Diagnosis of concrete structures distress due to alkali-aggregate reaction

Owsiak, Z.; Zapała-Sławeta, Justyna; Czapik, Przemysław

doi:10.1515/bpasts-2015-0003

Cited by 22 publications

(22 citation statements)

References 4 publications

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“…In 2015, a special issue of the Bulletin of the Polish Academy of Sciences: Technical Sciences dedicated to diagnosis and durability of buildings was published [13]. Studies published in that issue: K. Flaga [14]; Z. Owsiak et al [15,16]; Z. Rusin et al [17]; L. Czarnecki, P. Woyciechowski [18]; B. Goszczyńska et al [19]; K. Wilde et al [20]; A. Garbacz [21]; Z. Hoła [22]; M. Iwański [23]; A. Szydło [24]; A. Piekarczuk et al [25]; M. Kolbrecki [26]; D. Kowalski et al [27] are considerable evidence of achievements and research ambitions in this area.…”

Section: Czarnecki and D Van Gemert Scientific Basis And Rules Ofmentioning

confidence: 99%

Scientific basis and rules of thumb in civil engineering: conflict or harmony?

Czarnecki

Gemert

2016

Bulletin of the Polish Academy of Sciences Technical Sciences

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Abstract. Science and engineering intermingle in the area of construction. Engineering works, often of great dimensions and design life cycle of many decades, have to be designed on a scientific basis since the safety of hundreds of users depends on their design. The task of scientific institutions is to define the construction performance within categories that correspond to the contemporary level of knowledge and technology. A construction appraiser who speaks out in a way that ensures unquestionable competence about the performance of elements and buildings (existing and under construction), should be convinced of the scientific basis of his opinions. A comparison of construction sections vs. basic requirements presents an archetype of the science of construction. A matrix of the science of construction reveals its multi-faceted nature; if related to time -the issue of durability has to be considered, and if related to the scale -the complexity. Defining the construction performance in terms of technical features is a constant search for a relationship between the material model and the usability model of a building. The construction industry uses a lot of "rules of thumb", more than any other sector of technology. In the era of computer-aided design, CAD, and building information modelling (BIM), those rules of thumb remain invaluable verification tools.Key words: building performance, appraiser, matrix of the science of construction, rules of thumb, durability, complexity, diversified development. Scientific basis and rules of thumb in civil engineering Defining building performanceThe primary task of universities and research institutes in the scientific discipline of construction is to continuously define building performance in a manner consistent with the current level of knowledge and technology. This means permanently seeking true solutions [2] -the relationship between the two corresponding models [3]: the material model (material model is used here to represent materials, analyses and geometries) and the usability model, which combines properties and requirements (Fig. 1).

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Section: Czarnecki and D Van Gemert Scientific Basis And Rules Ofmentioning

confidence: 99%

Scientific basis and rules of thumb in civil engineering: conflict or harmony?

Czarnecki

Gemert

2016

Bulletin of the Polish Academy of Sciences Technical Sciences

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“…Two currently recognized types of AAR are reactions between alkalis and aggregates containing reactive silica (ASR) and reactions between alkalis and carbonate aggregates (ACR). Due to more frequent presence of reactive forms of silica such as opal, tridymite, chalcedony, and strained quartz, in aggregates used in concrete, ASR is usually the main process responsible for the deterioration of concrete structures [1]. The reaction between aggregates and sodium and potassium hydroxides, which originate mainly from the cement, produces a sodium potassium-calcium silicate gels, which absorbs water and swells.…”

Section: Introductionmentioning

confidence: 99%

“…In some cases the destruction of concrete was incorrectly attributed to other deterioration processes, excluding the reaction with alkalis [4]. In Poland, no cases of destructive alkaline reaction have been reported so far, however, the presence of reactive aggregates has been found in the regions of north-eastern and south-west Poland [5][6][7]. It is further necessary to take into account that concretes in road structures are highly exposed to AAR, which results from the limited possibility of protecting them from moisture.…”

Section: Introductionmentioning

confidence: 99%

“…Cement with mineral additives may also be used, where it is possible to increase the permissible content of alkali in cement [9]. The methods of preventing the effects of ASR include the use of lithium compounds, mainly lithium nitrate and lithium hydroxide [10][11][12]. The risk of alkali attack is only possible here at the mixing stage of concrete production.…”

Section: Introductionmentioning

confidence: 99%

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The use of lithium compounds for inhibiting alkali-aggregate reaction effects in pavement structures

Zapała-Sławeta

Owsiak

2018

IOP Conf. Ser.: Mater. Sci. Eng.

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Abstract. Internal corrosion of concrete caused by the reaction of reactive aggregate with sodium and potassium hydroxides from cement is a threat to the durability of concrete pavements. Traditional methods for reducing the negative effects of the reaction include the use of unreactive aggregates, low alkali cements, mineral additives or chemical admixtures, incorporated during mixing. Lowering the relative humidity of the concrete below 80% is another measure for limiting the destructive reaction. The incorporation of lithium compounds, in particular lithium nitrate and lithium hydroxide, to the concrete mix is a method of limiting alkali-silica reaction effects. The challenge is to reduce the negative effects of aggregate reactivity in members in which the reaction has occurred because the aggregate happened to be reactive. The paper presents ways of limiting the deterioration of ASR-affected concrete in road pavements and other forms of transportation infrastructure, mainly through the use of lithium compounds, i.e. lithium nitrate. Impregnation methods that allow the penetration of lithium ions into the concrete structure were characterized, as was the effectiveness of the solutions applied.

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“…Differences in the mineral composition of constituent aggregates make it difficult to find effective ways of reducing the reaction effects. Another difficulty stems from different reaction rates of aggregate rocks [1]. The effects of the reaction between aggregates and Na + and K + ions can be greatly reduced by pozzolanic and hydraulic additions or some chemical admixtures, as actively investigated and reported in Polish specialist literature.…”

Section: Introductionmentioning

confidence: 99%

Effect of lithium nitrate on the reaction between opal aggregate and sodium and potassium hydroxides in concrete over a long period of time

Zapała-Sławeta

Owsiak

2017

Bulletin of the Polish Academy of Sciences Technical Sciences

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Abstract. Alkali-silica reaction (ASR) is a reaction between amorphous or poorly crystallized siliceous phase, present in aggregates, and sodium and potassium hydroxides in the pore solution of concrete. Chemical admixtures such as lithium compounds are known to have high potential of inhibiting ASR. The aim of this study was to determine the effect of lithium nitrate on ASR in mortars containing high reactive opal aggregate over a long period of time. Mortar bar expansion tests were performed and microstructures of mortar bars were observed by scanning electron microscopy coupled with an energy dispersive X-ray microanalyser. Results from this study showed that effectiveness of lithium nitrate in mitigating ASR was limited over a long period of time. A larger amount of ASR gel which was formed in the presence of lithium nitrate indicated that the deterioration processes intensify within longer periods of time, which so far has not been observed in literature. Microscopic observation confirmed the presence of alkali-silica gel and delayed ettringite in mortars with lithium nitrate.Key words: alkali-silica reaction, lithium nitrate, ettringite formation, expansion, SEM/EDS. Effect of lithium nitrate on the reaction between opal aggregateand sodium and potassium hydroxides in concrete over a long period of time J. ZAPAŁA-SŁAWETA * and Z. OWSIAK Kielce University of Technology eses have been put forward to explain the role of lithium ions in the reaction. These include, but are not limited to, a hypothesis of reduced silica reactivity caused by the formation of a layer of lithium silicate crystallites or lithium ion-rich amorphous products on the silica surface. This layer on the surface of the aggregate prevents the reaction of silica with sodium and potassium hydroxides [12,13]. Recent years have brought more reports on the modified composition and properties of sodium-potassium-calcium silicate gels with lithium ions. Sodium and potassium ions in gels are exchanged for lithium ions, which makes them less swellable [14,15]. Gels with lithium ions are more compact, which limits the diffusion of hydroxyl, sodium and potassium ions into reactive grains [16]. Studies of the alkali-aggregate reaction have often indicated the presence of delayed ettringite [17,18]. The coexistence of aggregate reaction products with ettringite has been widely observed, especially in concrete railway sleepers in Finland, Sweden, Australia, Germany, South Africa, United States and China [19][20][21][22][23]. According to the current state of knowledge, the delayed ettringite crystallizes in the microcracks generated by the aggregate reaction with sodium and potassium hydroxides, but is not the primary source of the cracks [24,25]. Ettringite is not produced in strongly alkaline environments. However, when the concentration of sodium and potassium hydroxides decreases as a result of reacting with reactive aggregates, the conditions for its crystallization become favourable [26,27].Data on the simultaneous effects of lithium ions on alkali...

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Diagnosis of concrete structures distress due to alkali-aggregate reaction

Cited by 22 publications

References 4 publications

Scientific basis and rules of thumb in civil engineering: conflict or harmony?

Scientific basis and rules of thumb in civil engineering: conflict or harmony?

The use of lithium compounds for inhibiting alkali-aggregate reaction effects in pavement structures

Effect of lithium nitrate on the reaction between opal aggregate and sodium and potassium hydroxides in concrete over a long period of time

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