Intrinsic Appliance of Bio-Cement to Intensify Properties of Concrete

Abstract

The present invention relates to an Intrinsic Appliance of Bio-Cement to Intensify Properties of Concrete. An object of the invention is to provide bio-cement composition to enhance properties of M40 grade of concrete. According to one aspect of the present invention, the Bio-Cement comprises 5% Bacillus Pasteurii and 95% urea and calcium lactate. The invention may also relate to any alternative methods or processes comprising any combination of the above or below features within the scope of the claims. The following presents a simplified summary of the disclosure in order to provide a basic understanding to the reader. This summary is not an extensive overview of the disclosure and it does not identify key or critical elements of the invention or delineate the scope of the invention. Its sole purpose is to present some concepts disclosed herein in a simplified form as a prelude to the more detailed description that is presented later. Accompanied Drawing [FIG. 1]

Specification

Description:[001] The present invention relates to construction materials, specifically bio-cement compositions designed to enhance the mechanical and durability properties of concrete. It focuses on bio-cement comprising Bacillus Pasteurii, urea, and calcium lactate, which produces calcium carbonate precipitate to fill micro-cracks in concrete, thereby improving its strength, durability, and longevity.
BACKGROUND OF THE INVENTION
[002] The following description provides the information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[003] Concrete is the most consumed construction material around the globe and contributes most of the civil structures. But due to its brittle nature and low tensile strength, cracking was unavoidable during its service time. To counteract tensile stresses reinforcement is provided in structures, so that cracks will not cause for collapse of structure directly. But fissures will accelerate degradation of concrete and also leads to failure, if aggressive chemicals enter inside, and corrode the steel bar through micro cracks progressed within the concrete, which also carry chemicals around steel bars. This will endanger safety of concrete structures. The formation of inevitable micro cracks as well as porosity inside concrete matrix are also another challenge for civil engineers. This is because the lifespan of cement-based structure is reduced owing to penetration of aggressive ions, which leads to destroying of concrete micro structure. This fact has also encouraged the civil engineering community to develop smart Bio-concrete, to fill micro cracks as well as concrete pores by microbial calcium carbonate in recent years. In particular, microbial calcium carbonate is precipitated and deposited inside the concrete matrix on the bacterial cells due to the chemical reactions between developed carbonate ions from metabolic activity and calcium ions are generated. This phenomenon is called micro biologically induced calcite precipitation (MICP).
[004] Micro cracks in concrete may develop in to large cracks which reduce service life of concrete structures, it is necessary to restrict the development of cracks at the early age of concrete. By thumb rule, each 1% increase in air content reduces strength of concrete by about 5%. In the early age of concrete as cement hydration progresses even a small reduction in total capillary porosity leads to considerable segmentation of large pores, which leads to reduction in size and number of channels of flow in cement mortar and further which leads to a reduction in the volume of large capillary cavities in the mortar will reduce the permeability of concrete.
Problem Statement:
[005] The present invention relates to application of Bio-cement to enhance properties of concrete. Specifically, the present invention relates to bio-cement comprising Bacillus pasteurii, urea and calcium lactate. Some of the inventions related to the investigation of the materials mentioned below.
[006] Abhishek Thakur, et.al., presented a review of different researches in the recent years on the use of bacterial concrete/bio-concrete for the enhancement in the durability, mechanical and permeation aspects of concrete. Contains studies on different bacteria's belongs to Bacillus & Sporocarcina groups, their isolation process, different approaches for addition of bacteria in concrete, their effects on compressive strength and water absorption properties of concrete and also the SEM and XRD analysis of concrete containing bacteria.
[007] Arpan Sharma, et.al., disclosed concrete's potential to increase its durability when exposed to very aggressive settings, as well as how durable concrete is when treated to a single degradation device, have all been investigated. To demonstrate the impact of the water/cement ratio on concrete durability, the durability of concrete on M30 and M60 grades of concrete was examined. In the acid attack test, two solutions were employed: one contained 5% HCl and the other included 5% H2SO4. After 7, 14, and 28 days, the compressive strength of a total of 12 specimens was evaluated. Based on the findings, it was noted that the specimens' strength decreased after being subjected to acid solution curing.
[008] Dr.G.Srinivasan, et.al.made an attempt to repair small fractures in concrete using bacteria from the bacillus family. To enhance the Microbiologically Induced Calcite Precipitation (MICP) process in concrete, different types of Bacillus family bacteria were injected externally. One soil bacteria, Bacillus.subtilis, has the ability to cause calcite to precipitate. In this instance, M20 grade of concrete was employed, and specimens were tested for compression utilizing CTM and NDT equipment after 28 days of curing. Concrete is intentionally cracked to a depth of less than one millimetre, and then bacterial culture-infused broth solution is injected along the fracture pattern. When UPV was examined utilising NDT technology after healing, a little improvement was discovered.
[009] Leena Chaurasia, et.al., investigated on incorporating ureolytic bacteria (B. megaterium, B. pasteurii) without substrate and non-ureolytic bacteria (B. cohnii) without chemical feed, the impact of bio mineralization in concrete was studied. The associated mechanism responsible for durability improvement was investigated in addition to the well-known MIP (microbially induced calcite precipitation). An improvement in mechanical characteristics, a decrease in water absorption (22%), a reduction in the amount of voids (24%) and a 26% increase in sulphate ion concentration at 180 days were all outcomes of the investigated mineralization process. X-ray diffraction and Fourier transform infrared spectroscopy results demonstrated an accelerated formation of hydrated products in the presence of bacteria. Thicken mineral deposition (microstructural modification) by bacteria at interfacial transition zone (ITZ) with Ca/Si = 1.5 was revealed by field emission scanning electron microscopy. In bacterial concrete, quantification by thermos gravimetric measurement revealed 16% more calcium silicate hydrate and 37% higher calcium hydroxide production. Finally, it is hypothesised that the extra hydration products formed by bacteria are the primary cause of the densified microstructure and subsequently improved macro characteristics of bacterial concrete.
[010] R.Laxmana Reddy, et.al., provided an overview of bio-cement and bio-concrete in general, as well as highlights the advantages of bio-cement over conventional agents and challenges to the successful commercialization of the microbiologically induced calcium carbonate precipitation (bio-cement) technology from laboratory (experimental) to field (commercial) scale. Reveals the potential, viability, and long-term effectiveness of bio minerals, and works to enhance the present mathematical models for the micro scale determination of MICP.
[011] R.M.Morsa, et.al., reported on during formation of dry concrete or mortar, bacterial spores, activation nutrients, and a carbon source are combined. A bacterial solution created with healing agent flakes of size 1-4 mm made up of Lactic acid derivatives, comprising calcium source, bacterial spores, and activation nutrients was applied to concrete prisms of size 40x40x160 mm,and the results were assessed after 3, 7, 14, 28, and 56 days. According to the results, adding a lactate derivative-based healing treatment comprising bacteria and activation nutrients to a commercial mortar will have little to no impact on how strong the mortar becomes. Oxygen consumption under aerobic circumstances and the restoration of crack water tightness beyond the autogenous healing capability in a permeability test serve as indicators of the agent's functionality. The environmental cost is covered in order to demonstrate the viability of using healing agents in a commercial setting, and an estimated competitive manufacturing cost is calculated.
[012] Shaik Mohammed Mansoor, et.al, examined how Bacillus.Subtilis affects the stability of fly ash that has been enhanced with bacteria. For M40 grade concrete, fly ash that has been enhanced with bacteria is substituted for cement in three different amounts (25%, 30%, and 35%). tests carried out after 28 days of curing the samples. According to test results, bacteria-enriched fly ash has improved the toughness of concrete. At 25% fly ash supplemented with bacteria, the maximum improvement in strength and resistance to chloride intrusion and water absorption was seen by RCPT. It is because of the accumulation of germs on cell surfaces within holes that concrete's durability has increased. The effect of Bacillus.Subtilis on the longevity of concrete produced by partially substituting fly ash for cement. Utilizing fly ash that has been treated with bacteria improves strength durability and early day strength.
[013] Sumit Joshi, et.al. investigated on the impact of nutrient media components, such as the carbon and nitrogen content of organic nutrients and Bacillus sp.CT5 bacterial cells, on the chemical and structural characteristics of concrete after 7,28 days was examined. Concrete's compressive strength decreased and cement paste's setting time was slowed down by the organic nutrition medium. The addition of bacterial culture to cement paste had no effect on the setting characteristics of the paste, nevertheless. With bacterial admixed and surface treated concrete specimens for M25 grade, a significant improvement in compressive strength and decrease in permeability was seen. In comparison to the control mix, the carbon and nitrogen content of the bacterially treated specimens was substantially higher. The samples taken from various depths of the concrete specimens, whether they were treated with bacteria or not, showed no discernible difference in pH. According to study findings, bacterial cells' biogenic precipitations of CaCO3 counterbalance the concrete's organic ingredients' tendency to make it weaker and improve its durability.
[014] Thus, there is a need to develop Bio-Cement composition to enhance properties of concrete.

SUMMARY OF THE PRESENT INVENTION
[015] The invention provides a bio-cement composition comprising:
Bio-Cement Composition: A mixture of 5% Bacillus Pasteurii bacteria with 95% urea and calcium lactate, which serves as a microbial nutrient source and facilitates calcite precipitation.
Enhanced Concrete Properties: When added to concrete in proportions of 0.5% to 2% by weight of cement, bio-cement fills micro-cracks and pores, reducing permeability and increasing compressive strength, split tensile strength, and flexural strength.
Application in M40 Grade Concrete: Bio-cement's application in M40 grade concrete has shown significant improvements, including an increase of 14.85% in compressive strength, 30.35% in split tensile strength, and 32.54% in flexural strength, compared to conventional concrete.
Biogenic Mineralization: This bio-cement induces microbial calcium carbonate precipitation (MICCP), which fills the pores and enhances the transition zone in concrete, leading to a denser microstructure.
[016] Other objects and advantages of the present invention will become apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments, in conjunction with the accompanying drawings, wherein like reference numerals have been used to designate like elements.
[017] In this respect, before explaining at least one object of the invention in detail, it is to be understood that the invention is not limited in its application to the details of set of rules and to the arrangements of the various models set forth in the following description or illustrated in the drawings. The invention is capable of other objects and of being practiced and carried out in various ways, according to the need of that industry. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
[018] These together with other objects of the invention, along with the various features of novelty which characterize the invention, are pointed out with particularity in the disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[019] The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
[020] Figures 1-2 represent various graphical results' diagrams of an Intrinsic Appliance of Bio-Cement to Intensify Properties of Concrete, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[021] While the present invention is described herein by way of example using embodiments and illustrative drawings, those skilled in the art will recognize that the invention is not limited to the embodiments of drawing or drawings described and are not intended to represent the scale of the various components. Further, some components that may form a part of the invention may not be illustrated in certain figures, for ease of illustration, and such omissions do not limit the embodiments outlined in any way. It should be understood that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the scope of the present invention as defined by the appended claims. As used throughout this description, the word "may" is used in a permissive sense (i.e. meaning having the potential to), rather than the mandatory sense, (i.e. meaning must). Further, the words "a" or "an" mean "at least one" and the word "plurality" means "one or more" unless otherwise mentioned. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. Language such as "including," "comprising," "having," "containing," or "involving," and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers or steps. Likewise, the term "comprising" is considered synonymous with the terms "including" or "containing" for applicable legal purposes. Any discussion of documents, acts, materials, devices, articles and the like is included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters form part of the prior art base or are common general knowledge in the field relevant to the present invention.
[022] In this disclosure, whenever a composition or an element or a group of elements is preceded with the transitional phrase "comprising", it is understood that we also contemplate the same composition, element or group of elements with transitional phrases "consisting of", "consisting", "selected from the group of consisting of, "including", or "is" preceding the recitation of the composition, element or group of elements and vice versa.
[023] The present invention is described hereinafter by various embodiments with reference to the accompanying drawings, wherein reference numerals used in the accompanying drawing correspond to the like elements throughout the description. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein. Rather, the embodiment is provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. In the following detailed description, numeric values and ranges are provided for various aspects of the implementations described. These values and ranges are to be treated as examples only and are not intended to limit the scope of the claims. In addition, a number of materials are identified as suitable for various facets of the implementations. These materials are to be treated as exemplary and are not intended to limit the scope of the invention.
[024] Bio-cementation is a process based on Microbial induced Calcium carbonate precipitation (MICCP) mechanism. Primary role of microorganism in carbonate precipitate is due to the ability to create an alkaline environment through physical activities. There are three main groups of micro bias that produce carbonate precipitate are(1)Photo synthetic microorganism(2) Sulphate reducing bacteria(3)Micro organism involved in Nitrogen cycle. By involving photo synthetic microbias utilize urea using urease or urea amidolyase enzyme, based on which it is possible to use microalgae as media to produce bio-cement through biocementation. The microbial urease enzyme catalyses the hydrolysis of urea in to Ammonium and carbonate. One mole of urea is hydrolysed in to one mole of ammonia and one mole of acid(1), which spontaneously hydrolyses to form an additional one mole of ammonia and carbonic acid (2).
Bio-cement: Bio-cement is the combination of 5%Bacillus.Pasteurii and 95% adjuvants like urease and lactose enzyme, This forms MICCP precipitate which forms fills the gel pores developed in the formation of C-S-H gel strengthens transition zone by forming precipitate around the aggregate.

Materials used: The following materials are used in the present invention:
Ordinary Portland cement (OPC),
Coarse Aggregate (10mm,12.5mm and 20mm),Fine aggregate(Natural river sand),
Bio-Cement (5%Bacilus.Pasteurii + 95%Urea and Calcium Lactate),
Fly Ash, GGBS,
PC60- Super plasticizer.
According to one embodiment of the invention, the results obtained from compressive strength of conventional concrete and bio-cement for different percentages, such as0.5%,1%.1.5% and 2% by weight of cement for M25 grade as shown in Table1:
Table 1: Compressive strength values for Conventional and Bio-concrete M25 grade.

Curing Period In days Conventional Concrete(MPa) Bio-concrete (MPa)
0.5% 1% 1.5% 2.0%
7 21.66 23.85 25.81 23.68 21.28
28 30.96 33.91 35.71 33.34 30.43
56 34.75 37.37 40.51 36.98 33.34

Mix design for M25,M40 and M60 was done, and for M60 grade Flyash, GGBS as admixtures, PC60 used as super plasticizer for M40 and M60 grades. From the values of experimental work 1% augmentation of Bio-cement to OPC gives good results,and the concrete thus formed named as Bio-concrete for further studies.According to one embodiment of the invention,the species Pasteurii belongs to the family of the Planococcaceae. This family is placed at the department of the firmicutes.The names sporocina.Pasteurii and Urobacillus.Pasteurii are used as synonyms. The cells of B.Pasteurii are rod-shaped.They are gram-positive.The diameter of the cells is between 0.5and-1.2μm in width and 1.3 to 4.0μm in length. They appearsingly or in pairs. S. Pasteurii, like all species of the genus, endospores. It does not perform photosynthesis .The metabolismis due to fermentation. It also shows growth under an aerobic conditions.The pH value for best growth is pH 9. S.Pasteurii is thus alkaliphilic, preferably high pH values.The optimum temperature for growth is 30°C.Further,Basillus.Pasteurii is one of the microorganisms whose bio-mineralization is intensively studied to enable technical applications based on their ability to produce calcium carbonate. The high activity of the urease formed during the substrate removal is advantageous, where by a large quantity of calcium carbonate can be formed as bio mineral if sufficient calciumions are present in the nutrient medium.It is also important that Bacillus.Pasteurii,as an alkaliphilic organism, tolerates the high pH values necessary for bio mineralization. B. Pasteurii is a bacterium with the ability to precipitate calcite and solidifys and given a calcium source and urea,through the process of microbiologically induced calcite precipitation(MICCP).B.Pasteurii--+ has been proposed to be used as an ecologically sound biological construction material.
Chemical reactions: Bio- cement when mixed with water reacts with each other and will form hydrated compounds. A grain of Bio-cement contains
5% Bacillus. Pasteurii + 95% Urea and Calcium Lactate.
CO(NH2)2+ H2O→NH2COOH+NH3
NH2COOH+H2O →NH3+H2CO3
Ammonium and carbonic acid will form bicarbonate and two moles of ammonium and hydroxide ions in water
2NH+2H2O→2NH+4+2OH−
H2CO3→HCO−3+H+
The production of hydroxide ions results in the increase of pH, which in turn can shift the bicarbonate equilibrium, resulting in the formation of carbonate ions
HCO−3+H++2NH+4+2OH−→ CO3−2+2NH+4+2H2O
The produced carbonate ions precipitate in the presence of calcium ions as calcium carbonate crystals.
Ca+2+CO3−2→CaCO3
Due to the addition of Bio-cement the reaction takes place was parallel to the hydration of cement.So that gel pores formed due to the conversion of ettringite to C-S-Hgel were filled with MICP.By this activity conversion of natural resources to construction materials lasts longer is therefore an ecological step.There reduction in the volume of large capillary voids in the paste matrix will reduce the permeability. This will be possible by the successful combination of MICP and C-S-H gel.The gradual loss of free water from the system as a result of the formation of hydration products,surface adsorption of poorlycrystalline products such as MICP, ettringite and C-S-H gel causes the paste to stiffen and finally to set and harden.
In the present invention, effect of nutrient components of media such as Carbon and Nitrogen content of organic nutrients (Urea& Calcium Lactate) and bacterial cells (Bacillus.Pasteurii) on the chemical and structural properties of concrete were carried out. In this concept, pores in concrete will be filled with Micro biologically induced Calcium Carbonate precipitate (MICP) at the initial stage before the formation of cracks. Biogenic precipitations of CaCO3 by bacterial cells counteractthe retarding effect of organic nutrients of concrete and enhance the strength and durability properly.
According to one embodiment of the invention,experimental work was performed to develop dense concrete, before the formation of cracks at the initial stage of formation of C-S-H gel. For this Bio-cement considered, which is combination of 5% Bacillus.Pasteurii + 95% Urea and Calcium Lactate. By the addition of Bio- cement, reaction takes place and form MICCP, which fills the pores formed at heearly age of concrete. Bio-cement in different percentages 0.5%, 1%, 1.5% and 2% as additive by weight of cement to M25 grade concrete. Investigations were executed to study the effect of behaviour of Bio-cement based on Compressive strength, Split tensile strength, Flexural strength, Sulphate attack, Water absorption & EDS for7,28 and 56days curing periods.Fromtheresults,1%ofBio-cementasoptimized.
For that optimized mix of Bio-concrete M25, M40 & M60 (OPC+FA+GGBS)grades of concrete, for curing periods 7, 28, 56, 90, 180, 270 and 360 days tests were made.The mechanical and durability properties as Sulphate attack, Acid attack, Sorptivity and RCPT. All the results were analyzed and empirical relation between Compressive strength and Flexural strength were also established. Simultaneously, NDT also carried by Ultrasonic pulse velocity and Rebound hammer value and empirical relation between Compressive strength and UPV generated for Bio-concrete and conventional concrete. The following tables shows the values of compressive strength, split tensile strength and flexural strength values of conventional concrete and Bio-concrete.
Table 2: Compressive strength values for Conventional and Bio-concrete for M40 grade.
Curing period 7days 28days 56days 90days
Conventional
concrete,N/mm2 32.88 49.29 53.83 56.69
Bio-concrete,
N/mm2 36.84 56.48 61.81 65.16
Table 3: Split Tensile Strength values for Conventional and Bio-concrete for M40 grade.
Curing period 7days 28days 56days 90days
Conventional
concrete,N/mm2 2.94 4.69 5.27 5.69
Bio-concrete,
N/mm2 3.89 6.56 7.28 7.72
.
Table 4: Flexural Strength values for Conventional and Bio-concrete for M40 grade.
Curing period 7days 28days 56days 90days
Conventional
concrete, N/mm2 3.81 5.89 6.51 6.96
Bio-concrete,
N/mm2 4.82 7.78 8.71 9.34

[025] It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-discussed embodiments may be used in combination with each other. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description.
[026] The benefits and advantages which may be provided by the present invention have been described above with regard to specific embodiments. These benefits and advantages, and any elements or limitations that may cause them to occur or to become more pronounced are not to be construed as critical, required, or essential features of any or all of the embodiments.
[027] While the present invention has been described with reference to particular embodiments, it should be understood that the embodiments are illustrative and that the scope of the invention is not limited to these embodiments. Many variations, modifications, additions and improvements to the embodiments described above are possible. It is contemplated that these variations, modifications, additions and improvements fall within the scope of the invention. 
, Claims:A composition of Bio-Cement to enhance properties of concrete, the Bio-Cement comprising:
A. 5% Bacillus Pasteurii;
B. 95% Urea and Calcium lactate.
C. The composition of Bio-Cement as claimed in claim 1, wherein the Bio-Cement is added in the range of 0.5% to 2% as additive by weight of cement to M40 grade concrete.
D. The composition of Bio-Cement as claimed in claim 1, where in the Bio- Cement forms MICCP precipitate which forms fills the gel pores developed in the formation.

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