Review on corrosion of steel reinforcement in alkali-activated concretes in chloride-containing environments

Tahri, W.; Xiang, Huimin; Shi, Caijun; Zhang, Zuhua

doi:10.1016/j.conbuildmat.2021.123484

Cited by 60 publications

(20 citation statements)

References 100 publications

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“…Analysis of the impedance spectra shows different impedance responses, depending on the exposure material (i.e., the different mortars) and the time of exposure (i.e., the number of wet/dry cycles), indicating the active/passive state of steel reinforcement and the different types of corrosion mechanisms that should be considered when interpreting the measured EIS values. The incomplete arc at high frequencies that is associated with bulk phenomena [ 24 , 45 , 46 , 47 ] is omitted from the interpretation; the discussion focuses on the parts measured at medium and low frequencies, when the system response represents faradaic processes. In the FA8 and MK2 mortars, the spectra obtained show that one time constant was prevalent at the beginning of the exposure.…”

Section: Discussionmentioning

confidence: 99%

“…Different electrochemical monitoring techniques are commonly used to study corrosion in concrete environments. One such technique used to characterize and quantify the processes of passivation and depassivation in steel used to reinforce concrete is electrochemical impedance spectroscopy (EIS) [ 22 ], which is also used to study the corrosion of steel in AAMs [ 14 , 23 , 24 ]. This non-destructive technique is useful for studying the electrochemical processes of inhomogeneous or multiphase materials.…”

Section: Introductionmentioning

confidence: 99%

“…This non-destructive technique is useful for studying the electrochemical processes of inhomogeneous or multiphase materials. The electrochemical impedance response measured, fitted by the appropriate equivalent circuit model, provides information regarding the electrical properties of the specimen tested, including the resistance and capacitance of the solid and liquid phases, as well as their interfacial properties [ 24 ]. However, the pore solution in AAMs can significantly differ from that of OPC-based cements in terms of its chemical, mineralogical, and redox characteristics [ 25 , 26 , 27 ], which can strongly influence all phases of the corrosion process.…”

Section: Introductionmentioning

confidence: 99%

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Characterizing Steel Corrosion in Different Alkali-Activated Mortars

et al. 2021

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Alkali-activated materials (AAMs) present a promising potential alternative to ordinary Portland cement (OPC). The service life of reinforced concrete structures depends greatly on the corrosion resistance of the steel used for reinforcement. Due to the wide range and diverse properties of AAMs, the corrosion processes of steel in these materials is still relatively unknown. Three different alkali-activated mortar mixes, based on fly ash, slag, or metakaolin, were prepared for this research. An ordinary carbon-steel reinforcing bar was installed in each of the mortar mixes. In order to study the corrosion properties of steel in the selected mortars, the specimens were exposed to a saline solution in wet/dry cycles for 17 weeks, and periodic electrochemical impedance spectroscopy (EIS) measurements were performed. The propagation of corrosion damage on the embedded steel bars was followed using X-ray computed microtomography (μXCT). Periodic EIS measurements of the AAMs showed different impedance response in individual AAMs. Moreover, these impedance responses also changed over the time of exposure. Interpretation of the results was based on visual and numerical analysis of the corrosion damages obtained by μXCT, which confirmed corrosion damage of varying type and extent on steel bars embedded in the tested AAMs.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Characterizing Steel Corrosion in Different Alkali-Activated Mortars

et al. 2021

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“…Compared with the traditional cement kiln collaborative disposal, the preparation of AACMs eliminates cement kiln, which in many cities is not available or is being shut down for its high carbon intensity and high pollution. Although reuse for AACMs preparation seems to be more environmentally friendly, there are still several issues, such as dioxins pollution, which cannot be reduced but only diluted in AACMs [ 13 ], high content chlorides, which corrode the steel reinforcement [ 15 ] and reduce the compressive strength of AACMs [ 16 ], et al…”

Section: Introductionmentioning

confidence: 99%

Preparation of Alkali Activated Cementitious Material by Upgraded Fly Ash from MSW Incineration

Chen

Zhao

Zuo

et al. 2022

IJERPH

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Utilization of municipal solid waste incineration fly ash (MSWI-FA) can avoid land occupation and environmental risks of landfill. In this paper, MSWI-FA was used to prepare alkali activated cementitious materials (AACMs) after two-step pretreatment. The ash calcination at 450 °C removed 93% of dioxins. The alkali washing with 0.2 g NaOH/g ash removed 89% of chlorine and retained almost 100% of calcium. The initial setting time of AACMs was too short to detect for 20% of MSWI-FA addition, and the prepared block had extensive cracks and expansion for CaClOH and CaSO4 inside. Alkaline washing pretreatment increased the initial setting time by longer than 3 min with 30% ash addition and eliminated the cracks and expansion. The significance of the factors for compressive strength followed the modulus of alkali activator > silica fume amount > alkaline washing MSWI fly ash (AW-MSWI-FA) amount. When the activator modulus was 1.2, 1.4 and 1.6, the blocks with 30% of AW-MSWI-FA had a compressive strength of up to 36.73, 32.61 and 16.06 MPa, meeting MU15 grade. The leaching test shows that these AACM blocks were not hazardous waste and almost no Zn, Cu, Cd, Pb, Ba, Ni, Be and Ag were released in the leaching solution.

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“…The external service environment of cement is complex and changeable, in which a variety of soluble salts interact to form a multi-salt concentration field, which has been proven to be able to change or even significantly change the diffusion coefficient of chloride ions and is in the seabed structure [17][18][19][20][21][22]. The cement of buildings is affected by the hydrostatic pressure field at the same time, thus forming a multi-field coupling environment, which makes the chloride ion transport mechanism in this environment worthy of further discussion [23][24][25][26][27].…”

Section: Introductionmentioning

confidence: 99%

Experimental Study and Simulation Calculation of the Chloride Resistance of Concrete under Multiple Factors

et al. 2021

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Cement is widely used in marine concrete, and its resistance to chloride ion corrosion has been widely considered. In this paper, based on a laboratory test, the influence of different hydrostatic pressures, coarse aggregate contents and w/c ratios on the chloride resistance performance is analyzed. Based on COMSOL finite element software, a two-dimensional cementitious materials model is established, and the simulation results are compared with the experimental results. The results show that the penetration depth of chloride ions in cement increases with the increase of the w/c ratio. Under the hydrostatic pressure of 0 MPa, when the w/c ratio is 0.35, the penetration depth of chloride ions is 7.4 mm, and the simulation result is 8.0 mm. When the w/c ratio is 0.45, the penetration depth of chloride ions is 9.3 mm, and the simulation result is 9.9 mm. When the w/c ratio is 0.55, the penetration depth of chloride ions is 12.9 mm, and the simulation result is 12.1 mm. Under different hydrostatic pressures, the penetration depth of chloride ions obviously changes, and with the increase in hydrostatic pressure, the penetration depth of chloride ions deepens. Under the w/c ratio of 0.35, when the hydrostatic pressure is 0.5 MPa, the penetration depth of chloride ions is 11.3 mm, and the simulation result is 12.1 mm. When the hydrostatic pressure is 1.0 MPa, the penetration depth of chloride ions is 16.2 mm, and the simulation result is 17.5 mm.

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Review on corrosion of steel reinforcement in alkali-activated concretes in chloride-containing environments

Cited by 60 publications

References 100 publications

Characterizing Steel Corrosion in Different Alkali-Activated Mortars

Characterizing Steel Corrosion in Different Alkali-Activated Mortars

Preparation of Alkali Activated Cementitious Material by Upgraded Fly Ash from MSW Incineration

Experimental Study and Simulation Calculation of the Chloride Resistance of Concrete under Multiple Factors

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