NATCON

The inhibition synergism of some plant extracts and common inorganic inhibitors to enhance
the corrosion control of the embedding steel bars in concrete“.

Financing entity: European Union (Ref. 892074 – H2020-MSCA-IF-2019)

Participants: Univ. Carlos III de Madrid

Coordinator : Francisco Velasco

Dates: Jan 2021- Jan 2022

Financing: 86.466 €


Summary:

Corrosion of reinforcements often limits the durability of reinforced concrete structures, because of chloride ions or as a result of carbonation. Corrosion of reinforcement has huge economic implications as well as social issues including endangering the safety of people who are working in industries. Corrosion inhibitors control the corrosion of steel reinforcements without significantly changing the concrete properties. The environmental toxicity of the synthesized corrosion inhibitors has resulted in the search for finding green corrosion inhibitors with lower amount of toxic compounds. The corrosion inhibitors extracted from the plant products are inexpensive, readily available and renewable. Most parts of plants such as leaf, fruits peel, etc., are rich of the compounds that give them the capability to be used as corrosion inhibitor for various substrates in different electrolytes. NATCON project aims to examine the synergistic effect of some plant extracts and common inorganic inhibitors to enhance the corrosion control of the embedding steel bars in concrete.

Objective:

The objective of NATCON is the development of synergistic organic natural inhibitors (from plants) and inorganic ones for construction (concrete) applications. NATCON has a clear novelty, as inhibitors prepared from plant extracts have been scarcely tested in strongly alkaline environments as those that can be found in the pores of concrete. More than synergy with traditional inorganic inhibitors (nitrites), NATCON has tried to evaluate the performance of natural inhibitors both in solution and in mortar.

Dissemination of results:

a) Papers published in Journal Citation Report (JCR) magazines.

R. Naderi, A. Bautista, F. Velasco, M. Soleimani, M. Pourfath. “Use of licorice plant extract for controlling corrosion of steel rebar in chloride-polluted concrete pore solution”. Journal of Molecular Liquids, 346 (2022), 117856. DOI: 10.1016/j.molliq.2021.117856

R. Naderi, A. Bautista, F. Velasco, M. Soleimani, M. Pourfath. “Green corrosion inhibition of the carbon steel reinforcement in the chloride-polluted simulated concrete pore solution by Urtica Dioica extract”

b) Presentations at conferences and seminars.

R. Naderi, F. Velasco, A. Bautista. “On the use of liquorice extract as corrosion inhibitor of steel in simulated concrete pore solutions”. EUROMAT 2021 (European Congress and Exhibition on Advanced Materials and Processes). 12-16 September 2021 (oral presentation)

R. Naderi, F. Velasco, A. Bautista. “Corrosion inhibition function of Urtica Dioica extract on the steel immersed in simulated concrete pore solutions”. Eurocorr 2021 (European Corrosion Congress). 20-24 September 2021 (oral presentation)

R. Naderi, F. Velasco, A. Bautista. “Inhibition synergism between liquorice extract and nitrites: application on steel reinforcements in solution”. ICBMM 2021 (5th International Conference on Building Materials and Materials Engineering). 24-26 September 2021 (oral presentation)

Some results:

Analysis through electrochemical impedance spectroscopy (EIS) of steel immersed in solutions containing plant extracts, and simulating those contained in concrete pores

Inhibition efficency of solutions containing plant extracts, and simulating those contained in concrete pores

FTIR analysis of a plant extract and a steel immersed in solutions containing this plant extract

Density and porosity of mortars with plant extract in their composition

Final report:

For more information, or access to the final project report, contact fvelasco@ing.uc3m.es