concrete - Boral

Bleeding is the movement of water to the surface of freshly placed concrete. Excessive ... Admixtures are used in concrete (often in combination) to impart specific qualities to the fresh ... Superplasticisers or high range water reducers can greatly increase slump with a relatively small dose. ... place it rather than pour it. 12.

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Utah State University - OSF

Cure freshly poured concrete where superior ... not exist when mixed with other admixtures in concrete. Breathing ... mid-range and high-range water reducer.

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Chemical Admixtures for Concrete

These admixtures can be used with mid-range or high-range water reducers to provide desired levels of workability retention in moderate to high slump concrete mixtures. Their main benefit is reducing the need for slump adjustments prior to concrete placement, thus helping to maintain consistency in concrete performance throughout a project.

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MASSIVE CONCRETE PLACEMENTS

2011年12月20日 — Admixture for Concrete (Retarder, High Range Water Reducer, etc) ... Fresh concrete temperature shall be in relation to. – Section dimension.

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A Closer Look: Water-Reducing Admixtures - NPCA

Mid-range water reducers. Mid-range water reducers typically reduce water content by 10 to 15% for concrete with a slump range from 5-to-8 inches. They must usually comply with the requirements of ASTM C494 Type F (water reducing, high range) and Type G (water reducing, high-range and retarding) admixtures. Mid-range water reducers can help ...

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Premiere Concrete Admixtures High Range Water Reducers ...

UltraFlo® water reducers are normal setting multi-range water-reducing admixtures for concrete. They are designed to facilitate the placing and finishing of concrete that is highly flowable and workable for extended periods of time with normal setting characteristics. By varying the dosage rate,UltraFlo® products can be used as a normal, mid-range and high-range water-reducing admixtures.

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Development of High Early-Strength Concrete for Accelerated ...

2.1.4 Chemical Admixtures . ... 4.4 High Range Water Reducing Admixture Dosage Analysis . ... Construction Closure Pours in New England . ... rather than conventional or mid-range water reducers as defined by ACI Committee E-701. 由 S Castine 著作 · ‎2017 · ‎被引用 1 次 · ‎相關文章

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Water-Reducing Admixture - an overview | ScienceDirect Topics

The different ways to use high-range water-reducing admixtures, shown in Figure 16.1, result in either a reduced yield stress at constant solid content or water content or in an increase of the solid content (or decrease of the water-to-cement [w/c] ratio) at constant yield stress (Ramachandran et al., 1998).A variety of applications can be achieved by decreasing the w/c and at the same time ...

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Material Matters: Water-Reducing Admixtures - NPCA

Today, 95% of precasters use third-generation high-range water reducers, or superplasticizers, which are Type F. There is also an entire category of mid-range water reducers that isn’t classified or specified by ASTM. Doug Wittler, president of Premiere Concrete Admixtures based in Pioneer, Ohio, explains: “Developed in the 1990s originally ...

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Superplasticizer - Wikipedia

Superplasticizers (SP's), also known as high range water reducers, are additives used in making high strength concrete. Plasticizers are chemical compounds that enable the production of concrete with approximately 15% less water content. Superplasticizers allow reduction in water content by 30% or more.

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What are various types of Admixtures? - Civil Engineering

1. Plasticizers or water reducing agents 2. Superplasticizers or high range water reducers 3. Accelerators 4. Retarders 5. Air entrainers 6. Others. 1. Plasticizers – These are used to improve the plasticity of fresh concrete by reducing water content without affecting the workability and water cement ratio. Types of plasticizers include ...

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HIGH RANGE WATER-REDUCING CONCRETE ADMIXTURE

HIGH RANGE WATER-REDUCING CONCRETE ADMIXTURE DESCRIPTION Sikament® NN KH is a highly effective dual action li- ... Fresh concrete must be cured properly and curing applied as early as pos-sible. Concrete Mix Design When using Sikament® NN KH, a suitable mix design must be calculated.

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CON 122 Session 4 - Water Reducing & Set Controlling ...

2012年7月2日 — CON 122Concrete AdmixturesSession 4Water Reducing Admixtures &Set ... Deck Pours Long Hauls Particularly, with Extended-Set Control Admixtures ... Benefits of Water Reducers Fresh Concrete properties: Lower ... High-Range Water-Reducing Admixtures ASTM C 494 or AASHTO M 194  ...

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(PDF) Effect of welan gum-high-range water reducer ...

rheology-modifying admixtures increase the pseudo-plastic and. thixotropic behavior of ... Keywords: bleeding; cement grout; high-range water reducer; polysaccha- ... mL sample of fresh grout was poured inside a sealed steel. container, and ...

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Study of workability of fresh concrete using high range water ...

DOI: 10.5897/IJPS11.003 Corpus ID: 14103302. Study of workability of fresh concrete using high range water reducer admixtures @article{am2012StudyOW, title={Study of workability of fresh concrete using high range water reducer admixtures}, author={Ayhan Şam and M. V. Gouml and kccedil}, journal={International Journal of Physical Sciences}, year={2012}, volume={7}, pages={1097-1104} }

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portland cement concrete - FDOT

cement concrete to the site of placement in a freshly mixed, unhardened state. ... High Range Water-Reducer retarder admixture, Type G, to normalize the setting ...

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Information on the Properties of Pumpable Concrete - Canusa

Admixtures such as air-entrain- ... fresh concrete behaves depends on properties and proportions of the ma- ... High-range water reducers or superplasticizers can ... a lot of headaches and problems, especially on the first few pours for a.

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Admixtures for Concrete, Chapter 6

thermore, the workability of fresh concrete is improved significantly, and ... Superplasticizers are also referred to as high-range water reducers or plasticizers. 缺少字詞: Pouring ‎| 必須包含以下字詞: Pouring

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Sika® ViscoCrete®-10

Sika® ViscoCrete®-10 is added to the gauging water or added with it into the concrete mixer. To take advantage of the high water reduction, a wet mixing time, which is depending on the mixing conditions and mixer performance, of at least 60 seconds per cubic metre after the admixture …

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Types of Admixtures for Concrete - The Concrete Network

Nov 03, 2020 · Keep concrete workable during placement. High-Range water reducers (superplasticizers) Can reduce water content from 12% to as much as 40% and are typically used in concretes designed to have slumps of 8 to 11 inches. They can be used to either increase slump (by 4 to 8 inches) or lower the water content of hot weather concrete mixes.

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ARACO Admixture & Construction Material S.A.R.L

Admixtures. Pouring fresh concrete is time-sensitive in which unexpected delays can cause significant problems. Araco Admixtures provide enhanced cement dispersion resulting in improved concrete flowablility for low water/cement ratio. These specially formulated high-range water-reducing admixtures impart rheoplastic qualities to concrete ...

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What are Concrete Admixtures? | Liberty Ready Mix Des Moines

Water Reducing Admixtures are used for two different reasons. (1) To lower water content in fresh concrete and to increase its strength. (The more water added to concrete will weaken the strength of the concrete once it has cured) (2) To obtain a higher slump without adding additional water and increasing workability. High Range Water Reducers ...

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IC-QA-B80 - Concrete Work for Bridges - Roads and Maritime ...

2020年6月22日 — New provisions for curing added. Table B80.7 Previous Table B80.6. ... Initial slump value for HRWR admixture ... (viii) For concrete containing high range water reducers: final slump and reversion time. ... the range of days of the pours to demonstrate that there will be no adverse effects on the plastic.

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High Range Water Reducing Admixture for Concrete

High range water reducing admixture (ASTM C494 types F and G) decreases the water-cement ratio and provides high-performance, particularly at early ages. High range water reducing admixture reduces the quantity of mixing water required to produce concrete of a given consistency by 12 % or greater, as per ASTM C 494- C 494M.

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How to Use Admixtures for Cold Weather Concrete

Superplasticizers- These are high range water reducers. Superplasticizers can reduce water content of a concrete mix by 10% – 30%. Because this additive allows cement to maintain it’s workability, it’s a great option when easy-to-place concrete is still preferred.

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Concrete Admixtures - How to Use Admixtures in Concrete ...

Types of admixtures for concrete and concrete mix design. ... Pouring fresh concrete is a time-sensitive project and unexpected delays can cause major problems. ... and improve durability; Water reduction in the mix; Mid-range water reducers ...

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Materials Selection Guide: Water-Reducing Admixtures ...

Dec 05, 2006 · These admixtures, marketed as midrange water reducers, can provide water reduction up to 12% and often meet the requirements of ASTM C 494 for Type A water-reducing admixtures. Superplasticizers. High-range water reducers (HRWR), also known as superplasticizers are covered in ACI 212.4.

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Retarding Admixture - an overview | ScienceDirect Topics

Water-reducing admixtures are chemical admixtures designed to reduce the water:cement ratio of concrete without adversely affecting the rheological properties. Most of these water-reducing admixtures comply with the requirements of ASTM C494/C494M-17 (2017) as Type A, water-reducing, or Type F, high-range water-reducing mixtures.

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Chemical Admixtures — What, why, & how? – Nevada Ready Mix

Mid-range water reducers are now commonly used, and they have a greater ability to reduce the water content. These admixtures are popular as they improve the finishability of concrete flatwork. Mid-range water reducers must at least meet the requirements for Type A in ASTM C 494 as they do not have a separate classification in an admixture ...

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Admixtures for Cold Weather Concreting | Allied Concrete

Air entrainment also leads to increased workability and general durability of the concrete. Superplasticsers. Superplasticsers are high range water reducers. These can lead to a 10% - 30% reduction in the water content of a given concrete mix, but with workability characteristics of a normal slump mix still retained.

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