Best references that you can refer:- Costa A and Appleton j (1999), “ Chloride Penetration into Concrete in Marine Environment-Part 1 And Part-2.

1. CHLORIDE PENETRATION IN
MARINE ENVIRONMENT
REPRESENTING BY
SAGAR G S (USN 4SM14CV054)
UNDER THE GUIDENCE OF
Prof .PRAMOD P.S
DEPARTEMENT OF CIVIL ENGENEERING

2. Contents
Introduction of marine environment
 Chloride penetration
 durability (steel get corroded and cracking )
 Test to be assessed (chloride penetration)
 factors affecting at chloride penetration

3. Contents
Limits of chloride content in concrete (as per IS: 456-2000 )
 Concrete qualities under exposure conditions
 Diffusion coefficient variation
 Conclusion
 Reference

4. INTRODUCTION OF MARINE
ENVIRONMENT
• The water containing some chemical salts , in salt water (sea
water)exposed to surrounding environment mainly affect on the
structures exposed such environment are considered as marine
environment.
• The behavior of concrete structures in marine environment has
shown that the main cause of distress is reinforcement corrosion
due to chloride attack.

5. CHLORIDE PENETRATION
• In marine environment ,the service life of reinforced concrete structures
depends mainly on deterioration due to reinforcement corrosion .
• Two stages can be considered in this mechanism ;
• The initiation period corresponding to the critical chloride penetration up
to the level of reinforcement and the propagation period related to the
reinforcement corrosion and its detrimental effects on the structure .

6. • The penetration occurs either through the capillary pores or through cracks by
permeation ,capillary suction and diffusion.
• Chloride is quantified by Fick’s second law.
• d C / d t=D(d^2C/dx^2 )
• Where C(x , t) is the chloride penetration at depth x at time t and D is the diffusion
coefficient .Since diffusion is only one of the transport mechanisms involved in
chloride penetration. D is not a “true” diffusion coefficient and should be
considered as an “apparent” diffusion coefficient

7. Durability of concrete get decreased by
following reasons
• steel get corroded in the reinforced concrete
• small cracking occurs in concrete
• exposure condition of structure in marine environment.

8. Test to be assess for chloride penetration
• The evaluation of chloride penetration was based on the assessment of
the chloride content in samples taken at various depths in successive
exposure periods.
• For each period dust samples for each 5mm depth increment were taken
in two adjacent holes using a 20mm diameter drilling tool.
• The samples were analysed to measure the total chloride content (acid
soluble chloride)using a chloride ion selective electrode.

11. Diffusion coefficient variation
• Diffusion coefficient varies for different concrete mixes
• DC varies with time
• DC varies with different exposure conditions
• DC level higher with higher humidity level.

12. Time dependence of the surface chloride
concentration

13. Graph shows time dependence of the surface chloride
concentration

15. Fig. 4 – Time evolution of the critical
chloride penetration for
the various concrete mixes and exposure
conditions.

16. Fig. 4 shows that a cover of 40 mm is not enough to guarantee a
service life of 50 years except in the atmospheric exposure
conditions and for good concrete quality.
Table 4 presents the values of the minimum cover for the various
concrete mixes and exposure conditions required to guaranteeing an
initiation period of 50 years. This period can be used as the service
life if the propagation phase is neglected.

17. Conclusion
• Chloride penetration in concrete structure is highly dependent on
concrete quality and exposure condition
• Diffusion coefficients vary significantly with the concrete quality
and exposure conditions and show a clear time dependence.
• Fick’s second law is a good simulation of the chloride
concentration.

18. Conclusion
• The results also show that small increases of concrete cover leads
to a significant increase in the service life. Small covers (< 40 mm)
are not appropriate for any exposure condition in marine
environment.
• The experimental results show that the diffusion coefficients and
the surface chloride content have at rong time dependence.

19. References
• Costa A and Appleton j (1999), “ Chloride Penetration into Concrete in Marine
Environment-Part 1:Main Parameters Affecting the Penetration”, Materials and
Structures.vol.218.pp.252-259.
• IS:456-2000 code of practice for Plain and Reinforcement Indian standards, New
Delhi .
• Senthil Kumar and Naveenraj (2014) “Estimation of Marine Salts Behavior
Around the Bridge Structures” Vol.03,No.4,November 2014.

20. THANK YOU