The confused world of sulfate attack on concrete

Neville, Adam

doi:10.1016/j.cemconres.2004.04.004

Cited by 671 publications

(349 citation statements)

References 24 publications

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“…(2)- (4) (4) It is assumed that the expansions are caused only by the formation of secondary ettringite. The role of gypsum in the expansion mechanism is still far from clear [7], so in this study, the expansive nature of gypsum formation is not considered.…”

Section: -Chemical Reactions Consideredmentioning

confidence: 99%

Alternative methodology to consider damage and expansions in external sulfate attack modeling

Ikumi

Cavalaro

Segura

et al. 2014

Cement and Concrete Research

147

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A diffusion -reaction numerical model is proposed to simulate the response of concrete exposed to external sulfate attack. Diffusion properties are modified based on the strain reached and the ratio of porosity filled by ettringite. A direct and intuitive approach is proposed for the consideration of the diffusion in a cracked porous media based on the constitutive law of the material. A methodology to compute expansions based on a more realistic consideration of the concrete porosimetry is presented, by which it is possible to distinguish different strain contributions from different pore sizes. The described approach also allows the consideration of different capacities to accommodate expansive product for each pore size considered and the faster filling rate existent in small pores. Critical parameters of the numerical model developed are recognized and

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Section: -Chemical Reactions Consideredmentioning

confidence: 99%

Alternative methodology to consider damage and expansions in external sulfate attack modeling

Ikumi

Cavalaro

Segura

et al. 2014

Cement and Concrete Research

147

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“…An analysis by X-ray diffraction (XRD) was carried out before and after treatment. [46]. Ettringite is known to be an expansive material that can cause the disintegration of concrete [39].…”

Section: Treatment Of H 2 S Using Cellular Concrete In Abiotic Conditmentioning

confidence: 99%

Removal of hydrogen sulfide in air using cellular concrete waste: Biotic and abiotic filtrations

Jaber

Couvert

Amrane

et al. 2017

Chemical Engineering Journal

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Please cite this article as: M. Ben Jaber, A. Couvert, A. Amrane, P.L. Cloirec, E. Dumont, Removal of hydrogen sulfide in air using cellular concrete waste: biotic and abiotic filtrations, Chemical Engineering Journal (2017), doi: http://dx.doi.org/10. 1016/j.cej.2017.03.014 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. AbstractThe objective of this study was to investigate the removal of hydrogen sulfide (H 2 S) present in air using cellular concrete waste as the packing material. Air filtration was performed under biotic and abiotic conditions. Experiments were carried out in a laboratory-scale PVC column (internal diameter of 300 mm) filled with a volume of 70 L of cellular concrete (1 m height).The polluted air flow was generated at 4 m 3 h -1 corresponding to an Empty Bed Residence Time (EBRT) of 63 s. In dry conditions without biomass (abiotic conditions), cellular concrete can be an effective medium for the treatment of H 2 S in air. For an H 2 S concentration of 100 ppmv, the removal efficiency was around 70 % (Elimination Capacity (EC) of 5.6 g m -3 h -1 ). This finding can be explained by the physicochemical reactions that can take place between H 2 S and the cellular concrete components (mainly CaO, CaCO 3 and Fe 2 O 3 ).However, interactions between cellular concrete and H 2 S are not yet fully understood. Used as a packing material for H 2 S biofiltration (biotic conditions), cellular concrete waste efficiently 2 treated (Removal Efficiency = 100 %) high concentrations of H 2 S (up to 133 ppmv corresponding to an EC of up to 10.5 g m -3 h -1 ). Physicochemical and biological mechanisms explaining H 2 S removal seem to occur simultaneously in the biofilter. At an EBRT of 63 s, the maximal elimination capacity (EC max ) was 17.8 g m -3 h -1 . A packed bed of cellular concrete also presents a satisfactory mechanical behavior with low pressure drops.

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“…The most frequent cause is the alkali-aggregate reaction (AAR) (Stanton 1942;Hobbs 1988;Mehta and Monteiro 2006). Hence, the majority of reported dams with expansive reactions found in the literature are related with AAR (Shayan 1988, Regamey and Hammerschlag 1995, Ulm et al 2000, Saouma et al 2007, even though several cases were reported on internal sulfate attack (ISA) (Chinchón et al 1995, Ayora et al 1998, Oliveira et al 2013a, Oliveira et al 2013b, Oliveira et al 2014, Ikumi et al 2014, Chinchón-Payá et al 2015 and alkali-carbonate reaction (ACR) (Neville 2004, Blanco et al 2015.…”

Section: Introductionmentioning

confidence: 99%

Structural Diagnosis of a Concrete Dam with Cracking and High Nonrecoverable Displacements

Campos

López

Blanco

et al. 2016

J. Perform. Constr. Facil.

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Expansions in concrete dams may be caused by chemical or physical sources; however in certain occasions the evidences observed in the dam may not be attributed to a single cause. Mequinenza is an example of a concrete dam affected by expansions and high non-recoverable displacements that cannot be explained by the most frequent pathologies. This paper presents new hypotheses that could justify such behavior by assuming the superposition of a global phenomenon of water induced expansion in concrete in the entire dam and a localized effect consisting in the opening of cracks in the construction joints located in one of the blocks. This is validated by conducting numerical analyses through 2D finite element models that consider the nonlinear behavior of the construction joints and use zero-thickness interface elements to simulate the potential cracking planes in the dam. The results confirmed the diagnosis proposed and the capability of the model to reproduce the behavior of the dam, revealing the significant contribution of the opening of the cracks to the non-recoverable displacements in the dam.

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The confused world of sulfate attack on concrete

Cited by 671 publications

References 24 publications

Alternative methodology to consider damage and expansions in external sulfate attack modeling

Alternative methodology to consider damage and expansions in external sulfate attack modeling

Removal of hydrogen sulfide in air using cellular concrete waste: Biotic and abiotic filtrations

Structural Diagnosis of a Concrete Dam with Cracking and High Nonrecoverable Displacements

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