attributes could not be attained.

The manufacturing process is facile and cost intensive that does not involve any special process neither any usage of any ingredients and the processing of final formulation mix involves simple blending of components employed in selective amounts in a high speed mixer with variable speed drive at rpm ranging from around 20- 40.

According to another preferred aspect of the present invention there is provided said superplasticizer formulation comprising liquid additive that reduces drying shrinkage including a select class of glycols adapted for reducing the surface tension of water in concrete mix thereby reducing the stress exerted on the capillary walls by the water movement, caused due to evaporation of surface water. Apart from this, said liquid additive enables providing resistant to chloride ion penetration and makes the concrete impermeable via crystal growth mechanism as a result of reaction with hydration product of cement hydration.

It is thus made possible by way of the present invention to provide for said superplasticizer formulation that would preferably involve a single pack formulation which would adequately meet the functionalities of not only a superplasticizer, but would also reduce water permeability, reduce dry shrinkage and resistance to corrosion of rebar thereby serving a solution to all prior hurdles leading to advantageous aspects. Advantageously, also thus enables a single product solution that enhances at least four different aspects of concrete.

,CLAIMS:We Claim:

1. A single pack superplasticizer formulation comprising a synergistic combination of Diethylene glycol, Potassium sodium tartarate, Polyether diamine incorporated in amino alcohol free blend of polycarboxylate ether mix, Sodium ligno sulfonate, Sodium gluconate, suitable for correcting multiple concrete defects thereby enhancing durability of concrete.

2. The single pack superplasticizer formulation as claimed in claim 1 wherein said Diethylene glycol, Polyether diamine of average mol. wt. about 230 and Potassium sodium tartarate is incorporated in the ratio of Diethylene glycol: Polyether diamine: Potassium sodium tartarate:: 0.5-3.0: 0.5-3.0: 0.05-0.3 in said formulation that is stable for at least 12 months/years without any loss of stability corresponding to efficiency.

3. The single pack superplasticizer formulation as claimed in claims 1 or 2 wherein said polycarboxylate ether (PCE) mix comprises water reducer polycarboxylate ether, slump retainer polycarboxylate ether, and defoamer polycarboxylate ether that differs based on the mol.wt.,
Wherein water reducer PCE is obtained of polymerization of methycrylic acid and vinyl polyethylene glycol VPEG-2400, said water reducer PCE having weight average molecular weight (Mw) ˜20,000;
Wherein said slump retainer PCE is obtained of polymerization of methycrylic acid, 2-hydroxy propyl acrylate and vinyl polyethylene glycol VPEG-2400, said slump retainer PCE having weight Average Molecular Weight (Mw)˜25,000;

Wherein said defoamer PCE is a fatty acid ester such as stearic acid ester based non-ionic surfactant in combination with glycol.

4. The single pack superplasticizer formulation as claimed in claims 1-3 wherein said formulation comprises (a) water reducer Polycarboxylate ether in the levels of 10 to 60 wt.%;
(b) slump retainer Polycarboxylate ether in the levels of 8 to 40 wt.%;
(c) defoamer Polycarboxylate Ether in the levels of 0.01-0.2 wt.%;
(d) Sodium lingo sulfonate: 0.5-4 wt.%;
(e) Sodium gluconate: 3-10 wt.%;
(f) Diethylene glycol: 0.5-3.0 wt.%;
(g) Potassium sodium tartarate: 0.05-0.3 wt.%;
(h) Polyether amine (preferably Jeffamine D 230) of that is a difunctional, primary amine with an average molecular weight of about 230: 0.5-3.0 wt.%.

5. The single pack superplasticizer formulation as claimed in claims 1-4 advantageously poised as a single pack synergistic superplasticizer formulation free of involvement of multiple mixtures at the site of application depending on different type of concrete requiring overall costing including inventory management and hassle of involving multiple products and is adapted for combined functionality of superplasticizer, drying shrinkage reducer, water impermeability and corrosion inhibitor of casted concrete favouring upto 42.11% reduction in drying shrinkage, 21% reduction in chloride ion penetration and upto 49.6% reduction in water permeability.

6. A process to provide a single pack superplasticizer formulation as claimed in claims 1-5 comprising the steps of simple blending said ingredients in a high speed mixer with variable speed drive at rpm ranging from around 20-40.

Dated this the 8th day of April, 2021 Anjan Sen
Of Anjan Sen and Associates
(Applicants Agent)
IN/PA-199