Presentation SHC.pptx on self healing concrete

Self healing concrete ppt

1. Self Healing Concrete Concrete that Heals Itself : Building a Resilient Future Presented by : Sarthak Rathi Branch : Civil Engineering Roll no : 2000290000040

2. Content INTRODUCTION WHAT IS SELF HEALING CONCRETE WHAT BACTERIA IS USED WORKING PROCESS HOW HEALING AGENTS ARE APPLIED TESTING ON SHC ADVANTAGES DISADVANTAGES APPLICATION CONCLUSION

3. Introduction Cracking in concrete is a main concern throughout the world because it cause loss of strength of structure with time. Formation of crack may lead to leakage problems, causing deterioration of the concrete or corrosion of embedded steel reinforcement . Problem leads to Development of :- A bacteria-based self healing concrete to extend the service life Self Healing concrete is special material which heals itself when it`s exposed to air & moisture present in the atmosphere . In most of the traditional concrete mixtures 20–30% of cement is left unhydrated . During cracking unreacted cement grains may exposed to moisture penetrating the cracks If SHC used the hydration process may start again & cracks Heals by itself .

4. Origins :- In 1877 , Ferdinand Cohn Claimed that with a Bacteria known as “ Genus Bacillus” concrete could be healed . Further:- Henk Jonkers, Delft University of Technology microbiologist Pioneered self-healing concrete development Neither land Researcher focused on integrating bacteria into concrete Bacteria lay dormant( for max 200 years) until cracks appear Activation triggers limestone production, filling cracks Significantly advances concrete durability Potential to extend lifespan of structures

5. Bacteria Used & Mixing Bacillus Cohni Bacillus Filla Bacillus Pasteurii DSM33

6. Mixing :- Cement used :- 43 Grade OPC or 53 Grade OPC Fine & Coarse Aggregates Organic Bacteria Spores While Mixing one precaution is taken that Bacteria & Cement are not allowed to mix together with the help of Clay Pallets . As High alkalinity in cement can harm or kill bacteria before they're added to the concrete. Mixed Together

7.   Working :- Self Healing Concrete is a product that will biologically produce limestone to heal cracks that appears on the surface of concrete structures . In SHC water seeps through the cracks, the bacteria get activated from its stage of dormancy and starts to feed on calcium lactate producing calcium carbonate, that acts as a healing material. Specially Selected Bacteria type along with Calcium Lactate :- ( Food Source For Bacteria ) Nitrogen & Phosphorus :- (Growth & Survival ) Were added during mixing . Cracks less than 0.2mm can be auto fill by healing . Ca(C3H5O2)2 +7O2 CaCO3 + 5CO2 +5H2O (Calcium Lactate) (Lime) (Calcite)

8. Before Healing After Healing

9. HOW HEALING AGENTS ARE APPLIED There are two Methods :- By Direct Application ( Smaller Cracks <0.2mm ) By Encapsulation ( 0.2mm < Larger Cracks < 1mm) Distribution Direct application ensures even distribution of bacteria throughout the concrete mix. While Encapsulation localizes and protects the bacteria in capsules or coatings, leading to controlled release. Activation In direct application, bacteria are immediately exposed to the concrete environment upon mixing. While Encapsulation keeps bacteria protected until triggered by crack formation, delaying their activation. Protection Encapsulation shields bacteria from harsh concrete conditions until activated by moisture ingress. Directly applied bacteria are exposed to the concrete's alkaline environment from the start, potentially impacting their initial viability.

10. In 2011, H.M. Jonkers does the case study on SHC A small part of a structure is built with SHC material and observed for 3-5 years . Structures were fitted with SHC panels and others with conventional concrete . Results shows that cracks healed well and fast in SHC panels . Latest Test Results Shows that SHC may also be use in Corrosion Resistance in Marine Environments Extreme weather Conditions Water Retaining Structures

11. REAL WORLD APPLICATIONS

12. Advantages & Disadvantages Advantage :- Helps to fill the cracks. Compressive strength of concrete is increased Reduction in permeability of concrete. Helps to reduce maintenance and repair. Reduction in corrosion of reinforced concrete Disadvantages :- For 28 Days (M20) Conventional concrete Self Healing Concrete Compressive strength (MPa) 28.8 32.74 Tensile Strength (MPa) 3.26 3.73 Cost of self healing concrete is double than traditional concrete. Skilled labour is required. There is no IS code or other code available. Availability Of Living Genetic Materials

13. Conclusion SHC appears to much more efficient than usual concrete as its crack resistance Eco Friendly Material Which Protects RCC From Corrosion & Heals Autonomously . Prevents Water Percolation in RCC . Reduce Carbon Footprint & enhance Structure Life. It’s an Ongoing Latest Research Project.

14. References:- J.Y.Wang,H.Soens,W.Verstraete,N.De Belie, “Selfhealing concrete by use of microencapsulated bacterial spores”, Cement and Concrete Research, Volume 56, February 2014, Pages 139–152 . Kim Van Tittelboom, Nele De Belie,Willem De Muynck, Willy Verstraete, “Use of bacteria to repair cracks in concrete”, Cement and Concrete Research, Volume 40, Issue 1, January 2010, Pages 157–166 . https://www.tudelft.nl/en/ https://www.re-thinkingthefuture.com/ https://www.forbes.com/

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