research concrete pumping effects on entrained airvoids

Research - Concrete Pumping Effects on Entrained Air-Voids ...

Jul 02, 1994  Concrete Pumping Effects on Entrained Air-Voids. Pumping is a frequently used method of efficiently transporting concrete from the delivery vehicles to the formwork. Unfortunately, pumping concrete can affect the air content of a concrete mix. This has caused concern about the possible loss of resistance of the concrete to freezing and thawing.

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Concrete Pumping Effects on Entrained Air-Voids

Concrete Pumping Effects on Entrained Air-Voids Author: William Elkey, Donald J. Janssen, Kenneth C. Hover Subject: Admixtures, Air entraining agents, Air voids, Fly ash, Freeze thaw durability, Lignosulfonate, Mix design, Pressurization, Pumped concrete, Stability \(Mechanics\), Water reducing agents Keywords

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Appendices: Concrete Pumping Effects on Entrained Air-Voids

Jul 02, 1994  Unfortunately, pumping concrete can affect the air content of a concrete mix. This has caused concern about the possible loss of resistance of the concrete to freezing and thawing. The actual effect of pumping on the air content measured for the concrete is not consistent; in some cases air content has increased, while in others it has decreased.

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Appendices: Concrete Pumping Effects on Entrained Air-Voids

Appendices: Concrete Pumping Effects on Entrained Air-Voids Author: ... Freeze thaw durability, Lignosulfonate, Mix design, Pressurization, Pumped concrete, Stability \(Mechanics\), Water reducing agents Keywords: concrete pumping, pressure, air voids, entrained air, freezing and thawing, spacing factor, specific surface, Philleo factor

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CONCRETE PUMPING EFFECTS ON ENTRAINED AIR-VOIDS. FINAL

CONCRETE PUMPING EFFECTS ON ENTRAINED AIR-VOIDS. FINAL REPORT. Pumping is a frequently used method of efficiently transporting concrete from the delivery vehicles to the formwork. Unfortunately, pumping concrete can affect the air content of a concrete mix. This has caused concern about the possible loss of resistance of the concrete to ...

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Concrete pumping and its effect on the air void system ...

Jul 05, 2018  10%  Pumping is the most utilized concrete placement technique on construction sites around the globe. Despite being used since the 1960s, a large portion of the knowledge related to the understanding of the concrete pumping process—especially with a focus on the effect of pumping on the concrete air void system—was generated through experience, and thus creating a need for a research

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INFLUENCE OF PUMPING ON CHARACTERISTICS OF AIR-VOID

INFLUENCE OF PUMPING ON CHARACTERISTICS OF AIR-VOID SYSTEM OF HIGH-PERFORMANCE CONCRETE. The results of an experimental study in which a high-performance air-entrained concrete mixture (water-cement ratio = 0.29; 28-day average compressive strength of 75 MPa) was pumped at the job site horizontally and vertically are presented.

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Influence of Pumping on Characteristics of Air-Void System ...

30 TRANSPORTATION RESEARCH RECORD 1478 Influence of Pumping on Characteristics of Air-Void System of High-Performance Concrete R. PLEAU, M. PIGEON, A. LAMONTAGNE, AND M. LESSARD The results of an experimental study in which a high-performance air­ entrained concretemixture (water-cement ratio= 0.29; 28-day average

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Development of a Robust Field Technique to Quantify the ...

Concrete Pumping Effects on Air-Entrained Voids in Concrete Mixtures [PDF - 1.18 MB] ... Published Date: 2019-05-01 Abstract: Placing concrete using a concrete pump has placement advantages due to the increased speed, accessibility, and convenience of operation. ... Office of the Assistant Secretary for Research and Technology (OST-R) U.S. DOT ...

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Welcome to ROSA P

The research described in this report investigated the impact concrete pumping has on air-entrained voids in concrete. The study examines the effects of different air contents, pumping time, and pressure has on the air volume and the stability of the air void system. The laboratory tests conducted show a significant amount of air volume was ...

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Influence of Pumping on Characteristics of Air-Void

30 TRANSPORTATION RESEARCH RECORD 1478 Influence of Pumping on Characteristics of Air-Void System of High-Performance Concrete R. PLEAU, M. PIGEON, A. LAMONTAGNE, AND M. LESSARD The results of an experimental study in which a high-performance air­ entrained concretemixture (water-cement ratio= 0.29; 28-day average

get price

Concrete pumping and its effect on the air void system ...

Jul 05, 2018  Pumping is the most utilized concrete placement technique on construction sites around the globe. Despite being used since the 1960s, a large portion of the knowledge related to the understanding of the concrete pumping process—especially with a focus on the effect of pumping on the concrete air void system—was generated through experience, and thus creating a need for a research

get price

INFLUENCE OF PUMPING ON CHARACTERISTICS OF AIR-VOID SYSTEM ...

INFLUENCE OF PUMPING ON CHARACTERISTICS OF AIR-VOID SYSTEM OF HIGH-PERFORMANCE CONCRETE. The results of an experimental study in which a high-performance air-entrained concrete mixture (water-cement ratio = 0.29; 28-day average compressive strength of 75 MPa) was pumped at the job site horizontally and vertically are presented.

get price

Development of a Robust Field Technique to Quantify the ...

Concrete Pumping Effects on Air-Entrained Voids in Concrete Mixtures [PDF - 1.18 MB] ... Published Date: 2019-05-01 Abstract: Placing concrete using a concrete pump has placement advantages due to the increased speed, accessibility, and convenience of operation. ... Office of the Assistant Secretary for Research and Technology (OST-R) U.S. DOT ...

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I. RESEARCH PROJECT TITLE: Best Practices for Concrete ...

affect the entrained air voids before and after pumping. This project has the objectives of determining how changes in different materials allowed in low-cracking high-performance concrete (LC-HPC) mixtures affect the concrete rheology and air systems. The project will also go to concrete field placements with pumping to determine

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Vibration Study of Consolidation of Portland Cement

Entrapped air voids are actually detrimental to the concrete, since they reduce the strength of the PCC (3). In addition they are a potential reservoir for water that can later freeze inside the concrete. Entrained air voids are very small in size. Entrained air ranges from 10 µm to 1000 µm (0.0004 to 0.04 inches) in diameter.

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Impact of Concrete Placing Method on Air Content, Air-Void ...

Jan 01, 1996  Concrete Pumping Effects on Entrained Air Voids. Final Report, Research Project T9233 Task 21, for the Washington State Transportation Commission, Washington State Transportation Center, University of Washington, Seattle, June 1994, 97 pp. Google Scholar

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AIR-ENTRAINMENT PROBLEM IN SELF-COMPACTING

concrete by frost are not perfectly clear, one of the ways to prevent internal cracking and disruption due to freezing and thawing cycles is known: it is simply ensuring that hardened concrete has an adequate system of entrained air voids. In accordance with the PN-EN 206-1, using air-entrainment as a basic way of assuring frost-resistance of

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A CRITICAL APPRAISAL OF THE AIR- ENTRAINMENT IN

The general effects of air entrainment are to increase the consistency, workability durability, decrease density (unit weight), decrease strength and reduce bleeding segregation. Air entrained concrete is more resistant to weathering cycles than plain concrete. Air entrainment leads to possible reduction in the sand content of the mix

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Modeling of water transport in highly saturated concrete ...

Jan 01, 2019  In Table 2, the effect of entrapped and entrained air is considered in the hydraulic model. The representative radii (r E) of empty pores are based on the empirical pore size for non-air entrained and 6% air entrained concrete .

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Entrained Concrete - an overview ScienceDirect Topics

Tony Binns, in Advanced Concrete Technology, 2003. Air-entraining agents. The small air bubbles in air-entrained concrete behave like fine fines and can, accordingly, compensate for the lack of this size of material in coarse sand.The ability of air-entrainment to increase cohesion is well-established. Concrete that would normally be unpumpable due to low cohesion may be improved by the ...

get price

(PDF) Effects of Strength, Permeability ... - Share research

Effects of Strength, Permeability, and Air Void Parameters on Freezing-Thawing Resistance of Concrete with and Without Air Entrainment Journal of ASTM International, 2009 Gilson R. Lomboy

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The Effect of Air-Entrainment on a Pumped, High ... - Concrete

Jul 01, 1997  The concrete was a modified normal density concrete where a portion (45% by volume) of the normal weight coarse aggregate was replaced with structural lightweight aggregate to reduce the concrete density. High slumps (210-230mm) were used to facilitate pumping, and to accommodate extremely congested reinforcing bar situations.

get price

Welcome to ROSA P

The research described in this report investigated the impact concrete pumping has on air-entrained voids in concrete. The study examines the effects of different air contents, pumping time, and pressure has on the air volume and the stability of the air void system. The laboratory tests conducted show a significant amount of air volume was ...

get price

INFLUENCE OF PUMPING ON CHARACTERISTICS OF AIR-VOID SYSTEM ...

INFLUENCE OF PUMPING ON CHARACTERISTICS OF AIR-VOID SYSTEM OF HIGH-PERFORMANCE CONCRETE. The results of an experimental study in which a high-performance air-entrained concrete mixture (water-cement ratio = 0.29; 28-day average compressive strength of 75 MPa) was pumped at the job site horizontally and vertically are presented.

get price

Development of a Robust Field Technique to Quantify the ...

Concrete Pumping Effects on Air-Entrained Voids in Concrete Mixtures [PDF - 1.18 MB] ... Published Date: 2019-05-01 Abstract: Placing concrete using a concrete pump has placement advantages due to the increased speed, accessibility, and convenience of operation. ... Office of the Assistant Secretary for Research and Technology (OST-R) U.S. DOT ...

get price

The Effect of Air-Entrainment on a Pumped, High ... - Concrete

Jul 01, 1997  The concrete was a modified normal density concrete where a portion (45% by volume) of the normal weight coarse aggregate was replaced with structural lightweight aggregate to reduce the concrete density. High slumps (210-230mm) were used to facilitate pumping, and to accommodate extremely congested reinforcing bar situations.

get price

Vibration Study of Consolidation of Portland Cement

Entrapped air voids are actually detrimental to the concrete, since they reduce the strength of the PCC (3). In addition they are a potential reservoir for water that can later freeze inside the concrete. Entrained air voids are very small in size. Entrained air ranges from 10 µm to 1000 µm (0.0004 to 0.04 inches) in diameter.

get price

Modeling of water transport in highly saturated concrete ...

Jan 01, 2019  In Table 2, the effect of entrapped and entrained air is considered in the hydraulic model. The representative radii (r E) of empty pores are based on the empirical pore size for non-air entrained and 6% air entrained concrete .

get price

AIR-ENTRAINMENT PROBLEM IN SELF-COMPACTING

concrete by frost are not perfectly clear, one of the ways to prevent internal cracking and disruption due to freezing and thawing cycles is known: it is simply ensuring that hardened concrete has an adequate system of entrained air voids. In accordance with the PN-EN 206-1, using air-entrainment as a basic way of assuring frost-resistance of

get price

(PDF) Effects of Strength, Permeability ... - Share research

Effects of Strength, Permeability, and Air Void Parameters on Freezing-Thawing Resistance of Concrete with and Without Air Entrainment Journal of ASTM International, 2009 Gilson R. Lomboy

get price

A CRITICAL APPRAISAL OF THE AIR- ENTRAINMENT IN

The general effects of air entrainment are to increase the consistency, workability durability, decrease density (unit weight), decrease strength and reduce bleeding segregation. Air entrained concrete is more resistant to weathering cycles than plain concrete. Air entrainment leads to possible reduction in the sand content of the mix

get price

Entrained Concrete - an overview ScienceDirect Topics

Tony Binns, in Advanced Concrete Technology, 2003. Air-entraining agents. The small air bubbles in air-entrained concrete behave like fine fines and can, accordingly, compensate for the lack of this size of material in coarse sand.The ability of air-entrainment to increase cohesion is well-established. Concrete that would normally be unpumpable due to low cohesion may be improved by the ...

get price

Frontiers Characterization of Air Dissolution and ...

Apr 25, 2019  Concrete pumping is the most used technique to transfer concrete from the mixer truck to the formwork. Numerous studies have been performed on the flow behavior of concrete in pipes, as well as the consequences of pumping on fluid and hardened concrete properties. One of the negative consequences of pumping concrete is a decrease in freeze-thaw resistance.

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Controlling Air Content in Concrete That is Being Pumped ...

Joint Transportation Research Program JTRP FHWA/IN/JTRP-98/11 FinalReport ControllingAirContentinConcreteThatisBeing Pumped,ASynthesisStudy CharlesF.Scholer ...

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Stability of air bubbles in fresh concrete

2.2.2 Air entraining agent in fresh concrete 4 2.3 Factors affecting air entrainment in concrete 5 2.3.1 Mixing 5 2.3.2 Mixture 5 2.3.3 Temperature 6 2.3.4 Other factors 7 2.4 Some observations of air entrainment in fresh concrete 7 2.4.1 Effect of entrained air on concrete properties 7

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Effect of Air Entrained Concrete on Strength of Concrete

1. Effect of Air Entrainment on Concrete Compressive Strength Air entraining admixture is usually introduced when it is desired to increase concrete workability without affecting much reduction in compressive strength. It is claimed that, the place-ability of an air entrained concrete having 7.5 cm slump is better than a non-air entrained ...

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