Effect of Metakaolin on Performance of M40 Grade Concrete in Marine Environment

Abstract

Nowadays maintaining durable concrete structures in a salt water environment is found to be
difficult. Deterioration of structures is due to gradual penetration of salts and the subsequent
formation of expansive and leachable compounds which ultimately corrodes the
reinforcement and makes the structures fatigue. It is found that the setting time, compressive
strength depends on the reaction between cement and water which eventually results in
softening of concrete. This paper describes the effect of metakaolin on compressive strength,
splitting tensile test, modulus of elasticity and pH of concrete when salt water is used for
curing. Concrete specimens were cast for M40 grade of concrete for potable water and salt
water curing. Till 28 days concrete specimens were cured under salt water and potable
water. The test results showed better performance in compressive strength when replacement
of cement by metakaolin and cured with salt water is made. But the splitting strength test
values showed a slight decrease when cured with salt water. Optimisation in percentage
replacement of cement by metakaolin was made.