The document discusses self-healing concrete that uses bacteria to repair cracks. It begins with an introduction that defines self-healing concrete as concrete that can heal itself when exposed to air and water by producing lime. It then discusses the necessity of self-healing concrete due to cracks over 2mm failing to heal naturally. The document outlines the working process, including the specific bacteria used - Bacillus species that are resistant to alkalinity and mechanical stress. It describes how the bacteria and chemical precursors activate to fill cracks with lime when water penetrates cracks. Testing has found the bacterial concrete is able to reduce permeability and remediate cracks. However, its production cost is higher than traditional concrete.

2. SCOPE OF PRESENTATION
i) INTRODUCTION
ii) NECESSITY
iii) WORKING PROCESS
iv) BACTERIA USED
v) WHAT SPECIAL PRESENT IN BIO CONCRETE
vi) TESTING
vii) APPLICATION OF HEALING
AGENTS
viii) ADVANTAGES AND
DISADVANTAGES
ix) CONCLUSION
x) REFERENCES

3. INTRODUCTION
DEFINITION:-
Self healing concrete is a
concrete which heals itself when it
comes in contact with air and water, it
produces lime on outer layer of
concrete.
 In most of the traditional
concrete mixture 20-30% of the
cement is left unhydrated.
 If cracking of the concrete
occurs, unreacted cement grains
may become exposed to moisture
penetrating the crack.
 In that case the hydration
process may start again and
hydration products may fill up and
heal the crack

4. NECESSITY
FORCES ON CONCRETE

5. Cracks less than 2mm can be auto fill by concrete;
But if cracks are more than 2mm then concrete itself
fail to heal itself thus openning passage to chemicals
and other corroding materials;
In bio-concrete if water is in the contact with the
concrete through the cracks the bacteria get activated
from its stage of dormancy .

6. WHAT
BACTERIA IS USED
 Most of the bacteria belongs to genus bacillus are fulfilling
the required criteria discussed above.
B. Cohnii
B. Filla
B. Pasteurii

7. BACTERIA
It contains an
outer layer of thick
wall, which resist
sunlight,chemical
exposure etc.

8. WHAT SPECIAL PRESENT IN BIO CONCRETE
• There are two things
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.

10. LIME FILLED IN CRACKS

12. TESTING ON BACTERIAL CONCRETE

13. RESULTS:-
In 2011, Henk Jonkers and his team found the above result by
testing on Bio concrete.

14. APPLICATION OF HEALING AGENTS
 BY DIRECT APPLICATION
The bacteria and the
chemical precursor
(calcium lactate) are added
directly while making
the concrete.
 ENCAPSULATION LWA
a) The part of the coarse aggregate is replaced
by the light weight aggregate (LWA), which is
impregnated with twice the calcium lactate solution
and the spores of the bacteria.
b) After impregnation the clay particles with
6% healing agents and the concrete is made.

15. Advantages and disadvatages of bacterial concrete:-
ADVANTAGES
Reduction in
permiability of
concrete
Microbial concrete in
crack remediation

16. Cost of bacterial concrete is
double than conventional
concrete
Growth of bacteria is not good
in any atmosphere and media
Design of mix concrete with
bacteria there is no available in any
IS code or other code

17. Conclusion of the S.H.B.C. Strategy
• It prevents the infrastructure crisis;
• Practical and Operationally Achievable;
• Marketable and profitable;
• Diminishes life-cycle costs;
• Is economical for the consumers.

18. References:-
• Use of bacteria to repair cracks in concrete by Kim Van Tittelboom a, Nele
De Belie a,*, Willem De Muyncka, b, Willy Verstraete b., 2008.
• Gollapudi et al., 1995; Stocks-Fischer et al., 1999; Bachmeier et al., 2002;
Dick et al., 2006; Rodriguez-Navarro et al., 2003.
• RafatSiddique, NavneetKaurChahal, “Effect of ureolytic bacteria on concrete
properties”, Construction and Building Materials 25 (2011) 3791–3801.
• Abo-El-Enein, Ali, FatmaTalkhan, Abdel-Gawwad, “Application of microbial
biocementation to improve the physico-mechanica properties of cement
mortar”, Housing and Building National Research Center (2013).

19. References:-
• H.M. Jonkers, A. Thijssen, O. Copuroglu, E. Schlangen, Application of
bacteria as self-healing agent for the development of sustainable concrete,
Proceedings of the 1st International Conference on BioGeoCivil
Engineering, 23–25 June 2008, Delft, The Netherlands.
• K. Santhosh, S.K. Ramachandran, V. Ramakrishnan, S.S. Bang,
Remediation of concrete using microorganisms, American Concrete Institute
Materials Journal 98 (2001) 3–9.
• Reinhardt, H.-W.; Jooss, M. Permeability and self-healing of cracked
concrete as a function of temperature and crack width. Cem. Concr. Res.
2003, 33, 981–985.