The action of ammonium salts on concrete

Lea, F. M.

doi:10.1680/macr.1965.17.52.115

Cited by 52 publications

(18 citation statements)

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“…There are three methods to accelerate calcium leaching of cementitious materials: application of an electric field [17,33], using temperature [21] and using different chemical solutions to increase concentration gradients between the interstitial solution and the aggressive environment [13,32]. Ammonium nitrate (NH 4 NO 3 ) has been chosen by several authors as a representative aggressive solution for these accelerated experiments [3,10,19,25,26,30,34]. The principle of accelerated degradation with ammonium nitrate is the penetration of NH 4þ and NO 3À ions stemming from the dissolution of ammonium nitrate (Eq.…”

Section: Introductionmentioning

confidence: 99%

Influence of leaching on the local mechanical properties of an aggregate-cement paste composite

Jebli

Jamin

Garcia-Diaz

et al. 2016

Cement and Concrete Composites

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This paper presents an experimental study to characterize the mechanical behaviour, at the local scale, of sound and degraded concrete after leaching. An experimental protocol was developed to study the effects of the calcium leaching mechanism at the interfacial transition zone (ITZ) on the mechanical properties of the cement-aggregate interface and bulk paste of model material. The process of lixiviation with deionised water occurs very slowly. The experimental study in the laboratory was accelerated by replacing the water with an ammonium nitrate solution. To quantify the development and kinetics of degradation at the cemented bond, the concrete leaching fronts were characterized at different levels of degradation using phenolphthalein and local mechanical tests (compression and tensile) and performed on samples consisting of two aggregates bound by cement paste. Tests were performed on sound samples at different hydration times and on chemically degraded samples. The results show the effect of leaching on the mechanical properties of the samples and making it possible to correlate the progress of leaching to the evolution of these locally considered properties. The experimental results show that there is an ITZ effect on the alteration of the mechanical properties due to leaching.

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Section: Introductionmentioning

confidence: 99%

Influence of leaching on the local mechanical properties of an aggregate-cement paste composite

Jebli

Jamin

Garcia-Diaz

et al. 2016

Cement and Concrete Composites

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“…Furthermore, the interaction between phosphate ions, nitrogenbased pollutants and magnesium ions deriving both from concrete cementitious matrix and aggregate fraction, needs to be considered, both due to the extensive scientific literature regarding the detrimental action of ammonium salts on concrete [24][25][26] and the occurrence of ammonium phosphate phases like struvite under certain chemicalphysical conditions. Struvite ((NH 4 )MgPO 4 ·6(H 2 O)) is a hydrated phase consisting of magnesium, ammonium and phosphate in equal molar concentrations.…”

Section: Scientific Backgroundmentioning

confidence: 99%

Degradation processes of reinforced concretes by combined sulfate–phosphate attack

Secco

Lampronti

Schlegel

et al. 2015

Cement and Concrete Research

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“…The thickness of the removed parts is assessed using accelerated chemical degradation [23] and set to 10 mm. Samples are immersed in ammonium nitrate (6M).…”

Section: Samples Preparationmentioning

confidence: 99%

Impact of carbonation on the durability of cementitious materials: water transport properties characterization

Auroy

Poyet

Bescop

et al. 2013

EPJ Web of Conferences

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Abstract. Within the context of long-lived intermediate level radioactive waste geological disposal, reinforced concrete would be used. In service life conditions, the concrete structures would be subjected to drying and carbonation. Carbonation relates to the reaction between carbon dioxide (CO 2 ) and the main hydrates of the cement paste (portlandite and C-S-H). Beyond the fall of the pore solution pH, indicative of steel depassivation, carbonation induces mineralogical and microstructural changes (due to portlandite and C-S-H dissolution and calcium carbonate precipitation). This results in the modification of the transport properties, which can impact the structure durability. Because concrete durability depends on water transport, this study focuses on the influence of carbonation on water transport properties. In fact, the transport properties of sound materials are known but they still remain to be assessed for carbonated ones. An experimental program has been designed to investigate the transport properties in carbonated materials. Four hardened cement pastes, differing in mineralogy, are carbonated in an accelerated carbonation device (in controlled environmental conditions) at CO 2 partial pressure of about 3%. Once fully carbonated, all the data needed to describe water transport, using a simplified approach, will be evaluated.

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The action of ammonium salts on concrete

Cited by 52 publications

References 0 publications

Influence of leaching on the local mechanical properties of an aggregate-cement paste composite

Influence of leaching on the local mechanical properties of an aggregate-cement paste composite

Degradation processes of reinforced concretes by combined sulfate–phosphate attack

Impact of carbonation on the durability of cementitious materials: water transport properties characterization

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