The document discusses a seminar on bacterial concreting, a self-repairing bio-material designed to enhance the durability of concrete. It focuses on the use of micro-biologically induced calcite precipitation (MICP) through bacteria such as Bacillus species to fill cracks and prolong the lifespan of concrete structures. Practical applications and future prospects of bacterial concrete in construction are also outlined, highlighting its potential benefits and ongoing research efforts.

1. SEMINAR
ON
BACTERIAL CONCRETING-A self repairing bio-material
Guided by, Presented by,
Ms. SMITHA M S ABHIJITH SURESH
Assistant Professor S7 CE
Civil Department Roll No: 01
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2. INTRODUCTION
 Cracking of concrete is an inevitable phenomenon related to
durability.
 repairing of existing cracks has been a subject of research for
many years.
 In recent years, a bacteria based self healing concrete is being
developed to extend the service life.
 Synthetic polymers such as epoxy treatment etc. are currently
being used as filling agents.
 They are neither eco-friendly nor safe for human health.
 Hence the use of a biological repair technique or micro-
biologically induced calcite precipitation technique[MICP] in
concrete is focused,
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3. OBJECTIVES
 For studying the strength and regaing capacity of concrete with
different bacterial class.
 To study the durability of bacterial concrete.
 It’s resistance towards freeze thaw attack and sulphate attack.
 To study advantages and dis-advantages and possibilities of
application of MICP (Microorganism used for Calcium Carbonate
Precipitation in Concrete) in construction area.
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4. WHAT
IS
“ BACTERIAL CONCRETE ?”
 It is a special type of concreting.
 by a group of micro-biologically researchers under the head of
henk jonkers.
 It is also called as “ bio-concrete” or “self healing concrete.”
 It is mainly invented to increase the durability or lifespan of the
concrete.
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5. WHAT IS “MICP- TECHNIQUE?”
 It is a novel technique in remediating cracks and fissures in
concrete.
 It is done by utilizing micro-biologically induced calcite[CaCo3]
in normal concrete.
 It is pollution free and natural.
 It will acts as a microbial sealant through out the concrete.
 It comes under a broader category of science called “bio-
mineralization”.
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6. BIO-MINERALISATION
 It is a process by which living organisms form inorganic solids.
 “Bacillus pasteruii” is a common soil bacterium can induce the
precipitation of concrete.
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7. HOW DOES BACTERIA REMEDIATE
CRACKS?
-the chemical reaction process
 The cell surface is negative in charge.
 It draws cations including Ca2+ from the atmosphere to
deposit on the surface.

Thus the calcite is precipitated and eventually plug in the pores of
the concrete.
Ca2++ cell = cell- Ca2+
Cell - Ca2++Co3
2- = cell-CaCo3
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8. WHAT HAPPENING IN THE BACTERIAL
CONCRETE?
- mechanismof bacterial concrete
 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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9.  The activated precursor intern induces the bacteria to react with
that precursor and form a base of calcium carbonate called as
lime stone,
Ca2++ cell = cell- Ca2+
Cell - Ca2++Co3
2- = cell-CaCo3
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10. 10/28

11.  40X
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12.  some Pictures about bacterial concreting,
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13. TYPES OF BACTERIA USED
They are classified as the following ;
 Bacillus pasturii.
 Bacillus Subtiles.
 Bacillus Sphaericus.
 Bacillus Cohnii.
These can lie dormant within the concrete for several years.
B.Cohnii. B.pasturii. B.Sphaericus B.Subtiles.
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14. PRACTICAL USE
 The use of Self healing concrete has been very limited world
wide .
 The concept is still in developing stage & on the way to large
scale use.
 In India no use of this has been done.
 A group of professors in JNTU are researching on bacterial
concrete.
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15. FUTURE SCOPE
 Can be used in the construction of aircraft runways, bridges and
dams reducing the maintenance cost.
 Retaining wall construction.
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16. SCANNING ELECTRON MICROSCOPY
INVESTIGATION
 To give a visual documentation of the extent of mineral
precipitation in various regions with in the cement mortar.
 To characterize the micro-structure relationship relationship of the
precipitates and the filling materials.
 To confirm the elemental composition of the mineral precipitates.
 To identify the microscopic evidence supporting the participation
of bacteria in mineral precipitation.
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17. XRD ANALYSIS
-xraydiffraction analysis method
 XRD provides most definitive structural information.
 It use monochromatic beam for sample analysis.
 Single crystal diffraction mechanism is adopted in XRD analysis.
 XRD is based on indexing the patterns.
 Most effective in cubic specimens.
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18. MICRO-STRUCTURE EXAMINATIONS
 It is based on the micrograph obtained by scanning electron
microscopic analysis.
 From the micrograph, it is was investigated the growth of rod
shaped fabulous
deposition in concrete with bacteria.
 It also reveals the calcifying power of the different micro-
organisms and their interaction with concrete.
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19.  Magnified image of full grown calcite crystals with distinct and
sharp edges, found in the interior surface of the crack.
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20. ROAD SHAPED DEPOSITION ON
CONCRETE SURFACE
 Road shaped impressions, consistent with the dimensions of
B.pasteurii are spread around the calcite crystals, formed on the
surface of the specimens subjected to sulphate attack.
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21. DEVELOPING CALCITE CRYSTALS
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22. MAGNIFIED IMAGE OF CALCITE
CRYSTALS
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23. DURABILITY COMPARISON
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24. COMPRESSIVE STRENGTH
COMPARISON
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25. ADVANTAGES
Perpetual and expected cracking that occurs in every
concrete structure due to its brittle nature can be controlled.
Repairs without a human work crew.
Self-healing concrete also prevents the exposure of the
internal reinforcements.
It has made to extend the life span of a concrete structure
of any size, shape.
Material consumption reduced in form of cement.
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26. CONCLUSION
 It was found that all specimens with bacteria formed a layer of
calcite at the surface.
 There were improvements in impermeability and its resistance to
alkaline environment,sulphate attack, freeze and thaw etc.
 SEM method was used to document the role of bacteria in
improving the durability of concrete.
 B.subtiles was most effective microbiome for the crack
remediation as remediates easily and helps in gaining early
strength.
 Thus it can be concluded that presence of bacteria in concrete can
improve the strength and durability of concrete structure.
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27. REFERENCE
 Vijeth N Kashyap and Radhakrishna,a study on the effects of
bacteria on cement composites,356-360,2013
 M.V. Seshagiri Rao, V. Srinivasa Reddy, M. Hafsa, P. Veena and P.
Anusha,Bioengineered Concrete - A Sustainable Self-Healing
Construction Material,45-51,2013.
 Mayur Shantilal Vekariya, Prof. Jayeshkumar Pitroda, Bacterial
Concrete: New Era For Construction Industry, Volume 4 Issue 9-
Sep 2013
 www.Google.com
 www.ijret.org
 www.Wikipedia.org
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28. THANK YOU..
FOR LISTENING….
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