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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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