Sulfate resistance and carbonation of plain and blended cements

Sideris, Kosmas K.; Savva, A.; Papayianni, J.

doi:10.1016/j.cemconcomp.2005.09.001

Cited by 97 publications

(40 citation statements)

References 8 publications

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“…Una baja relación agua/cemento reduce la permeabilidad y dificulta el ingreso de los iones sulfato; el uso de adiciones puzolánicas (cenizas volantes, escorias, metacaolín, entre otras) aumenta la resistencia a sulfatos; al respecto se han realizado diversas investigaciones (15)(16)(17)(18)(19)(20).…”

Section: Ataque Por Sulfatosunclassified

“…En el sistema se generan reacciones químicas: en el cátodo se evidencia la producción de iones hidroxilo [14], por lo cual el valor del pH alrededor del acero de refuerzo se incrementa; igualmente se genera hidrógeno, y si el potencial aplicado es muy negativo podría producirse fragilización por hidrógeno (142,156). En el ánodo se da lugar a la transformación de hidroxilos en oxígeno y agua acorde a [15]. [15]…”

Section: Realcalinización Electroquímica (Re)unclassified

“…A low water/cement ratio lessens permeability and hinders sulfate ion ingress; the use of pozzolanic additions (such as fly ash, slag or metakaolin) raises sulfate resistance, as observed in a number of studies (15)(16)(17)(18)(19)(20).…”

Section: Ataque Por Sulfatosmentioning

confidence: 99%

“…As hydrogen is likewise generated, and if the potential applied is very negative, hydrogen embrittlement may also appear (142,156). In the anode, hydroxyls are converted into oxygen and water as in [15].…”

Section: Electrochemical Realkalinisation (Er)mentioning

confidence: 99%

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Durabilidad del hormigón armado expuesto a condiciones agresivas

Aguirre¹,

Gutiérrez²

2013

Mater. construcc.

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Reinforced concrete is the most widely used construction material in the world. The combination of high compressive strength, afforded by concrete and, and the excellent mechanical properties that characterise steel make it an ideal composite for all manner of structures. One of the main weaknesses of this material, however, is that when the concrete is exposed to aggressive environments, in particular high concentrations of chloride ions or carbon dioxide, reinforcing steel corrodes, shortening service life. This article reviews the state of the art on concrete durability, along with the conditions that affect its useful life by inducing reinforcing steel corrosion. It also discusses the prevention and control methods, in particular electrochemical prevention and rehabilitation techniques, that have been developed to mitigate the problem.Keywords: reinforced concrete; steel corrosion; mineral additions; electrochemical rehabilitation. RESUMENEl hormigón armado se ha convertido en el material más utilizado a nivel mundial en el sector de la construcción. La combinación de las altas prestaciones a resistencia a la compresión que ofrece el hormigón y las excelentes propiedades mecánicas del acero lo hacen el material compuesto ideal para aplicaciones estructurales. Sin embargo, uno de los mayores problemas que afecta la vida útil del hormigón es la corrosión del acero de refuerzo, la cual se presenta cuando el hormigón se encuentra expuesto a ambientes agresivos, en especial frente a la exposición a iones cloruros y/o dióxido de carbono. Este trabajo revisa el estado del conocimiento con respecto a la durabilidad del hormigón enfatizando en los fenóme-nos que afectan su durabilidad y generan la corrosión del acero de refuerzo, adicionalmente se incluyen los métodos de prevención y control que se han desarrollado para mitigar el problema, en particular los relacionados con las técnicas electroquímicas de prevención y rehabilitación. INTRODUCTIONVersatility and low cost have made concrete one of the world's most popular construction materials (1, 2). This ceramic material is characterised by high compressive strength, although it is prone to cracking under other types of mechanical stress such as bending and tensile forces, torque and shear. That weakness led to the advent of reinforced concrete, a combination of concrete and structural steel widely used to build bridges, buildings in general and skyscrapers in particular, tunnels and a host of other structures. One of the most important features of concrete, in addition to its mechanical properties, is its durability, which is associated with the inservice life of structures exposed to certain conditions or environments (3, 4). More specifically, reinforcing steel corrosion has been identified as the main weakness of reinforced concrete (5). This paper discusses the main types of concrete deterioration, including the processes that contribute to steel corrosion, and the respective prevention and control methods, such as the use of inhibitors and coatings, ...

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Section: Ataque Por Sulfatosunclassified

Section: Realcalinización Electroquímica (Re)unclassified

Section: Ataque Por Sulfatosmentioning

confidence: 99%

Section: Electrochemical Realkalinisation (Er)mentioning

confidence: 99%

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Durabilidad del hormigón armado expuesto a condiciones agresivas

Aguirre¹,

Gutiérrez²

2013

Mater. construcc.

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“…This reaction results into secondary C-S-H and forms more dense mortar and pores of similar diameter. Consumption of excess calcium hydroxide due to pozzolanic reaction is reported by Sideris et al [3] to render it unavailable for the formation of ettringite and gypsum compounds. The formation of ettringite and gypsum compounds in hardened cementitious systems is responsible for expansion.…”

Section: B Effect Of Pwc Additive On External Sulphate Attack Of Mormentioning

confidence: 99%

Effect of a Modified Pozzolan on the Sulphate Attack Resistant of Mortar

Ikotun¹,

Ikotun²

2014

IJET

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Abstract-Durability of mortar/concrete is a vital property that affects its serviceability. One of the factors that affect concrete durability is sulphate attack, which can result to expansion, cracking, deterioration, and deformation of concrete structures. The effect of a modified pozzolan (PWC) on the sulphate attack resistant of mortar was investigated in this study. The additive, a blend of selected alkaloids and zeolite, is commercially available and effectively used in soil stabilization for road construction. The additive pozzolanic behaviour had been observed in previous study in terms of strength and permeability. However, the present study focuses on its resistant to sulphate attack as a pozzolan. PWC additive was used in the proportions of 0 %, 0.4 %, 0.6 % and 2.5 % by weight of cement. Samples were subjected to both internal and external sulphate attack tests, according to ASTM C1038 and ASTM C1012 respectively, after being cured for 14, 28, 60, 90, 120, 180, and 295 days. The results showed that PWC additive when used at low dosages of 0.4 % and 0.6 % PWC causes reduction in expansion due to external sulphate attack. At higher dosages of PWC additive, greater external expansion occurs when compared to control samples.

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