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Sulfate attack in concrete and mortar - WikiMili, The Best

Sulfates dissolved by ground moisture migrate into the concrete of the slab where they react with different mineral phases of the hardened cement paste. The attack arises from soils

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Sulfate attack in concrete and mortar - Wikipedia

Cement hydration and strength development mainly depend on two silicate phases: tricalcium silicate (C3S) (alite), and dicalcium silicate (C2S) (belite). Upon hydration, the main reaction products are calcium silicate hydrates (C-S-H) and calcium hydroxide Ca(OH)2, written as CH in the cement chemist notation. C-S-H is the phase playing the role of the glue in the cement hardened paste and responsible of its cohesion. Cement also contains two aluminate phases: C3A and C

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Sulfate Attack - an overview ScienceDirect Topics

Sulfate attack is the reaction between sulfate ions in the pore solution of concrete and constituents in the concrete that result in formation of new reaction products with a

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Sulfate attack in concrete and mortar - WikiMili, The Best

The attack arises from soils containing SO2−. 4 ions, such as MgSO 4 or NaSO 4 soluble and hygroscopic salts. The tricalcium aluminate (C 3 A) hydrates first interact with sulfate ions to form ettringite (AFt). Ettringite crystallizes into small acicular needles slowly growing in

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Sulfate Attack - an overview ScienceDirect Topics

Sulfate attack is another possible deterioration mechanism of concrete. It can have endogenous origin (developing without any contribution from the environment) or exogenous origins (such as sulfates contained in the soils or in liquids) (Germain, 2008; Neville, 2004).In both cases, the consequence is some volume expansion owing to the delayed formation of ettringite, which is

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Sulphate attack in Concrete, Its Effects, Causes and Prevention

The consequences of sulfate attack include not only disruptive expansion and cracking, but also loss of strength of concrete due to the loss of cohesion in the hydrated cement paste and of adhesion between it and the aggregate particles. Sulfates combines with the C-S-H, or concrete paste, and begins destroying the paste that holds the concrete ...

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Sulphate Attack on Concrete - Process and Control of ... - The

The quality of concrete; Control of Sulphate Attack on Concrete Following measures help to control sulphate attack”": 1. The quality of concrete, specifically a low permeability, is the best protection against sulphate attack. Adequate concrete thickness; High cement content; Low w/c ratio; Proper compaction and curing

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Sulfate Attack - What Why Avoid - Structural Guide

Sulfate attack is the reaction of the sulfate ions with the concrete and producing new formation within the concrete. As a result, the combination of chemical compositions is created and they tend to increase the internal volume of the concrete leading to internal stresses. Such expansions cause cracking, loss of strength of concrete, loss of ...

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What is sulfate attack? - Beton Consulting Engineers

Jun 07, 2021  What is sulfate attack? Concrete in certain environments is subject to sulfate attack. These include seawater, some industrial environments, sanitary sewers, and sulfate-bearing soils and groundwater. The latter commonly occur in the western United States and the prairie provinces of Canada, as well as in other parts of the world.

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Performance Evolution of Recycled Aggregate Concrete under the

The high porosity of recycled coarse aggregate, which results in recycled aggregate concrete (RAC) more vulnerable to freezendash;thaw (FT) damage and chemical attack, is a dominant factor that limits the industrialization of recycled aggregate concrete in civil engineering. This paper presents an experimental study on the combined effects of FT damage and sulfate

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Concrete Vs Mortar The Difference Which Is Best

Mortar uses slightly more water than concrete. You should be able to hold concrete in your hand and form it into a ball when it’s properly mixed. Mortar, on the other hand, is too wet to hold a form. Most mortar mixes have a compressive strength of around 1500 psi. Although some go as high as 3500 psi.

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Improving the sulfate attack resistance of concrete by using ...

This research work covers the performance of concrete specimens and reinforced concrete columns subjected to a 5% of magnesium sulfate attack for 700 days. This research was divided into two phases.

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Mechanical Properties and Damage Evolution of Concrete

Apr 30, 2021  When the fly ash content was 10%, concrete had the best resistance to sulfate attack . The reason for this is that the active substances in fly ash reacted with the Ca(OH) 2 in concrete, which reduced the content of Ca(OH) 2 in the concrete, reduced the production of gypsum and ettringite, and also alleviated the expansion of crystals.

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Wikizero - Sulfate attack in concrete and mortar

The attack arises from soils containing SO 2− 4 ions, such as MgSO 4 or NaSO 4 soluble and hygroscopic salts. The tricalcium aluminate (C 3 A) hydrates first interact with sulfate ions to form ettringite (AFt). Ettringite crystallizes into small acicular needles slowly growing in

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Chemical Sulfate Attack on Concrete - Civil Engineering Forum

Jan 26, 2017  Sulfate ions attack calcium hydroxide and the hydration products of C 3 A, forming gypsum and ettringite in expansive reactions. Depending on the cations involved with SO 4 such as Mg and Na, sulfate attack can be more or less aggressive. For instance, magnesium sulfate attacks concrete in a way similar to sodium sulfate but in addition, it forms brucite

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sulfate attack Topic - American Concrete Institute

Mar 01, 2022  rete. Sulfate attack can be classified as internal or external to the cementitious matrix. The underlying damage of sulfate attack can be chemical or physical deterioration. The course scope involves theoretical and experimental aspects of different forms of sulfate attack as well as case studies.

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sulfate attack - Deterioration of Concrete - LinkedIn

Jan 24, 2017  The effect of these changes is an overall loss of concrete strength. Other sources of sulfate which can cause sulfate attack include: Oxidation of

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Sulfate Attack of Concrete SpringerLink

Sep 20, 2012  The sulfate may be normal or as a consequence of disturbance, as by aeration with oxidation of sulfides in soil, in aggregate, etc. The damage to concrete structures resulting from external sulfate attack is related to the following factors: Transport of ions to the interior of the concrete through the pore system.

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Wikizero - Sulfate attack in concrete and mortar

The attack arises from soils containing SO 2− 4 ions, such as MgSO 4 or NaSO 4 soluble and hygroscopic salts. The tricalcium aluminate (C 3 A) hydrates first interact with sulfate ions to form ettringite (AFt). Ettringite crystallizes into small acicular needles slowly growing in

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sulfate attack - Deterioration of Concrete - LinkedIn

Jan 24, 2017  The effect of these changes is an overall loss of concrete strength. Other sources of sulfate which can cause sulfate attack include: Oxidation of

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Sulfate Attack of Concrete Request PDF - ResearchGate

Jan 01, 2013  Claudio Zega. The effect of recycled concrete aggregate (RCA) on concrete performance against external sulfate attack (ESA) is not yet fully known. In this paper, recycled aggregate concretes (RAC ...

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A Review Paper on the Effect of Sulphate Attack on Concrete Durability

Dune alluvial sand mortar with super-plasticizer exhibits the best behaviour under sulfate attack. The fall in the compressive and flexural strengths of mortars without Super-plasticizer is more than 50% for dune-alluvial sand mortars when immersed in sulfate solutions (MgS04 and NaS04) under high temperature of 50 °C for a period of 45 days ...

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Mechanical Properties and Damage Evolution of Concrete

Apr 30, 2021  When the fly ash content was 10%, concrete had the best resistance to sulfate attack . The reason for this is that the active substances in fly ash reacted with the Ca(OH) 2 in concrete, which reduced the content of Ca(OH) 2 in the concrete, reduced the production of gypsum and ettringite, and also alleviated the expansion of crystals.

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Sulfate Attack: Are We Missing the Mechanism Causing Most

–The best defense is low w/cm, well cured concrete • Atest (or better mix design and curing criteria) is needed to evaluate resistance of concrete to physical sulfate attack. • To evaluate resistance of concrete mixtures, it would seem logical to consider replacing strength maximum w/cm limits with a rapid fluid penetration resistance test.

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An Overview on Sulfate Attack - ctlgroupqatar

A concrete structure exposed to a rich sulfate environment or contained sulfate salts in its mix constituents (water, aggregates, or cement) can degrade rapidly and causes reduction of strength. Sulfate with the presence of water and cementitious paste will result in a process called Sulfate Attack. WHAT IS SULFATE ATTACK Sulfate attack on concrete is a chemical breakdown

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Review of Thaumasite Sulfate Attack on Cement Mortar and Concrete

Dec 12, 2012  Thaumasite sulfate attack (TSA) is one durability consideration. This paper reviews the features of TSA, factors affecting TSA, thaumasite formation mechanisms, and prevention measures. Finally, some needs for future studies are also suggested. TSA can completely destroy the cementitious binding ability of concrete by transforming it into a mush.

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Types of Sulphate Attack in Concrete- Influences and Sources

Fig. 1: Cracks in a Bridge due to Internal Sulphate Attack. 2. External Sulphate Attack. It is a more common type of sulphate attack which develops due to the ingression of sulphate present in soil or groundwater into concrete. Then the sulphate reacts with concrete constituents and subsequently the expansion product is formed.

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Sulfate resistance of portland-limestone cement concrete systems ...

Jul 30, 2020  The Type V mixture exhibited the best performance among all straight cement systems. However, it showed a clear increase in the rate of expansion after 1 year of testing, which may not indicate a high level of sulfate resistance. ... Sulfate resistance of mortar and concrete produced with portland-limestone cement and supplementary cementing ...

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AMMONIUM SULFATE ATTACK ON CEMENT MORTAR Challenges of Concrete ...

Jul 07, 2015  Challenges of Concrete Construction: Volume 6, Concrete for Extreme Conditions. AMMONIUM SULFATE ATTACK ON CEMENT MORTAR Authors: F Rendell. x. F Rendell. for articles by this author. University of East London, United Kingdom, and R Jauberthie. x. R Jauberthie. for articles by this author ...

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Identification of sulfate attack - Sulfate attack in concrete and mortar

9.2 Sulfate attack in concrete and mortar 9.2.5 Identification of sulfate attack. Severe damage to concrete and mortar can be readily identified from visual inspection. A range of different analytical techniques can be used to confirm that sulfate attack has occurred. ... Generally, the best technique for identifying sulfate attack is ...

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Performance Evolution of Recycled Aggregate Concrete under the

[2] Jiang L, Niu D, Yuan L, et al. Durability of concrete under sulfate attack exposed to freeze-thaw cycles[J]. Cold Regions Science and Technology, 2015, 112: 112–117. Comment 9: Properties of the SP need to be supplied. Response: Thank you for your suggestion. Properties of the SP have been supplied in the revised manuscript (Table 2). Table 2

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