The use of new binders for structural concrete raises questions about the durability of reinforced concrete structures. Calcium sulfoaluminate cement (CSA) has become in recent years an environmental-friendly alternative to ordinary Portland cement (OPC), but the protection capacity of concrete in relation to the corrosion of embedded steel reinforcement needs to be studied. This paper describes a study on the corrosion behaviour of carbon steel embedded in concrete made with CSA-based binders. It was shown that the pore solution of sulfoaluminate concrete was enough alkaline to passivate embedded carbon steel rebars. Compared to traditional Portland and Portland-limestone cements, CSA cement led to higher carbonation rate of concrete, but to lower corrosion rate of steel in carbonated concrete, likely due to higher electrical resistivity. Corrosion rate was negligible up to 95% RH at 20°C. Blending of CSA and OPC cements improved steel passivity and concrete resistance to carbonation.

Corrosion resistance of steel embedded in sulfualuminate-based binders

Maddalena Carsana;Luca Bertolini
2018-01-01

Abstract

The use of new binders for structural concrete raises questions about the durability of reinforced concrete structures. Calcium sulfoaluminate cement (CSA) has become in recent years an environmental-friendly alternative to ordinary Portland cement (OPC), but the protection capacity of concrete in relation to the corrosion of embedded steel reinforcement needs to be studied. This paper describes a study on the corrosion behaviour of carbon steel embedded in concrete made with CSA-based binders. It was shown that the pore solution of sulfoaluminate concrete was enough alkaline to passivate embedded carbon steel rebars. Compared to traditional Portland and Portland-limestone cements, CSA cement led to higher carbonation rate of concrete, but to lower corrosion rate of steel in carbonated concrete, likely due to higher electrical resistivity. Corrosion rate was negligible up to 95% RH at 20°C. Blending of CSA and OPC cements improved steel passivity and concrete resistance to carbonation.
2018
Sulfoaluminate cement, Passivation, Corrosion, Carbonation, Pore solution
File in questo prodotto:
File Dimensione Formato  
2018_C&CC-CSA.pdf

Accesso riservato

Descrizione: Articolo CSA
: Publisher’s version
Dimensione 9.29 MB
Formato Adobe PDF
9.29 MB Adobe PDF   Visualizza/Apri
11311-1099693_Carsana.pdf

accesso aperto

: Post-Print (DRAFT o Author’s Accepted Manuscript-AAM)
Dimensione 400.08 kB
Formato Adobe PDF
400.08 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11311/1099693
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 36
  • ???jsp.display-item.citation.isi??? 26
social impact