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Effects of curing condition and particle size of aggregate ...

Effects of curing condition and particle size of aggregate ...

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Apr 24, 2019 · 1. Introduction. Alkali–carbonate reaction (ACR) is a kind of alkali–aggregate reaction, which means the alkali in the concrete reacts with dolomite crystals, leading to maplike cracks in the concrete and deterioration of concrete.

"Mitigation and Evaluation of AlkaliSilica Reaction (ASR ...

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Sep 19, 2017 · An evaluation of alkalisilica reaction (ASR) and freezing and thawing (F/T) in concrete transportation structures is presented along with mitigation methods for slowing the rate of deterioration in concrete. A combination of field and laboratory testing confirms ASR deterioration is exacerbated by exposure to F/T. Laboratory testing indies an aggregate previously deemed inert .

Reaction of quartz glass in lithiumcontaining alkaline ...

Reaction of quartz glass in lithiumcontaining alkaline ...

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Sep 12, 2018 · 1. Introduction. The use of lithium compounds to mitigate alkali–silica reaction (ASR) has been extensively investigated ever since the beneficial effects of lithium ions (Li +) on ASRcaused expansion were reported in 1951 [].However, the exact role of Li + in controlling ASR is still unclear [2–5].Several mechanisms have been proposed, including (i) enhancement in chemical stability of ...

Experimental research on the mechanical properties of ...

Experimental research on the mechanical properties of ...

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Jun 07, 2018 · Alkali excitant usually refers to caustic alkali and silie containing the alkaline element, phosphate, aluminate, sulfate, carbonate, and so on. Its hydration reaction on the geopolymer provided an alkaline, and displayed a alytic action. It also provided free silie ions which caused a polymerization reaction.

Factors affecting durability of concrete • Aggregate ...

Factors affecting durability of concrete • Aggregate ...

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Jan 27, 2010 · Resistance to AlkaliSilica Reaction (ASR): ASR is an expansive reaction between reactive forms of silica in aggregates and potassium and sodium alkalis, mostly from cement, but also from aggregates, pozzolans, admixtures, and mixing water. The reactivity is potentially harmful only when it produces significant expansion.

Expansion behaviour of glass aggregates in different ...

Expansion behaviour of glass aggregates in different ...

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Jul 23, 2008 · Crushed waste glass was first used as a concrete aggregate in 1974 [] with disappointing results due to expansive alkalisilica reaction (ASR) between the amorphous silica in the glass and the alkaline cement the past decade however, a number of major research projects in the USA and the UK [2–14] have been conducted in this studies agree that all glass aggregates .

AlkaliSilica Reaction In Concrete

AlkaliSilica Reaction In Concrete

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By KAUSHAL KISHORE Materials Engineer, Roorkee The problem of Alkalisilica reaction was believed to be nonexistent in India till 1983, when its occurrence was diagnosed in two concrete dams. This paper describes this problem with respect to Indian aggregates and cement. A rapid method of test for alkaliaggregate reaction is investigated and described in the [.]

(PDF) Geopolymer concrete

(PDF) Geopolymer concrete

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Download fulltext PDF ... alkali–aggregate ... geopolymercementconcrete has micro compact structure as the result of the filling effect of inactivated fly ash and alkali activated reaction. ...

ASTM C142 PDF

ASTM C142 PDF

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Apr 23, 2020 · Aggregates for Concrete – ppt video online download. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may attend. Cracking of concrete from alkalisilica reactivity. If the document is revised or amended, you will be notified by email.

The Pessimum Ratio and Aggregate Size Effects on Alkali ...

The Pessimum Ratio and Aggregate Size Effects on Alkali ...

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Abstract Alkali aggregate reaction is a chemical reaction that occurs between the reactive component of the aggregate and alkali hydroxide from the cement used in concrete or external source. In this study, the accelerated mortar bar tests were performed and their results were compared with each other in order to investigate the ratio of reactive aggregate which causes maximum expansion in ...

Determination of Potassium, Sodium, and Total Alkalies in ...

Determination of Potassium, Sodium, and Total Alkalies in ...

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A simple flow injection with flame photometric detection has been developed for determination of sodium, potassium, and total alkalies in portland cement, fly ash, admixtures, and water of concrete. A liquid sample or a digest of solid sample was injected into a water carrier stream which flowed to a flame photometer. A change in emission intensity at a selected wavelength was recorded as a peak.

56 Logam Alkali Lengkap PPTs View free download ...

56 Logam Alkali Lengkap PPTs View free download ...

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Global ChlorAlkali Plants Market Research Report 2018 2018 Global ChlorAlkali Plants Industry Report is a professional and indepth research report on the world's major regional market conditions of the ChlorAlkali Plants industry, focusing on the main regions (North America, Europe and Asia) and the main countries (United States, Germany, Japan and China).

(PPT) Nobel Prizes in Physics 1901 – ...

(PPT) Nobel Prizes in Physics 1901 – ...

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Download Free PPT. Download Free PDF. Nobel Prizes in Physics 1901 – Amarendra Chaudhuri. Download PDF. Download Full PDF Package. This paper. A short summary of this paper. 37 Full PDFs related to this paper. ... Nobel Prizes in Physics 1901 –

Determination of Potassium, Sodium, and Total Alkalies in ...

Determination of Potassium, Sodium, and Total Alkalies in ...

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A simple flow injection with flame photometric detection has been developed for determination of sodium, potassium, and total alkalies in portland cement, fly ash, admixtures, and water of concrete. A liquid sample or a digest of solid sample was injected into a water carrier stream which flowed to a flame photometer. A change in emission intensity at a selected wavelength was recorded as a peak.

Alkali–carbonate reactions and 'dedolomitization' in ...

Alkali–carbonate reactions and 'dedolomitization' in ...

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Adverse reactions between specific aggregate particles and the pore fluids in cement pastes have been widely reported, and have been regarded as responsible for the failure of the structures into which the resulting concrete had been emplaced. The reactivity of aggregates containing various forms of silica has been well understood but similar reactions, apparently taking place between ...

Electrochemical induction of alkalisilica reaction in ...

Electrochemical induction of alkalisilica reaction in ...

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For concrete specimens containing calcined flint aggregate, it was shown that deleterious local expansion of the material was generated owing to alkalisilica reaction induced in the vicinity of embedded steel when the latter was subjected to potentiostatic polarization for a period of several months at −850 mV (SCE scale).

STUDY ON CONCRETE AGGREGATE ALKALI REACTIVITY IN INTAKE ...

STUDY ON CONCRETE AGGREGATE ALKALI REACTIVITY IN INTAKE ...

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The preliminary accelerated mortarbar test showed that the aggregate has potential alkali activity hazards in intake complex of CCS hydropower station in Ecuador. Used volcanic ash and volcanic ash+silica fume as admixture to inhibit the alkali activity of aggregate. The results show that adding volcanic ash or volcanic ash+silica fume has a significant inhibition effect on the alkali ...

PPT – Structural Problems and Its Solutions PowerPoint ...

PPT – Structural Problems and Its Solutions PowerPoint ...

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The Onset of ASR/Aar (AlkaliSilica Reaction)/(AlkaliAggregate Reactions) Use of deep penetrating waterproof sealers. These waterproof sealers greatly reduce water and vapour drive ; It also extracts fluid contaminants our of the concrete. 7 Spalling Concrete caused due to Freeze Thaw Cycling. Proper Use of Surface and penetration sealers

250+ TOP MCQs on Admixtures and Answers

250+ TOP MCQs on Admixtures and Answers

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d) To control the alkaliaggregate expansion or alkali silica reaction Answer: c Clarifiion: To decrease the capillary flow of water through concrete and to increase its impermeability to liquids is incorrect in the above statement.

Types of Chemical Attacks on Concrete Structures

Types of Chemical Attacks on Concrete Structures

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AlkaliAggregate reaction on concrete Alkali aggregate reaction is the chemical reaction between alkali in cement and silica content of aggregates. Hence it can also be called as Alkali Silica reaction. When this reaction takes place, a gel like substance is formed which absorbs water and volume of concrete will increase.

7 Lab Test on Aggregate Should Satisfy for Use in Concrete

7 Lab Test on Aggregate Should Satisfy for Use in Concrete

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Dec 19, 2019 · In other words, alkaliaggregate reaction is the expansive reaction that takes place between alkali and elements within an aggregate which can result in pattern cracking, surface pop outs and break off into fragments if it is severe enough. There are two types of alkali aggregate reaction occurring, 01. AlkaliSilica Reaction (ASR) 02.

PPT – Recycling and Utilization of Mine Tailings as ...

PPT – Recycling and Utilization of Mine Tailings as ...

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PPT – Recycling and Utilization of Mine Tailings as Construction Material through Geopolymerization PowerPoint presentation | free to download id: 5a268fMzA0O. The Adobe Flash plugin is needed to view this content. Get the plugin now

15 Types of Admixtures Used in Concrete

15 Types of Admixtures Used in Concrete

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9. Alkali Aggregate Expansion Preventing Admixtures Alkali aggregate expansion in concrete is happened by the reaction of alkali of cement with the silica present in the aggregates. It forms a gel like substance and cause volumetric expansion of concrete which may lead to cracking and disintegration.

AlkaliStabilized PtOHx Species Catalyze LowTemperature ...

AlkaliStabilized PtOHx Species Catalyze LowTemperature ...

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Sep 24, 2010 · Abstract. We report that alkali ions (sodium or potassium) added in small amounts activate platinum adsorbed on alumina or silica for the lowtemperature watergas shift (WGS) reaction (H 2 O + CO → H 2 + CO 2) used for producing H alkali ion–associated surface OH groups are activated by CO at low temperatures (~100°C) in the presence of atomically dispersed platinum.