Alkali-aggregate reaction—identifying reactive silicates in complex aggregates by ESEM observation of dissolution features

Leemann, Andreas; Holzer, Lorenz

doi:10.1016/j.cemconcomp.2005.03.007

Cited by 30 publications

(24 citation statements)

References 11 publications

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“…EDX is available in all modes in the ESEM, and all elements down to boron can be detected, including the light elements such as carbon, nitrogen, and oxygen. 8 In the EDX analysis, an accelerating voltage of 20 kV with accounting time of 100 s was applied.…”

Section: Energy Dispersive X-ray Systemmentioning

confidence: 99%

Functionalization of ceramic fibers by metallic sputter coating

et al. 2009

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Ceramic fibers were functionalized by the sputter coating of copper in this study. The surface and interface structures of the functionalized ceramic fibers were investigated by atomic force microscopy (AFM) and environmental scanning electron microscopy (ESEM). The observations by AFM revealed the formation of nanoclusters on the fiber surface. The coated layer of the sputtered copper was also confirmed by the ESEM examination, equipped with an energy-dispersive X-ray analysis. It was also found that the electrical resistance of the ceramic fibers decreased with increased coating thickness. The interfacial bonding between fibrous substrate and sputter-coated copper was investigated and discussed by peel-off tests in this study. The mechanism of the interfacial adhesion between copper and fiber substrate was also discussed.

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Section: Energy Dispersive X-ray Systemmentioning

confidence: 99%

Functionalization of ceramic fibers by metallic sputter coating

et al. 2009

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“…Procedimiento experimental: consiste en atacar en superficie fragmentos de áridos con una solución saturada de Ca(OH) 2 , es decir portlandita (compuesto alcalino liberado en el fraguado del cemento), estudiándose la misma superficie antes y después del ataque mediante microscopía electrónica de barrido acoplada a análisis por energías dispersivas de rayos X (SEM) (Leemann & Holzer, 2005;Soriano, 1996).…”

Section: Método De Reactividad Superficial: Microscopía Electrónica Dunclassified

Evaluación de la reactividad árido-álcali en diversos áridos silicatados. Alternativas para minimizar esta reacción

Martı́n¹,

Gadea²,

Campos³

et al. 2010

Estud. geol.

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IntroducciónLa reacción álcali-silicato es un tipo de reacción árido-alcali que se produce cuando interaccionan áridos que contienen minerales silicatados potencialmente reactivos, con los álcalis del cemento (Stanton, 1948). Esta reactividad conlleva la formación de geles que muestran una gran avidez por el agua, lo que en presencia de humedad provoca su expansión (Mather, 1999;Menéndez & Soriano, 2007), y como consecuencia de ésta agrietamientos y, en definitiva, una disminución drástica de la durabilidad (Berube, 2002;Hobbs, 1988;Chrest et al., 1994).En este trabajo se han empleado dos métodos para evaluar la reactividad potencial de áridos, el

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“…It was observed especially in the basalt and the sandstone aggregates that the dissolution renders a "cardhouse" (Leeman and Holzer 2005) type microstructure which leads to a coarser and interconnected pore structure. The consequence would be a higher porosity thus low strength, easier ingress of alkali ions into the inner body and poor overall interlocking with the concrete matrix (i.e.…”

Section: Microstructural Featuresmentioning

confidence: 99%

“…(Leeman and Holzer 2005;Ben Haha et al 2007)). In agreement with those contributions, the results in this study have shown that the degradation of aggregate surface microstructure in course of ASR might be critical for the overall stability of the concrete structures.…”

Section: Microstructural Featuresmentioning

confidence: 99%

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Effect of Silica Dissolution on the Mechanical Characteristics of Alkali-Reactive Aggregates

Çopuroğlu

2010

ACT

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High pH nature of concrete microstructure can lead to chemical interaction between reactive silica in aggregate and alkali species in pore solution. As a result, alkali silica gel is rendered which can cause distress in hardened concrete. However, the consequence of silica dissolution is not only the gel formation and damage in cement paste, but also significant weakening of the reactive aggregate itself. In this study, three highly reactive, well-documented concrete aggregates were investigated. The aim was to characterize the micromechanical and -morphological alterations of the aggregates under aggressive alkaline solution by means of microscopy and nano-indentation techniques. It was found that silica dissolution alters micromorphology of the reactive aggregates and reduces elastic modulus and hardness values significantly.

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Alkali-aggregate reaction—identifying reactive silicates in complex aggregates by ESEM observation of dissolution features

Cited by 30 publications

References 11 publications

Functionalization of ceramic fibers by metallic sputter coating

Functionalization of ceramic fibers by metallic sputter coating

Evaluación de la reactividad árido-álcali en diversos áridos silicatados. Alternativas para minimizar esta reacción

Effect of Silica Dissolution on the Mechanical Characteristics of Alkali-Reactive Aggregates

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