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Alkali silica reaction - SlideShare

2018-12-11  ALKALI SILICA REACTION (ASR) A chemical reaction develops between the reactive silica contained in the aggregates and the alkalis (Na2O and K2O) within the cement paste known as Alkali-Silica Reaction. ASR also known as “Concrete Cancer” 8. INTRODUCTION In most concrete, aggregates are more or less chemically inert.

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PPT – Alkali-Silica Reaction: PowerPoint presentation ...

Alkali-Silica Reaction: Description: Less reactive aggregates often expensive or difficult to find ... exerting a force against surrounding concrete. Creation of alkali-silica gel ... – PowerPoint PPT presentation. Number of Views: 469. Avg rating:3.0/5.0. Slides: 27.

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The Alkali Silica Reaction In Concrete PowerPoint PPT ...

The Alkali Silica Reaction In Concrete PowerPoint PPT Presentations. All Time. Show: Recommended. Sort by: Alkali-Silica Reaction ... Alkali-Silica Reaction: - Possible ASR damage on concrete retaining wall - picture taken 1/2002 ... damage includes the presence of gel and staining. Creation of alkali-silica gel ... Possible ASR damage on concrete retaining wall - picture taken 1/2002 ...

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Lectures No. 09 10

Alkali silica reaction (ASR) Mechanism The reaction can be visualized as a two-step process: Alkali hydroxide + reactive silica gel → alkali-silica gel Alkali-silica gel + moisture → expansion Alkali silica reaction (ASR) The amount of gel formed in the concrete depends on Amount of and type of silica in aggregate. Alkali hydroxide concentration. Sufficient moisture. Alkali silica reaction ...

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ALKALI-SILICA REACTION by - Prezi

2014-09-22  Alkali-silica reaction may take from three to more than twenty-five years to develop in concrete structures, dependent on the nature of the aggregates used, the moisture content, temperature conditions and the concrete alkali content (Fournier et al, 2004).

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Alkali aggregate reaction - SlideShare

2018-01-01  Alkali-Aggregate Reaction Is the reaction between the active mineral constituents of some aggregates and the sodium and potassium alkali hydroxide in the concrete Harmful only when it produes significant expansion. 3. FORMS OF ALKALI AGGREGATE REACTIONS Alkali silica reactions alkali-carbonate reaction. 4.

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ALKALI-SILICA REACTION by - Prezi

2014-09-22  Alkali-silica reaction may take from three to more than twenty-five years to develop in concrete structures, dependent on the nature of the aggregates used, the moisture content, temperature conditions and the concrete alkali content (Fournier et al, 2004). Moisture is a crucial factor in the alkali-silica reaction

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The Alkali Silica Reaction In Concrete PowerPoint PPT ...

The Alkali Silica Reaction In Concrete PowerPoint PPT Presentations. All Time. Show: Recommended. Sort by: Alkali-Silica Reaction ... Alkali-Silica Reaction: - Possible ASR damage on concrete retaining wall - picture taken 1/2002 ... damage includes the presence of gel and staining. Creation of alkali-silica gel ... Possible ASR damage on concrete retaining wall - picture taken 1/2002 ...

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Research in Alkali Silica Reaction at Georgia Tech - [PPT ...

2016-02-13  Research in Alkali Silica Reaction at Georgia Tech Courtney Collins . Jason Ideker . Gayle Willis . Jessica Hurst What ASR research is going on at the Georgia Institute of

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Alkali Silica Reaction Ppt Prominer (Shanghai) Mining ...

Alkali Silica Reaction Ppt. Alkalies . ALKALI SILICA REACTION (ASR) POTENTIAL OF SAND AND GRAVELS FROM NW-HIMALAYAN RIVERS AND THEIR PERFORMANCE AS CONCRETE AGGREGATE AT THREE DAMS IN PAKISTAN Tamer Hassan a Dubai-based pharmacist explains that alkalies are soluble salts that are effective in removing dirt without excessive rubbing . Get Price . BRE Digest 330 Alkali

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Alkali-Silicate Reaction in Cement Silicon Dioxide ...

July 1992 Building Research Establishment, Digest 330 Pts 1,2,3 4, Alkali-silica reaction in concrete. 1997 Hobbs Dr D W, Alkali-silica reaction in concrete. T. Telford 1988 West G, Alkali-silica reaction in concrete roads and bridges. T.Telford 1996 Swamy R N, Alkali reaction in concrete. Blackie. 1992 This feature was compiled by David Doran [F]: Chairman of IStructE Task Groups; Member of ...

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The effects of alkali-silica reaction on the mechanical ...

by alkali-silica reaction (ASR). Three standard testing methods – ASTM C289, JASS 5N T-603 and ASTM C1260 – were used to identify the reactivity of ASR of the three aggregates selected. The test results show that all three aggregates are potentially deleterious. A new acceleration method based on JASS 5N T-603 and ASTM C1260 was proposed for concrete specimens. In the acceleration method ...

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Alkali-Aggregate Reaction

Alkali-silica reaction (ASR) is of more concern because aggregates containing reactive silica materials are more common. In ASR, aggregates containing certain forms of silica will react with alkali hydroxide in concrete to form a gel that swells as it adsorbs water from the surrounding cement paste or the environment. These gels can induce enough expansive pressure to damage concrete. Typical ...

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ALKALI AGGREGATE REACTIONS (AAR) IN CONCRETE

It is well documented that for alkali-silica reaction to occur, three conditions must be present: aggregate with reactive forms of silica, high-alkali (pH) pore solution, and sufficient moisture [2]. In the following a description of each of these factors concerning Finnish practise (reality) is given. Reactive aggregate – Finnish geology In Finland the bedrock is manly made of Precambrian ...

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Alkali Aggregate Reaction in Concrete - Types, Causes, and ...

Alkali-silica reaction generates enough expansive pressure to damage concrete. Cracking initiates in areas with a frequent supply of moisture, such as close to the waterline in piers, near the ground behind retaining walls, or in piers or columns subject to wicking action. It can be controlled using proper portions of supplementary cementitious materials like silica fume, fly ash, and ground ...

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Alkali-Aggregate Reaction (AAR) of Concrete Structures

alkali content of concrete, use of low alkali cement, include PFA, GGBS, etc. M2: Avoid the presence of a critical amount of reactive silica, e.g. identify non-reactive aggregate M3: reduce the access of moisture and maintain the concrete in a sufficiently dry state, e.g. use external cladding or tanking

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Alkali-Silica Reaction (ASR)

Alkali-Silica Reaction (ASR) Prohibitinguse of Class C Fly Ash. Sufficient Alkali Reactive Silica eactive grega Alkalies in Pore Solution eactive ggrega Si02 Alkalies Breakdown Aggregate and Release Reactive Silica ASR Gel Alkalies Silica Reacts with Alkalies and Absorbs Water to Produce Expansive ASR Gel Sufficient Moisture Si02 Cracking SiO Alk alies . Title: Microsoft PowerPoint - Final ASR ...

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Alkali-silica-reaction-durability-does-the-concrete ...

Displaying Powerpoint Presentation on alkali silica reaction durability does the concrete contain reactive aggregates yes available to view or download. Download alkali silica reaction durability does the concrete contain reactive aggregates yes PPT for free.

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poc alkali silica.pptx - Alkali-silica reaction(ASR This ...

poc alkali silica.pptx - Alkali-silica reaction(ASR This Topic Covers Following Contents ASR \u2026 Concrete Cancer Introduction to ASR What is. poc alkali silica.pptx - Alkali-silica reaction(ASR This... School U.E.T Taxila; Course Title CONSTRUCTI 101; Uploaded By Civil15ce94. Pages 29 This preview shows page 1 - 11 out of 29 pages. ...

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Investigating-the-effect-of-alkali-silica-reaction-in ...

Displaying Powerpoint Presentation on investigating the effect of alkali silica reaction in concrete made with available to view or download. Download investigating the effect of alkali silica reaction in concrete made with PPT for free.

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Alkali-Silicate Reaction in Cement Silicon Dioxide ...

July 1992 Building Research Establishment, Digest 330 Pts 1,2,3 4, Alkali-silica reaction in concrete. 1997 Hobbs Dr D W, Alkali-silica reaction in concrete. T. Telford 1988 West G, Alkali-silica reaction in concrete roads and bridges. T.Telford 1996 Swamy R N, Alkali reaction in concrete. Blackie. 1992 This feature was compiled by David Doran [F]: Chairman of IStructE Task Groups; Member of ...

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Alkali-SilicaReaction

Alkali-SilicaReaction Causes: Reaction between alkalis, usually fromcement and certain siliceousaggregates Reaction forms silica gel inside or roundthe periphery of theaggregate Silica gel absorbs water andswells Swelling eventually bursts the concreteand typical “map” cracksform. ٠٢/٠٦/١٤٣٩ ٢ Alkali Content: ASTM specifies the maximum alkalis content as 3 kg/m 3 or 0.6% of the ...

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ALKALI AGGREGATE REACTIONS (AAR) IN CONCRETE

It is well documented that for alkali-silica reaction to occur, three conditions must be present: aggregate with reactive forms of silica, high-alkali (pH) pore solution, and sufficient moisture [2]. In the following a description of each of these factors concerning Finnish practise (reality) is given. Reactive aggregate – Finnish geology In Finland the bedrock is manly made of Precambrian ...

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Alkali-silica reaction (ASR) - alkali sensitivity of ...

2011-01-01  In an alkali-silica reaction (ASR) alkali-reactive siliceous constituents of the aggregates react with the alkali and hydroxide ions (K⁺, Na⁺ and OH⁻) in the pore solution of the concrete to swellable alkali silica gel. Under adverse conditions, the volume of the alkali silicate gel may gradually expand to such an extent as to cause localised swelling pressure. This can damage the ...

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Concrete Alkali Silica Reaction Presentation - YouTube

2011-11-18  Dr Jason Eidiker of Oregon State University Presents His Research on Alkali Silica Reaction of Concrete

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State-of-the-Art Report on Alkali Silica Reactivity ...

2016-09-27  The alkali-silica reaction (ASR) related distress is a matter of great concern to the concrete industry and regarded as second most deterioration issue after corrosion. Reactive silica in the presence of alkali in the pore-solution inside the concrete creates a hydrophilic alkali-silica gel, often referred to as ASR gel. Formation of the ASR gel alone does not cause cracking; however when the ...

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