Study on strength and corrosion performance for steel embedded in metakaolin blended concrete/mortar

Parande, A.K.; Babu, B. Ramesh; Karthik, M. Aswin; Kumaar, K.K. Deepak; Palaniswamy, N.

doi:10.1016/j.conbuildmat.2006.10.003

Cited by 139 publications

(69 citation statements)

References 9 publications

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“…The advantages of adding MK (Al 2 Si 2 O 7 ) to concrete include enhanced compressive and bending strength, lower permeability, higher chemical resistance, improved workability, lesser efflorescence and longer durability (24,89,90). Adding approximately 10-15% MK raises reinforcing steel corrosion resistance (91,92). The presence of MK reduces chloride ion diffusion substantially in blended cement concretes (88,90,(93)(94)(95), while contradictory results have been reported for its performance in environments containing CO 2 (96,97).…”

Section: Adición De Materiales Mineralesmentioning

confidence: 99%

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: Adición De Materiales Mineralesmentioning

confidence: 99%

Durabilidad del hormigón armado expuesto a condiciones agresivas

Aguirre¹,

Gutiérrez²

2013

Mater. construcc.

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“…Estos autores llegaron a la conclusión de que puede ser necesario un 15% como mínimo de MK de alta reactividad para conseguir la resistencia a sulfatos a largo plazo, en función del contenido en C 3 A del cemento. Asimismo, la adición de hasta un 15% de metacaolín mejoró la resistencia a la corrosión de la armadura de acero (18). El rápido consumo del hidróxido cálcico (Ca(OH) 2 ) y el aumento del C-S-H y de la gehlenita hidratada (C 2 ASH 8 ) generados dan lugar al refinamiento de la estructura porosa, que se ha identificado como el principal mecanismo causante de la mejora de las propiedades del hormigón observadas al añadir MK (19,20).…”

Section: Introductionunclassified

“…These authors concluded that 15% or more high reactivity MK may be required for long-term sulfate resistance, depending on the C 3 A content of the cement. Furthermore, the addition of up to 15% metakaolin improved the corrosion resistance of reinforcing steel (18).The rapid consumption of calcium hydroxide (CH) and the increase in the amount of C-S-H and hydrated gehlenite (C 2 ASH 8 ) generated lead to refinement of the pore structure, identified as the main mechanism governing the improvement of concrete properties observed with the addition of MK (19 ,20 Four concrete mixes were prepared at a w/c ratio of 0.4 using four different binders (OPC, Type II cement, 75% OPC-25% MKH and 75% OPC-25% MKS). Concrete mix specifics are given in Table 2.…”

Section: Introductionmentioning

confidence: 99%

Propiedades y durabilidad del cemento con adición de metacaolín: mortero y hormigón

2010

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RESUMENEn este trabajo se estudia el efecto del metacaolín sobre las prestaciones del hormigón. Las probetas curadas a 360 y 90 días se sometieron a ensayos de resistencia a compresión y de tracción indirecta respectivamente. Se hizo un seguimiento de la resistencia a la compresión de los materiales ante el ataque de sales (soluciones de cloruro y de sulfato-cloruro) y, se midió la penetración de cloruros y la capacidad de los hormigones de inmovilizar estos iones. Los resultados se compararon con los obtenidos con hormigones elaborados con cemento pórtland ordinario (OPC) y, con cemento de calor de hidratación moderado (tipo II). El MK resultó influir muy positivamente en la resistencia del hormigón a 28 días debido a la mejora de la microestructura del cemento hidratado. La sustitución de cemento por metacaolín aumentó la resistencia del hormigón al ataque de cloruros. El hormigón con metacaolín demostró ser más duradero en entornos de sulfato-cloruro que los hormigones elaborados con OPC o con cemento de tipo II. Los perfiles de concentración de cloruros a distintas profundidades y la diferencia entre los contenidos de cloruro libre y total, mostraron claramente que el cemento con metacaolín reducía la penetración de cloruros en el hormigón y, aumentaba su capacidad para combinar con iones cloruro. La conclusión general fue que podía fabricarse material puzoláni-co utilizable, mediante la activación térmica del caolín local.Palabras clave: cemento con adiciones, metacaolín, ataque sulfatos-cloruros, penetración cloruros. SUMMARYThis article explores the effect of metakaolin, a pozzolan, on concrete performance. Compressive and splitting tensile strength were found for specimens cured for up to 360 and 90 days, respectively. Changes were recorded in the compressive strength of specimens exposed to salt (chloride and sulfatechloride solutions), and chloride penetration and binding capacity were measured. The findings were compared to the results for concrete prepared with ordinary Portland (OPC) and moderate heat of hydration (Type II) cement. MK was found to have a very positive effect on 28-day concrete strength, due to microstructure improvement of the hydrated cement. Replacing cement with metakaolin effectively raised concrete resistance to chloride attack. Concrete containing metakaolin proved to be substantially more durable in sulfate-chloride environment.Keywords: blended cement, metakaolin, sulfate-chloride attack, chloride penetration. Persona de contacto/Corresponding author: rafikaa65@yahoo.com INTRODUCCIÓNLos materiales puzolánicos como el humo de sílice (HS) y las cenizas volantes (CV) son componentes esenciales del hormigón de altas prestaciones. Cuando se emplean como aditivos minerales en el hormigón de altas prestaciones, pueden mejorar la resistencia y la durabilidad de dicho material. En los últimos años ha crecido el interés por el uso de metacaolín (MK) como adición mineral con este fin (1-3). Sabir y otros (4) y Siddique y Klaushave (5) han publicado recientemente monografías amplias sob...

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“…The dilution effect is a result of replacing a part of cement by the equivalent quantity of MK. In MK concrete, the filler effect, pozzolanic reaction of MK with calcium hydroxide and compounding effect (synergetic effect of mineral admixture) react opposite of the dilution effects (Parande et al 2008;Ding et al 1999). For this very reason, there was an optimum MK replacement for MK concrete.…”

Section: Mechanical Properties 321 Compressive Strengthmentioning

confidence: 99%

Effect of Metakaolin Content on the Properties of High Strength Concrete

Dinakar

Sahoo

Sriram

2013

Int J Concr Struct Mater

233

104

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This study presents the effect of incorporating metakaolin (MK) on the mechanical and durability properties of high strength concrete for a constant water/binder ratio of 0.3. MK mixtures with cement replacement of 5, 10 and 15 % were designed for target strength and slump of 90 MPa and 100 ± 25 mm. From the results, it was observed that 10 % replacement level was the optimum level in terms of compressive strength. Beyond 10 % replacement levels, the strength was decreased but remained higher than the control mixture. Compressive strength of 106 MPa was achieved at 10 % replacement. Splitting tensile strength and elastic modulus values have also followed the same trend. In durability tests MK concretes have exhibited high resistance compared to control and the resistance increases as the MK percentage increases. This investigation has shown that the local MK has the potential to produce high strength and high performance concretes.

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Study on strength and corrosion performance for steel embedded in metakaolin blended concrete/mortar

Cited by 139 publications

References 9 publications

Durabilidad del hormigón armado expuesto a condiciones agresivas

Durabilidad del hormigón armado expuesto a condiciones agresivas

Propiedades y durabilidad del cemento con adición de metacaolín: mortero y hormigón

Effect of Metakaolin Content on the Properties of High Strength Concrete

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