The effect of pozzolans and slag on the expansion of mortars cured at elevated temperature

Ramlochan, T; Thomas, M D; Hooton, R.D.

doi:10.1016/j.cemconres.2003.12.026

Cited by 104 publications

(42 citation statements)

References 18 publications

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“…It is known that the addition of SCMs can lower the pH of the pore solution 1-3 and this is considered to be related to the change in composition of the main binding phase-calcium silicate hydrate, C-S-H. 4,5 However, it has been observed that SCMs containing alumina seem to be more effective in reducing ASR than those containing only silica. [6][7][8] We have shown that the incorporation of alumina in C-S-H does not further reduce the alkalinity of the pore solution. 9 We have also shown that reactive aggregates stored in alkaline solutions containing alumina degrade less than those stored in equivalent solutions with no alumina.…”

Section: Introductionmentioning

confidence: 90%

The Effect of Aluminum in Solution on the Dissolution of Amorphous Silica and its Relation to Cementitious Systems

Chappex

Scrivener

2012

J. Am. Ceram. Soc.

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One of the most serious causes of degradation of concrete is the alkali–silica reaction. Amorphous silicates present in certain aggregates react with the alkaline pore solution of the concrete to form a gel, which absorbs water and swells, leading to the expansion of the concrete. It is known that the deleterious effects of ASR can be suppressed by the incorporation of supplementary cementitious materials in the concrete, but the mechanisms operating are not clear. In this article, we study a model system of amorphous silica plates in simulated pore solutions by X‐ray photoelectron spectroscopy (XPS), to demonstrate that aluminum in solution can directly suppress the dissolution of amorphous silica under the highly alkaline conditions found in concrete. XPS shows that aluminum species are incorporated into the framework of the silica structure. Scanning electron microscope (SEM) and atomic force microscope (AFM) images confirmed the reduction in dissolution of silica in solutions containing aluminum.

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Section: Introductionmentioning

confidence: 90%

The Effect of Aluminum in Solution on the Dissolution of Amorphous Silica and its Relation to Cementitious Systems

Chappex

Scrivener

2012

J. Am. Ceram. Soc.

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“…It is mainly found in structures that are in contact with a moist environment for several years [7] but also in the case of endogenous conditions [2]. The binder's composition is a major parameter of this phenomenon: DEF could be prevented when a part of the cement is replaced by pozzolanic or latent hydraulic additions, [9,11]. In case of using limestone filler, the results are more contrasted: Silva et al [12,13] have shown that DEF was not…”

mentioning

confidence: 99%

Influence of limestone filler and of the size of the aggregates on DEF

Shamaa

Lavaud²,

Divet³

et al. 2016

Cement and Concrete Composites

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“…Examples of this can include carbonation and alkali leaching (Ramlochan, Thomas, & Hooton, 2004;Spragg, 2013) and wet/dry cycling (Andrade, Bolzoni, & Fullea, 2011;Rajabipour & Weiss, 2008;Schiessel et al, 2000;Spragg et al, 2013b;Weiss, 1999). These interactions can create situations in which a layer develops at the surface that has electrical properties that differ from the interior material.…”

Section: Introductionmentioning

confidence: 99%

Surface and Uniaxial Electrical Measurements on Layered Cementitious Composites having Cylindrical and Prismatic Geometries

Spragg¹,

Jones²,

Villani³

et al. 2014

Proceedings of the 4th International Conference on the Durability of Concrete Structures

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Electrical measurements are becoming a common method to assess the transport properties of concrete. For a saturated homogenous system, the surface resistance and the uniaxial resistance measurements provide equivalent measures of resistivity once geometry is appropriately taken into account. However, cementitious systems are not always homogenous. This article compares bulk and surface resistance measurements in cementitious materials intentionally composed of layered materials (i.e., layers with different resistivities). For this study, layered systems were composed of paste and mortar layers, representing the heterogeneity that can exist in the surface layers of field applications as a result of differences in moisture content, segregation, ionic ingress, carbonation, finishing operations, or ionic leaching. The objective of this article is to illustrate that these electrical measures can differ in layered systems (with sharp layer boundaries) and to demonstrate the impact of the surface layer properties on the estimation for the underlying material properties, for both cylindrical and prismatic specimens. Accounting for the effects of a surface layer requires a separate correction in addition to the overall specimen geometry corrections.

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The effect of pozzolans and slag on the expansion of mortars cured at elevated temperature

Cited by 104 publications

References 18 publications

The Effect of Aluminum in Solution on the Dissolution of Amorphous Silica and its Relation to Cementitious Systems

The Effect of Aluminum in Solution on the Dissolution of Amorphous Silica and its Relation to Cementitious Systems

Influence of limestone filler and of the size of the aggregates on DEF

Surface and Uniaxial Electrical Measurements on Layered Cementitious Composites having Cylindrical and Prismatic Geometries

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