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BIO CONCRETE

PRESENTED BY:MOHAMMED FAAZILDEPT OF CIVIL ENGINEERINGALVAS INSTITUTE OF ENGINEERING AND TECHNOLOGY

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CONTENTS• Introduction• Bio Concrete• Constituents Of Bio Concrete• Mechanism• Application Of Healing Agent• Evaluation• Conclusion• References

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INTRODUCTION• Cracking in concrete is a main concern throughout the because it cause loss of strength of structure with Time.

• A environmental friendly solution is preferred i.e. biological concrete over other alternatives like epoxy resins which is non degradable.

• The bacteria based concrete is believed to remain hibernated within the concrete for up to 200 years. When cracks appear in a concrete structure and water starts to seep in through, the spores of the bacteria starts microbial activities on contact with the water and oxygen.

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BIO CONCRETE

• Its specially made to increase the lifespan or the

durability of concrete structure by the self healing

action of that concrete.

• Bio concrete is also called as BACTERIAL

CONCRETE or SELF HEALING CONCRETE.

• Its is a special type of concrete invented by a group of

microbiology researchers under the head of Henk

Jonkers.

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Constituents Of Bio Concrete

Mainly there are two components present in bio concrete :

• The special bacteria that has to resist the alkalinity and the

mechanical stress of concrete.

• The chemical precursor to activate the bacteria.

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MECHANISM• The cracks are formed on the surface of concrete due to

many reasons like shrinkage, Inadequate water for

hydration.

• But if cracks are more than .2mm then concrete itself fail

to heal itself thus opening passage to chemicals and other

corroding materials.

• In bio-concrete if water is in contact with the concrete

though the cracks the bacteria get activated from its stage

of dormancy and through its metabolic activities forms

calcite which further acts as a healing material .

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Continued..• The water is deliberately forced into the crack

and the precursor is activated.

• The activated precursor intern induces the bacteria to react with that precursor and form a base of calcium carbonate called as limestone.

• When the cracks are filled completely by the bacteria it again goes to the stage of dormancy.

• Again if in future if cracks get widen and the foreign particles tends to enter the cracks the bacteria get activated and thus heal the cracks. Thus acting as a long lasting healing agent.

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What is happening inside bio concrete (mechanism)

• The cracks are formed on the surface of concrete due to many reasons like shrinkage, Inadequate water for hydration …etc.

• The water is deliberately forced into the crack and the precursor is activated

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Continued…

• The activated precursor intern induces the bacteria to react with that precursor and form a base of calcium carbonate called as limestone

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Application Of Healing Agents

BY DIRECT APPLICATION• The bacteria and the chemical precursor(calcium lactate) are added

directly while making the concrete.ENCAPSULATION (Light Weight Aggregate) • The part of the coarse aggregate is replaced by the light weight

aggregate (LWA) , which is saturated with twice the calcium lactate

solution and spores of the bacteria.

• After saturation of the clay particles with 6% healing agents and

then concrete is made.

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Healing Agents

The bacteria which are used as the healing

agents are :• Acidithio bacillus sp.

• Mycobacterium sp.

• Proteobacteria

• Acidobacteria

• Actinobacteria

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Continued…

Acidithio bacillus sp.

Mycobacterium sp.

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Continued…

Proteobacteria Actinobacteria

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APPLICATION• From enhancement in durability of cementitius materials to

improvement in sand properties, from repair of limestone

monuments, sealing of concrete cracks to highly durable

bricks, microbial concrete has been successful in one and all.

• This new technology can provide ways for low cost and durable roads.

• High strength buildings with more bearing capacity.

• Long lasting river bank.

• Low cost durable housing.

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CONCLUSION • Microbial concrete technology has proved to be better than

many conventional technologies because of its eco- friendly nature, self-healing abilities and increase in durability of various building materials.

• Enhancement of compressive strength, reduction in permeability, water absorption, reinforced corrosion have been seen in various cementitious and stone materials.

• Cementation by this method is very easy and convenient for usage. This will soon provide the basis for high quality structures that will be cost effective and environmentally safe but, more work is required to improve the feasibility of this technology from both an economical and practical viewpoints.

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REFERENCES• International Journal of Materials Chemistry and Physics

Vol. 1, No. 1, 2015, pp. 11-19.

• Samudre MP, Mangulkar MN, Saptarshi SD, A review of

emerging way to enhance the durability and strength of

concrete structures: Microbial concrete, Intern J Innov Res Sci

Eng Tech. 3 (2014) 9311-9316.

• Google, google images, engineering trends.

• Ivanchev I, Research on cracks in reinforced concrete

elements by taking into account the experimentally

determined concrete and reinforcing steel mechanical

properties, Ind J App Res 5 (2015) 239-241.

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THANK YOU