Perspective Chapter: Pore Structure Evolution of Cement and Concrete Induced by CO<sub>2</sub> Carbonation
<p id="p1">This chapter explores the profound impact of CO<sub>2</sub> carbonation on the pore structure of cement and concrete. Carbonation, resulting from the reaction of CO<sub>2</sub> with calcium hydroxide and calcium silicate hydrate in cement, is a complex process that affects the durability...
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| Main Authors: | , , |
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| Format: | Book Chapter |
| Language: | English |
| Published: |
IntechOpen
2024
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| Subjects: | |
| Online Access: | https://www.intechopen.com/chapters/1162008 |
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| Summary: | <p id="p1">This chapter explores the profound impact of CO<sub>2</sub> carbonation on the pore structure of cement and concrete. Carbonation, resulting from the reaction of CO<sub>2</sub> with calcium hydroxide and calcium silicate hydrate in cement, is a complex process that affects the durability and performance of cement-based materials. In this chapter, the changes in pore structure of cement and concrete induced by carbonation are examined. Under low pressure CO<sub>2</sub>, cement carbonation leads to the formation of dense carbonation regions. For wellbore cement exposed to high pressure and high concentration of CO<sub>2</sub>, a calcite precipitation layer with very low porosity is formed in cement, and two highly porous layers due to dissolution of calcite and cement hydration products are formed at both sides of the calcite precipitation layer. For concrete exposed to atmospheric pressure CO<sub>2</sub>, carbonation causes hydration products to form CaCO<sub>3</sub> and precipitate in pores. Different from wellbore cement, no distinct calcite precipitation layer is formed in concrete. However, for concrete exposed to 1 MPa CO<sub>2</sub>, excessive accumulation of CaCO<sub>3</sub> eventually leads to expansion and cracking of pores, which causes the compressive strength of concrete to decrease after reaching the peak.</p> |
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| ISBN: | 978-0-85466-368-2 |
| DOI: | 10.5772/intechopen.1005097 |