How well do you know the durability and carbonation of concrete structures?

Questions and Answers

Qu'est-ce qui est important pour réduire le besoin en ressources naturelles dans la construction de structures en béton?

La durabilité des structures en béton

Comment a évolué la durée de vie des structures en béton depuis les années 1960?

De 25 ans à 100-300 ans

Qu'est-ce qui détermine la durabilité des structures en béton?

Des phénomènes chimiques, mécaniques et physiques

Quel est le pH du béton frais?

<p>13</p> Signup and view all the answers

Qu'est-ce que la passivation?

<p>La création d'une couche protectrice Fe2O3CaO sur l'acier en contact avec les silicates de calcium et un pH élevé</p> Signup and view all the answers

Study Notes

Durability of concrete structures is important for reducing the need for natural resources in construction.
The lifespan of concrete structures has increased from 25 years in the 1960s to 100-300 years currently.
Durability depends on chemical, mechanical, and physical phenomena, including carbonation and chloride ion penetration.
Fresh concrete has a strongly basic pH of 13, protecting steel reinforcement.
Passivation creates a protective Fe2O3CaO layer on steel in contact with calcium silicates and high pH.
Carbonation by CO2 in the air is a natural process that is not harmful to concrete.
Carbonation begins with the dissolution of alkaline bases in the interstitial aqueous solution of concrete.
Carbonation rate is influenced by relative humidity, concentration of CO2, and temperature.
Carbonation depth and kinetics depend on the composition, porous structure, and exposure class of the concrete.
The thickness of the carbonated layer increases proportionally to the square root of time for typical concrete.