Repair materials system for chloride-induced corrosion of reinforcing bars

Tatematsu, Hidenobu; Sasaki, Takahiko

doi:10.1016/s0958-9465(01)00059-2

Cited by 51 publications

(28 citation statements)

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“…Chemically synthesized hydrocalmite behaves as an anion exchanger: adsorbing corrosive chloride ions and releasing corrosion-inhibiting nitrite anions. [7] Despite considerable efforts devoted to the development of new, complex anticorrosion systems, practically no single solution is able to fulfill the requirements of sufficient corrosion protection while avoiding chromates in the coating, especially in the case of aluminum alloys used for aerospace applications.The recently developed technology of layer-by-layer (LbL) deposition [8] of oppositely charged species (polyelectrolytes, nanoparticles, enzymes, dendrimers) from their solutions on the substrate surface represents an interesting approach to prepare reservoirs with regulated storage/release properties assembled with nanometer-thickness precision. LbL coatings are of practical interest in photonics (optical filters, luminescent coatings), [9] electrocatalysis (electrodes for DNA transfer, enzyme-catalyzed oxidation), [10] as membranes, [11] and chemical reactors.…”

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confidence: 99%

Layer‐by‐Layer Assembled Nanocontainers for Self‐Healing Corrosion Protection

et al. 2006

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The corrosion of metals is one of the main destructive processes that leads to huge economic losses. Polymer coating systems are normally applied on a metal surface to provide a dense barrier against the corrosive species in order to protect metal structures from corrosive attack. When the barrier is damaged and the corrosive agents penetrate to the metal surface the coating system can not stop the corrosion process. The most effective solution so far for designing anticorrosion coatings for active protection of metals is to employ chromate-containing conversion coatings.[1] However, hexavalent chromium species are responsible for several diseases, including DNA damage and cancer, [2] which is the main reason for banning Cr 6+ -containing anticorrosion coatings in Europe from 2007. The deposition of thin inorganic or hybrid films on metallic surfaces has been suggested as a pretreatment to provide an additional barrier against the corrosion species and mainly to improve adhesion between the metal and polymer coating system.[3] The films are usually deposited by the plasma polymerization technique or the sol-gel route. Sol-gel-derived thin films that contain either inorganic (phosphates, vanadates, borates, and cerium and molybdenum compounds) or organic (phenylphosphonic acid, mercaptobenzothiazole, mercaptobenzoimidazole, triazole) inhibitors are investigated as substitutes for chromates. [3a-e] Among them, the highest activity is shown for sol-gel coatings with a cerium dopant of a critical concentration in the 0.2-0.6 wt % range. However, the negative effect of the free inhibitor occluded in the sol-gel matrix on the stability of the protective film is observed for all types of inhibitors (for instance, a higher concentration of Ce leads to the formation of microholes in the sol-gel film [3f] ). This shortcoming calls for the development of nanometer-scale reservoirs to isolate an inhibitor inside and prevent its direct interaction with the sol-gel matrix. Nanoreservoirs should be homogeneously distributed in the film matrix and should possess controlled and corrosion-stimulated inhibitor release to cure corrosion defects.Mixed-oxide nanoparticles (e.g. ZrO 2 /CeO 2 ), [4] b-cyclodextrin-inhibitor complexes, [3c] hollow polypropylene fibers, [5] and conducting polyaniline [6] have been explored as prospective reservoirs for corrosion inhibitors to be incorporated in the protective film. The common mechanism of the nanoreservoir activity is based on the slow release of inhibitor triggered by corrosion processes. Ion exchangers have also been investigated as 'smart' reservoirs for corrosion inhibitors. Chemically synthesized hydrocalmite behaves as an anion exchanger: adsorbing corrosive chloride ions and releasing corrosion-inhibiting nitrite anions. [7] Despite considerable efforts devoted to the development of new, complex anticorrosion systems, practically no single solution is able to fulfill the requirements of sufficient corrosion protection while avoiding chromates in the coating, especially in the ...

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Layer‐by‐Layer Assembled Nanocontainers for Self‐Healing Corrosion Protection

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“…Both surfaceapplied and admixed methods can be employed for the use of CLDH. In fact, Tatematsu and Sasaki [9] plastered the corrosioninhibiting paste admixed with hydrocalmitedone of LDHsdon the surfaces of w1-mm-thick reinforced steel bars. Thus CLDH can be also applied in same fashion with hydrocalmite.…”

Section: Application Of Cldh To the Cement And Concrete Industrymentioning

confidence: 99%

“…Hydrotalcite or LDH-like phases found in hydrated slag cement have been demonstrated to increase the binding capacity of chloride ions [7,8]. Tatematsu and Sasaki [9] admixed a hydrocalumite-like material to cement mixtures as a salt adsorbent, and Raki et al [10] demonstrated that LDH-like materials admixed in concrete can control the release rate of organic admixtures. Furthermore, several methods have been developed to utilize LDH-like phases in the construction industry [11e16], including hydrocalumite-or hydrotalcite-based admixtures to capture chloride and mortars containing hydrocalumite, which is used to repair RC structures.…”

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confidence: 99%

Chloride adsorption by calcined layered double hydroxides in hardened Portland cement paste

Yoon

Moon

Bae

et al. 2014

Materials Chemistry and Physics

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h i g h l i g h t sWe examine the adsorption equilibrium and kinetics of CLDH in the hydrated cement. CLDH capacity to bind chloride ions in the hydrated cement paste is determined. We model chloride adsorption by CLDH through the cement matrix. CLDH reforms the layered structure with ion adsorption in the cement matrix. s t r a c tThis study investigated the feasibility of using calcined layered double hydroxides (CLDHs) to prevent chloride-induced deterioration in reinforced concrete. CLDHs not only adsorbed chloride ions in aqueous solution with a memory effect but also had a much higher binding capacity than the original layered double hydroxides (LDHs) in the cement matrix. We investigated this adsorption in hardened cement paste in batch cultures to determine adsorption isotherms. The measured and theoretical binding capacities (153 mg g À1 and 257 mg g À1 , respectively) of the CLDHs were comparable to the theoretical capacity of Friedel's salt (2 mol mol À1 or 121 mg g À1 ), which belongs to the LDH family among cementitious phases. We simulated chloride adsorption by CLDHs through the cement matrix using the Fickian model and compared the simulation result to the X-ray fluorescence (XRF) chlorine map. Based on our results, it is proposed that the adsorption process is governed by the chloride transport through the cement matrix; this process differs from that in an aqueous solution. X-ray diffraction (XRD) analysis showed that the CLDH rebuilds the layered structure in a cementitious environment, thereby demonstrating the feasibility of applying CLDHs to the cement and concrete industries.Crown

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“…However, the corrosion of the reinforcement is the main cause of the structural concrete deterioration [1,2]. The exposure of these materials to a severe environment such as: temperature, deicing agents, humidity [3][4][5][6], aggressive ions mainly chlorides [7][8][9] and sulphates [10][11][12][13] makes them more vulnerable. Their durability depends also on the work design, material selection and their processing [14].…”

Section: Introductionmentioning

confidence: 99%

“…Compatibility of the repair material with the existing substrate is an important consideration if the repair is to withstand all the stresses induced by the influences, such as volume changes and chemical/electrochemical effects. Several types of concrete repair materials [8,11,20,21] have been introduced and used through years. These have ranged from polymer modifiers for Portland cement based products to pure polymers such as epoxy resins and polysters based systems.…”

Section: Introductionmentioning

confidence: 99%

Corrosion degradation and repair of a concrete bridge

Guettala

Abibsi

2006

Mater Struct

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Reinforced concrete corrosion has been widely reported in the literature over the last two to three decades even though certain cement concrete works remain in excellent state after more than one century of exposure to severe climatic conditions. This type of damage is responsible for the huge financial costs spent each year on the repair of deteriorated structures all over the world. This article describes the diagnosis carried out on the degradation of a reinforced concrete bridge put into service only 20 years back as well as the follow up repair. The stages of repair and reinforcement are discussed as well as its state after repair. The processes leading to damage and necessary repair strategies and procedures to avoid further damage under the given environmental conditions were obviously not understood by the designers of the repair works. It's also shown in this study the importance of maintenance and regular inspection of a given cement concrete work or the lack of it as is the case. Résumé La corrosion du béton armé aété largement reportée dans la littérature pour les deux dernières décennies malgré que certaines structures en béton armé demeurent dans unétat excellent après plus d'un siècle d'exposition aux conditions climatiquesA. Guettala · A. Abibsi Faculty of Engineering Biskra University -Algeria sévères. Ce type d'endommagement est responsable des coûts financiersénormes dépensées chaque année dans la réparation des structures détérioréesà travers le monde. Cet article décrit le diagnostique fait sur la dégradation d'un pont en béton armé mis en service il y'a seulement 20 années ainsi que le suivi après réparation. Les causes principales de la dégradation ainsi que les différentesétapes de réparation et le renforcement sont décrites et discutées. Des processus causant des endommagements et des stratégies nécessaires de réparation pouréviter encore plus de détérioration sous des conditions environnementales données n'étaient pas bien cernées par les concepteurs de ces travaux de réparation. Cetteétude a montré aussi l'importance de la maintenance et de l'inspection régulière ou plutôt leur absence comme c'est le cas.

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Repair materials system for chloride-induced corrosion of reinforcing bars

Cited by 51 publications

References 2 publications

Layer‐by‐Layer Assembled Nanocontainers for Self‐Healing Corrosion Protection

Layer‐by‐Layer Assembled Nanocontainers for Self‐Healing Corrosion Protection

Chloride adsorption by calcined layered double hydroxides in hardened Portland cement paste

Corrosion degradation and repair of a concrete bridge

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