Corrosion testing on steel reinforced XD3 concrete samples prepared with a green inhibitor and two different superplasticizers

Abstract

In recent years, the use of corrosion inhibitors in producing high-performance steel reinforced concrete structures has increased significantly to minimize the chloride and sulfate attacks. However, most inhibitors available in the market are toxic to the environment. Hence, one objective of the present investigation was to test a novel, eco-friendly, so-called green inhibitor extracted from a fruit waste (orange peel), and its effects were studied on the compression strength of the XD3 type concrete samples. The inhibitor was added to the concrete mix in concentrations of 1% and 3% by weight of cement in addition to two different superplasticizers (Mapei Dynamon SR 31, Budapest, Hungary and Oxydtron, Hungary). The test results on steel reinforced samples immersed in 3.5 wt% NaCl aqueous solutions at room temperature showed promising corrosion mitigating effects just after 6 months testing period. The lower corrosion currents (i.e., better corrosion resistance) after 6 months immersion were observed when the samples contained both green inhibitor and Oxydtron superplasticizer, especially with sample C2 (in this case 3% green inhibitor was added to the mixture of cement + Oxydtron superplasticizer). K E Y W O R D Scorrosion rate, electrochemical polarisation, green inhibitor, reinforced concrete, superplasticizers

Analysis of corrosion rate, inhibition efficiency, and economic cost of XD3 reinforced concrete related to inhibitor and plasticiser types

“…To melt snow or stop it from building up on roads and bridges, several countries, including the United States, Canada, and Europe, use salt. Although this technology has advantages, it has a detrimental impact on steel structures because chloride ions attack steel and gradually remove the passive protective layer of steel, which causes local corrosion [12][13][14][15][16][17][18][19]. According to figure 1, an electrochemical mechanism accounts for how well steel reinforcement resists corrosion.…”

Studying chloride ions and corrosion properties of reinforced concrete with a green inhibitor and plasticizers

“…The corrosion process transforms steel into rust, leading to (a) area reduction of the reinforcement bars and (b) volume expansion that generates splitting stresses in the concrete, which may crack and spall the concrete cover and affect the bond-slip between reinforcement and concrete. [1][2][3][4][5][6][7][8][9] The phenomenon of corrosion in steel reinforcement is an electrochemical process consisting of two half-cell reactions as shown also in Figure 1, which represent the anodic oxidation of iron and the cathodic reduction of oxygen. Both of these reactions happen simultaneously and are necessary for the continuation of the corrosion process.…”

“…And, when the concrete structures becomes and has been exposed to such chemically aggressive agents such as chloride ions, originating either from deicing salts or marine environment or chloride contaminated aggregates, the diffusion of chloride ions through the porosities and cracks of concrete, the protective passive stratum of steel will be locally destroyed and so the unprotected steel areas can and will start dissolve. The corrosion process transforms steel into rust, leading to (a) area reduction of the reinforcement bars and (b) volume expansion that generates splitting stresses in the concrete, which may crack and spall the concrete cover and affect the bond‐slip between reinforcement and concrete 1–9 . The phenomenon of corrosion in steel reinforcement is an electrochemical process consisting of two half‐cell reactions as shown also in Figure 1, which represent the anodic oxidation of iron and the cathodic reduction of oxygen.…”

Investigations on the resistivity of XD3 reinforced concrete for chloride ions and corrosion with calcium nitrate inhibitor and superplasticizers

“…W krajach europejskich i w Stanach Zjednoczonych oraz Kanadzie, kiedy w okresie zimowym powstaje lód głównie na mostach, stosuje się sól do jego stopienia. W związku z tym, jeżeli konstrukcje betonowe zostają wystawione na działanie tak agresywnego środowiska jakim są jony chlorkowe, albo z soli odladzających, albo w środowisku nadmorskim, lub w końcu z powodu zanieczyszczonego chlorkami kruszywa, zabezpieczająca warstewka pasywacyjna na stali zostanie w niektórych obszarach zniszczona i rozpoczyna się lokalna korozja stali (3)(4)(5)(6)(7).…”

“…In countries like the United States, Canada, and Europe, when ice accumulates on bridges during cold weather, salt is usually used to melt the ice. And, when the concrete structures become and have been exposed to such chemically aggressive agents as chloride ions, originating either from deicing salts or marine environment, or chloride contaminated aggregates, in presence of chloride, the protective passive layer of steel will be locally destroyed and the unprotected steel areas can and will start dissolve (3)(4)(5)(6)(7).…”