Corrosion resistance of alkali-activated binary reinforced concrete based on natural volcanic pozzolan exposed to chlorides
| Autor: | Ana María Aguirre-Guerrero, Ruby Mejía de Gutiérrez, Rafael Andres Robayo-Salazar |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
0211 other engineering and technologies 02 engineering and technology Building and Construction Pozzolan Durability Chloride Corrosion law.invention Portland cement Mechanics of Materials law Ground granulated blast-furnace slag Electrical resistivity and conductivity 021105 building & construction Architecture medicine 021108 energy Composite material Safety Risk Reliability and Quality Polarization (electrochemistry) Civil and Structural Engineering medicine.drug |
| Zdroj: | Journal of Building Engineering. 33:101593 |
| ISSN: | 2352-7102 |
| DOI: | 10.1016/j.jobe.2020.101593 |
| Popis: | Alkali-activated concretes are being considered as an alternative environmentally friendly construction materials compared to the ordinary Portland cement. However, although these materials have reported mechanical properties comparable to those of OPC, the corrosion of reinforcing bars is a major durability issue that needs to be studied. This article studies the corrosion performance of an alkali-activated binary reinforced concrete (AABC) based on natural volcanic pozzolan (NP) and ground blast furnace slag (GBFS) exposed to chlorides ions. OPC concrete was used as reference material. To carry out the study, accelerated chloride ingress methods (impressed voltage, wet-dry cycles, and saltwater immersion (3.5% NaCl)) were used. Monitoring of the corrosive process was carried out using the techniques of half-cell potential, linear polarization resistance, polarization curves and curves of current intensity versus time. As complementary techniques, surface electrical resistivity and resistance to chloride ion penetration were evaluated. AABC showed higher resistance to chloride ion penetration compared to OPC concrete, a reduction of the charge passed up to 60% at 360 days of exposition. In general, the various accelerated chloride ingress techniques employed in the present research revealed that reinforcing steel embedded in AABCs have a higher resistance to corrosion compared to steel bars embedded in Portland cement (OPC)-based concrete. It should be noted that the B constant values obtained for AABC differ from the values commonly used in (OPC)-based concretes. In addition, the results indicate that the ranges of corrosion probability, such as half-cell potentials or corrosion currents, specified for OPC concretes should be checked for its application in alkali-activated concretes. |
| Databáze: | OpenAIRE |
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