Air Entrainer is used to develop a large number of small air bubbles in the concrete (diameter less than 300 micron) which are homogeneous and stable after the mixing process.
Air Entrainer will reduce concrete strength.
Applications of Air Entrainer: Ready mix concrete, Structural concrete, Mass concrete, Paving concrete, and All exterior concrete subjected to freeze/thaw cycling.
SYNONYMS:
Air Entrainment Agent, Concrete Air Entrainer, Cement Additive, Micro-Air Bubble Agent, Concrete Foam Agent, Air-Entraining Admixture, Air Bubble Agent, Air-Entraining Agent
Air Entrainer is defined as the vertical location at which all the excess unburned fuel is consumed by the air entrained into the flame envelope.
Air Entrainer modifies the rheology of concrete and its durability to freezing and thawing cycles.
Air Entrainer network is characterized by the total volume of entrained air expressed, the diameter of the bubbles, the spacing factor (which represents the average half-distance between two adjacent air bubbles), and the average surface volume.
Like cement particles, entrained air bubbles have a diameter varying from 1 to 100 μm; on the contrary, coarse-entrapped air bubbles have a diameter similar to that of sand particles.
Parameters of formulation, cement type and fineness, concrete consistency, superplasticizer dosage, presence of supplementary cementitious materials, use of other types of admixtures, use of fibers, mixing, and transportation techniques influence Air Entrainer.
Air Entrainer bubbles must remain stable during transportation, placing, pumping, and finishing.
Usually, Air Entrainer is not difficult to fix the formulation of a mix by trial and error and produce a network of entrained air bubbles that satisfy design requirements.
Air Entrainer is surface active chemicals which cause small stable bubbles of air to be formed uniformly through a concrete mix.
The bubbles are mostly below 1 mm diameter with a high
proportion being below 0.3 mm.
Air is incorporated into concrete by the use of an Air Entrainer admixture (also called an air-entraining agent) that is added to the fresh concrete in controlled amounts, either at the batch plant or on the jobsite.
The amount of air in a mix can be adjusted as needed to meet specific job requirements and exposure conditions.
USES and APPLICATIONS of AIR ENTRAINER:
Construction Industry: Air Entrainer enhances air entrainment in concrete and mortar to improve workability and durability.
Concrete Admixtures: Air Entrainer reduces freeze-thaw damage in structures exposed to harsh climates.
Air Entrainer improves resistance to scaling and chemical attacks.
Special Applications: Air Entrainer is used in lightweight concrete formulations for insulation and acoustic purposes.
Air Entrainer is used to develop a large number of small air bubbles in the concrete (diameter less than 300 micron) which are homogeneous and stable after the mixing process.
The incorporated air bubbles have several effects on the fresh and the hardened concrete.
In the fresh state, the concrete mix is stabilised and by the “ball bearing effect” of the bubbles the workability may be increased, especially in low cement content or dry mixes.
Air Entrainer can also significantly reduce any tendency for the mix to bleed.
In the hardened state the remaining air bubbles interrupt the porous system of the concrete, reducing the capillary suction (water adsorption).
The bubbles act as an expansion area for freezing water in the pore system leading to increased freeze-thaw resistance.
Air Entrainer admixtures facilitate the development of a system of microscopic air bubbles within concrete during mixing.
Air Entrainer increases the freeze-thaw durability of concrete, increase
resistance to scaling caused by deicing chemicals, and improve workability.
Air Entrainer will reduce concrete strength.
As a general rule, a 1% increase in the concrete Air Entrainer content will decrease the 28-day compressive strength by about 3 to 5%.
Applications of Air Entrainer: Ready mix concrete, Structural concrete, Mass concrete, Paving concrete, and All exterior concrete subjected to freeze/thaw cycling.
-Air Entrainer agents
Air Entrainer rapidly entrains ultra-stable micro air voids, improving the workability and long-term durability of your end product.
As one of the most efficient Air Entrainer on the market, you’ll achieve superb cost effectiveness plus exceptional performance.
-Air Entrainer is used by themselves or teamed-up with other concrete additives to enhance concrete properties.
Far from being an extra cost, Air Entrainer agents have established themselves in the concrete industry with serious players as a must-have to:
*Improve workability,
*Reduce bleeding, and
*Increase the freeze thaw resistance of concrete.
-Improve Workability of Concrete with an Air Entrainer:
One way to increase the workability of cementitious mixes is by simply adding more water.
By increasing the water to cement ratio, the mixture becomes more fluid.
But that decision comes with its own set of problems – like the bleeding of concrete.
So, it’s time to improve workability with better methods.
With Air Entrainer enabled, the air bubbles within the mixture act as a lubricant within the concrete mix.
Thus, increasing the fluidity.
The enhanced workability enables the mixture to be pumped and transported to its intended location within the construction site with better efficiency.
A pro tip is to include an Air Entrainer in the concrete mix design especially when using artificial sand.
Differently from natural sand, artificial sand is less spherical and irregularly shaped.
Applying the same principle as explained before, the entrained bubbles enhance fluidity of a concrete mixture with artificial sand.
Air Entrainer can Decrease Bleeding of Water in Concrete
In short, bleeding occurs when water rises to the surface of freshly poured concrete.
Essentially, concrete is composed of four materials: cement, sand, stone and water.
Water is the only liquid and the least dense of these four ingredients.
Thus, water that was not absorbed into cement or sand tends to rise above the denser materials of the mixture.
The result is a puddle of water that “bled” to the surface of freshly poured concrete.
Enabled by Air Entrainer, air bubbles increase the surface area water and cement need to cover.
The outcome is a more balanced mixture, which has less water rising to the surface of freshly placed concrete.
-Increase Freeze Thaw Resistance by adding an Air Entrainer to the Concrete Mix Design
Water can do amazing things for concrete, but it can also cause damage.
Concrete that was not properly prepared for climate variations can suffer from the extreme heat and cold.
In regions where negative temperatures occur, concrete needs to be able to resist the freeze thaw cycle.
The main reason Air Entrainer is added to concrete mix design is to increase its freeze thaw resistance.
The air bubbles created through Air Entrainer act as “expansion chambers” for water.
WHY DOES WATER NEED SPACE TO EXPAND?
Because frozen water occupies 9% more volume than water at room temperature.
If Air Entrainer did not happen, frozen water will make space for itself by creating minuscule cracks within concrete.
Over time, this repeated cycle of freezing and melting of water causes micro fractures to become large-scale problems.
Thus, by simply adding Air Entrainer to the concrete mix design, the resistance to freeze thaw can be greatly increased.
WHAT ARE THE BENEFITS OF AIR ENTRAINER IN CONCRETE?
The primary benefit of Air Entrainer is the resistance it gives hardened concrete to freeze-thaw damage and spalling caused by deicing salts or chemicals.
However, Air Entrainer offers other advantages as well:
It makes concrete more durable and reduces the potential for shrinkage and crack formation.
In fresh concrete, Air Entrainer acts as a lubricant, making concrete more plastic and easier to spread and finish.
Air Entrainer concrete tends to be more cohesive and uniform, resulting in a reduction in bleeding and segregation.
For more information about the benefits of Air Entrainer, see Protect Against Freeze-Thaw Cycles to Improve Durability.
WHAT IS AIR ENTRAINER CONCRETE?
Air Entrainer concrete contains microscopic air bubbles that help alleviate internal pressure on the concrete by providing small pockets for water to expand into when exposed to freeze-thaw conditions.
Without these pockets water has no place to escape, leading to cracks and/or scaling in concrete that greatly diminish the lifespan of a structure.
Air is applied into a concrete mix via an Air Entrainer admixture otherwise known as AEA.
The amount of Air Entrainer in a mix can be adjusted to meet the specifications of the job at hand.
WHAT IS AIR ENTRAINER AND WHAT AIR ENTRAINER DOES?
In simplest terms, Air Entrainer admixtures are surfactants, such as soap.
They interact with the alkalinity of concrete to produce huge volumes of small spherical air bubbles that typically range from 0.006 to 0.008 inch in diameter.
Ideally they are spaced no more than about 0.008 inches apart or less.
When Air Entrainer is added to concrete, there is some effect on slump, and compressive strength is reduced by about 500 psi in a standard 6-bag (564-pound) mix.
There are two kinds of air in concrete: entrapped and entrained.
Entrapped air is a result of the mixing process.
As concrete is being mixed about 1.5% air becomes entrapped.
The bubbles are shaped irregularly and have no effect on the concrete's durability because they are too large, easily seen by the eye.
Entrained bubbles are the opposite.
They are spherical, are best viewed under a microscope, and provide durability under freeze/thaw conditions.
When you measure air in concrete, the percentage reading represents the total amount of Air Entrainer and entrained air.
For example, if the reading on an air meter is 6% air, it means that approximately 1.5% of the total is entrapped air and 4.5% is Air Entrainer.
Though readings are reported always as percentages, the percentage number isn't what really counts.
It's the size of the entrained bubbles and the space between them that is important.
This usually is determined by petrographic analysis of hardened concrete.
So percentage numbers provide approximate results.
Different mixes, depending on aggregate sizes and the amount of cement powder in a mix, have different percentage requirements.
For example, one mix might need 6% air while another needs only 4%.
In each case, the bubble size and spacing should be the same.
When a pressure test isn't performed correctly, the error usually results in higher readings.
Air Entrainer is used for three primary reasons.
Air Entrainer always is specified for concrete exposed to freeze/thaw conditions.
Occasionally, Air Entrainer is used to prevent bleeding—water coming to the surface of freshly placed concrete (remember, water is required to make bubbles).
Air Entrainer also is used to reduce unit weights of concrete, especially for lightweight aggregate mixes, reducing unit weight beyond what the aggregates can provide.
FEATURES OF AIR ENTRAINER
Adjusting Air Entrainer
How to manage the most difficult admixture on the jobsite
It's possible that you as a contractor will never have to face up to the problems that Air Entrainer can cause when it's either too high or too low in concrete.
Hopefully this information also will cause you to think more proactively to resolve problems involving Air Entrainer before concrete is placed.
Air Entrainer admixtures can be troublemakers, but necessary ones.
By a wide margin, Air Entrainer creates more problems for ready-mix producers, contractors, and owners than all the other admixtures.
Almost everything influences them: ambient and concrete temperatures, the time Air Entrainer takes a ready-mix truck to travel from the batch plant to the jobsite, mixing time, the configuration of the mixing drum and the condition of the mixing blades, the water-cement ratio of a mix, the type of portland cement used, and other admixtures (especially polycarboxylate superplasticizers), to name a few.
When Air Entrainer is too high, contractors can experience problems when they finish it, especially when troweling machines are used.
Too much air also can cause problems when contractors stamp decorative patterns in concrete.
Concrete installed outdoors in freeze/thaw climates without adequate Air Entrainer is especially susceptible to scaling during the first or second winter.
Placing concrete with too much or too little Air Entrainer becomes the contractor's problem.
Even if tests eventually determine that others are responsible, the concrete contractor is invariably the one to face an upset owner, experience cash flow issues, and possibly have to remove and replace work at their own expense.
With this in mind, measuring and adjusting Air Entrainer when concrete (especially first loads) arrives on the jobsite becomes a way to manage risk.
HOW DO AIR ENTRAINER ADMIXTURES WORK?
Air Entrainer admixtures do not generate bubbles.
Air Entrainer simply stabilizes microscopic bubbles that are created during the mixing process by:
1) reducing the surface tension of the mixing water to promote the development of the microscopic bubbles;
2) stabilizing the bubbles by forming a sturdy shell that
repels water, hinders their coalescence, and promotes attraction to cement and aggregate particles
WHAT IS AIR ENTRAINER IN CEMENTITIOUS MIXES?
Air Entrainer is created by design.
This process consists of producing air bubbles within the concrete mix though mechanical agitation.
But these are not common air bubbles that are irregular and visible to the naked eye.
Air Entrainer bubbles are microscopic, innumerous, and spherical.
Also, they have an evenly spaced distribution.
Entrained air bubbles usually maintain a distance of 0.25 mm between each other.
In addition, 4% to 6% of these well-distributed air bubbles can be incorporated into cementitious mixtures.
WHY DO I NEED AIR ENTRAINER IN CONCRETE?
In cold weather climates, water within the concrete capillary
pores will freeze and expand when the temperature drops below freezing.
If the concrete is critically saturated (>91.7%), the expansion of ice (~9% in volume) exerts pressure within the hardened concrete and will cause cracking if the tensile strength of the concrete is exceeded.
Air Entrainer voids spaced within the concrete provide a place for the freezing / expanding water to move into, which relieves the pressure and thereby prevents cracking.
TYPES OF AIR ENTRAINER:
There are two general classifications today—wood-derived acid salts (Vinsol resins) and synthetic resins.
Vinsol resins have been on the market the longest and many ready-mix producers continue to use them because they are familiar with them.
They work especially well with very low water-cement mixes, developing good bubble structures—and are ideal for road pavements.
But when slump exceeds 6 inches, including placing slumps when superplasticizers are added, entrainment readings begin to decrease.
Percentages also decrease the longer concrete mixes are in the truck.
After an hour in the truck, concrete can lose as much as 1% air (0.25% every 15 minutes) and more admixture should be added.
Synthetic resins have exotic generic names such as “fatty acids,” “gum resins,” and “tall oils” and have been in the marketplace for only a few years.
These admixtures can produce smaller bubble sizes spaced closer together than Vinsol resins, offering greater durability under freeze/thaw conditions.
But they also entrain more air as slumps increase, and can cause readings to be excessive.
For example if a wet load arrives on a jobsite with specified 6% Air Entrainer, or if your crew adds water to make 6-inch or higher slumps, air entrainment readings can increase to 20% and even higher, compromising other properties of the concrete.
You should measure the air before placing concrete under these conditions.
Air Entrainer Admixtures
- Reduced segregation and bleeding
- Increased resistance to damage from freezing and thawing
- Production of high-quality normal or lightweight concrete
Air Entrainer is a ready-to-use, aqueous solution made of organic materials.
Air Entrainer entrains a small and stable amount of air into the desired mix.
These small, stable air voids enhance the mixture and improve workability.
Its chemical composition and physical properties make it ideal for many construction applications.
It is intended for use when increased workability and freeze-thaw durability of concrete or mortar is preferred.
This admixture also improves resistance to freeze/thaw, scaling, segregation, and bleeding and improves strength, plasticity, water retention, and cohesiveness of mortar.
Meets ASTM C260 Standard Specification for Air Entrainer Admixtures for Concrete.
BENEFITS OF AIR ENTRAINER
Using an Air Entrainer admixture in concrete offers several benefits, particularly in enhancing the concrete’s durability and performance.
Air Entrainer admixtures significantly enhance concrete’s durability, workability, and resistance to various forms of environmental and chemical damage, making them an essential component in many concrete applications — particularly in regions with harsh weather conditions.
*Improved Freeze-Thaw Resistance:
As water freezes, it expands by approximately 9% by volume, causing pressures that can rupture concrete and cause scaling.
Air Entrainer admixtures create microscopic air bubbles within the concrete, providing space for water to expand when it freezes.
This reduces internal pressure and prevents cracking & spalling in freeze-thaw conditions.
*Increased Durability:
The presence of air bubbles enhances the concrete’s resistance to weathering and chemical attacks, leading to a longer lifespan for structures exposed to harsh environments.
*Enhanced Workability:
Air Entrainer concrete is easier to work with, as the microscopic bubbles improve the mix’s plasticity and cohesiveness.
This makes the concrete easier to place, finish, and compact.
*Reduced Bleeding and Segregation:
The uniform distribution of air bubbles helps to stabilize the mix, reducing the tendency for water and fine particles to separate from the aggregate.
This leads to a more uniform and stable concrete mix.
*Decreased Permeability:
The air voids created by the admixture reduce the concrete’s permeability, making it less susceptible to water penetration and the subsequent damage from cycles of freezing and thawing, as well as from chemical attacks.
*Enhanced Resistance to Sulfate Attack:
Air Entrainer concrete exhibits better resistance to sulfate attack, which can cause expansion and cracking.
The air bubbles help to mitigate the stress induced by sulfate reactions.
*Improved Surface Finish:
The improved workability and reduced bleeding contribute to a better-quality surface finish, with fewer defects such as scaling and crazing.
*Increased Scaling Resistance:
Air Entrainer concrete is more resistant to surface scaling caused by deicing salts and other chemical exposure, which is particularly beneficial for pavements, driveways, and other exposed surfaces.
*Reduced Risk of Alkali-Aggregate Reaction (AAR):
The air voids can help mitigate the effects of alkali-aggregate reactions, which cause expansion and cracking.
The Air Entrainer provides space for the reaction products to expand, reducing internal stress.
DRAWBACKS OF AIR ENTRAINER
While Air Entrainer admixtures offer significant benefits to concrete, such as improved durability and freeze-thaw resistance, they also come with some potential drawbacks:
*Reduced Strength:
Introducing air into the concrete mix decreases its overall density and can reduce the compressive strength of the concrete.
While the trade-off is often acceptable for the benefits gained in durability, it is still a crucial consideration in structural
applications where high strength is essential.
For every 1% of air that is added, approximately 3–5% of strength is lost.
*Increased Porosity:
The air voids created by Air Entrainer admixtures increase the porosity of the concrete.
This can potentially reduce the concrete’s resistance to abrasion, making it less suitable for surfaces subjected to heavy wear, such as industrial floors.
*Potential for Over-Entraining:
If too much air is introduced into the mix, it can lead to excessive air content, which significantly reduces concrete’s strength and durability.
Careful control & monitoring of air content are required to ensure optimal performance.
*Variability in Air Content:
Achieving consistent air content can be challenging due to variations in mixing, placing, and finishing techniques. Inconsistent Air Entrainer can lead to uneven performance and durability across different sections of the concrete.
*Cost:
Air Entrainer admixtures add to the cost of the concrete mix. While this is often justified by the benefits provided, it can be a concern for projects with tight budgets or where the benefits of Air Entrainer are not critical.
*Potential Compatibility Issues:
Air Entrainer admixtures need to be compatible with other admixtures used in the concrete mix.
Incompatibilities can lead to issues such as segregation, setting problems, or reduced effectiveness of the admixtures.
*Impact on Workability:
While Air Entrainer generally improves workability, in some cases, it can lead to overly cohesive mixes that may be more challenging to place and finish, especially in mixes with low water content.
*Surface Finish Concerns:
Excessive Air Entrainer can lead to surface defects such as scaling, spalling, or pop-outs, particularly in exposed concrete surfaces.
Proper finishing techniques are essential to mitigate these issues.
*Longer Curing Times:
In some instances, Air Entrainer concrete may require longer curing times to achieve desired strength and durability characteristics, potentially impacting project timelines.
While Air Entrainer admixtures provide significant advantages in durability and freeze-thaw resistance, they must be used carefully & with proper quality control to avoid potential drawbacks such as reduced strength, increased porosity, and variability in performance.
HOW MUCH AIR ENTRAINER DO I NEED?
The industry standard for Air Entrainer content in exterior concrete flatwork subject to freeze-thaw cycles and exposure to deicing chemicals is 6%, per ASTM C260, Standard Specifications for Air Content in Concrete.
But a leeway of +2% is permitted to account for variables such as concrete material proportions, mixing methods, and the temperature of the concrete, all of which can cause fluctuations in air content.
An exception to this 6% rule is decorative stamped concrete.
Because Air Entrainer can reduce bleed water, which is needed to wet out the color hardener, a 4% air content is often recommended (see Stamped Concrete Mix Recipe).
Anything less than 4% will not give concrete the durability needed to hold up to repeated freeze-thaw exposure.
WHAT HAPPENS IF THE AIR CONTENT IS TOO LOW?
If the ready-mix truck arrives at the job and an air content test determines that the percentage of air is lower than specified, all is not lost.
Rather than rejecting the concrete and sending the truck back, it’s possible to make corrections in the field by using a premeasured, prepackaged Air
Entrainer admixture that you can add directly to the truck mixer.
One bag will increase the entrained air content of a full load of concrete by as much as 1%.
WHAT ARE THE CONSEQUENCES OF NOT USING AIR ENTRAINER IN DECORATIVE CONCRETE?
No or low Air Entrainer in exterior concrete exposed to freeze-thaw conditions will result in poor durability and much greater vulnerability to the internal pressures caused when moisture in concrete freezes and expands.
The consequences of freeze-thaw damage can be particularly devastating to the appearance of stamped concrete.
They include ugly scaling and flaking of the surface, popouts, and cracking, all of which may continue to worsen with successive freeze-thaw cycles.
Even if the concrete has a dense color-hardened surface and is protected by a good sealer, it can still sustain damage if it becomes saturated and freezes.
The simplest way to avoid these problems is to add an Air Entrainer admixture to your concrete mix.
Depending on the exposure conditions in your area, you should aim for an air content of about 4% to 7%, or as recommended by your ready-mix supplier.
HISTORY OF AIR ENTRAINER:
Air Entrainer admixtures were discovered in the 1930s.
These admixtures for concrete were developed by researchers working for the U.S. Bureau of Public Roads (now the Federal Highway Administration) in the 1930s.
The discovery was made by R. E. Davis, R. W. Carlson, and L. H. Martin, who were investigating ways to improve the durability of concrete, especially in cold climates that are subject to freeze-thaw cycles.
Their work led to the development of these admixtures, which create small air bubbles within the concrete, significantly enhancing its resistance to freeze-thaw damage and improving its overall durability.
AIR ENTRAINER ADMIXTURES
Air Entrainer admixtures cause small stable bubbles of air to form uniformly through a concrete mix.
The bubbles are mostly below 1 mm diameter with a high proportion below 0.3 mm.
The benefits of Air Entrainer in the concrete include increased resistance to freeze-thaw degradation, increased cohesion (resulting in less bleed and segregation) and improved compaction in low-workability mixes.
The volume of Air Entrainer depends on the application and the mix design.
After mixing, Air Entrainer can be lost during transport and pumping.
Allowance should be made for this so that the correct level of Air Entrainer is obtained in the hardened concrete.
This may mean testing at the point of discharge rathr than at the batching plant.
Air Entrainer reduces the density of the mix and increases yield.
This needs to be taken into account when batching and mixing.
For every 1% of additional Air Entrainer, concrete strength will fall by around 5%.
At normal Air Entrainer levels, most other properties of the concrete including drying shrinkage and creep are not significantly affected.
The main reason for using Air Entrainer is to improve freeze-thaw and scaling resistance and so prolong service life.
Air Entrainer is used the improved cohesion and compaction and can also enhance quality and durability.
WHAT IS THE DIFFERENCE BETWEEN AIR ENTRAINER AND NON-AIR ENTRAINER CONCRETE?
Air Entrainer concrete is made from the same four components used to manufacture conventional concrete: cement, coarse aggregate, fine aggregate (or sand), and water.
The one difference is the addition of an Air Entrainer agent, sometimes considered to be the fifth essential ingredient in an exterior concrete mix.
Even when an Air Entrainer admixture isn’t used, concrete will contain a small percentage of air (about 1% to 2%) that is naturally entrapped within the concrete during mixing.
These entrapped air bubbles are larger and more irregular in shape than entrained air bubbles and contribute nothing to concrete durability and freeze-thaw resistance.
Entrapped air is also unstable and can be lost when the concrete is transported and placed.
DOES ALL EXTERIOR CONCRETE NEED AN AIR ENTRAINER ADMIXTURE?
Air Entrainer is a must for exterior concrete in areas of the country where frost-related damage can occur.
Air Entrainer is especially essential for concrete driveways that will be exposed to vehicle traffic and deicing salts .
Because Air Entrainer is beneficial to concrete in so many ways, it’s often recommended for exterior concrete in mild climates as well, even if there’s little concern about freezing and thawing.
IS AIR ENTRAINER CONCRETE HARDER TO PLACE AND FINISH?
There are no major differences between handling and placing of Air Entrainer concrete vs. non-Air Entrainer concrete, and many contractors will tell you that Air Entrainer concrete is easier to work with.
However, you may need to adjust your normal finishing operations because Air Entrainer can significantly reduce bleeding of the concrete.
That means floating and troweling may need to be completed sooner before the concrete surface becomes too stiff, especially on hot and windy days when moisture evaporates quickly.
PROPERTIES OF AIR ENTRAINER
*Facilitates uniform distribution of micro-air bubbles in concrete
*Reduces bleeding and segregation in cementitious mixes
*Improves the workability and pumpability of concrete
*Compatible with other concrete admixtures like water reducers and retarders
BENEFITS OF AIR ENTRAINER
*Increases freeze-thaw resistance, reducing cracking and spalling
*Improves concrete durability and longevity
*Enhances concrete's resistance to sulfates and salts
*Lightweight formulations reduce material use and cost
THE BENEFITS OF AIR ENTRAINER IN THE CONCRETE INCLUDE:
Air Entrainer is increased resistance to the action of freezing and thawing
Air Entrainer is increased cohesion resulting in less bleed and mix segregation.
Air Entrainer is improved compaction in low workability mixes.
Air Entrainer gives stability to extruded concrete
Air Entrainer gives improved cohesion and handling properties to bedding mortars.
ADVANTAGES OF AIR ENTRAINER CONCRETE:
Air Entrainerconcrete is key to freeze-thaw resistant concrete.
• Increased resistance to freeze-thaw conditions
• Increased workability
• Increased durability
• Increased resistance to chemical attack
• Increased cohesion
DISADVANTAGES OF AIR ENTRAINER CONCRETE:
• Strength loss
• Decreases in unit weight
• Potential honeycombing
Air Entrainer provides durable concrete resistant to ice and frost by creating stable, small, closely spaced air bubbles system.
Concrete durability research has established that the best protection for concrete from the adverse effects of freeze/thaw cycles and de-icing salts results from:
*proper Air Entrainer content in the hardened concrete
*a suitable air-void system in terms of bubble size and spacing
*adequate concrete strength, assuming the use of sound aggregates and proper mixing, placing, handling and curing techniques.
WHY DO WE USE AIR ENTRAINER CONCRETE?
It is beneficial to use Air Entrainer concrete when placing concrete in areas with freeze-thaw conditions.
Freeze-thaw conditions occur when the temperature of an environment fluctuates between above freezing temperatures and below freezing temperatures.
Additionally, Air Entrainer concrete provides scaling resistance and a prolonged service life.
It is important to use Air Entrainer concrete to avoid cracks in the concrete which later leads to increased deterioration of the structure.
TECHNICAL INFORMATION ABOUT AIR ENTRAINER:
For freeze-thaw protection, the air content of a concrete mix will typically be in the 5-7% range.
Depending on the amount of air specified, it will then be necessary to increase the cement content to achieve desired strengths.
Although these air bubbles are microscopic, when the amount of air in a concrete mix is increased it will weaken the concrete.
Generally, the use of Air Entrainer admixtures will lead to a strength reduction of about 5% for each 1% increase in the volume of air voids in a mix.
The reason why this occurs is because as more air is introduced to the mix the concrete becomes less dense as well as more of the concrete being air.
With more cement (the “glue” in concrete) a concrete mix will have more strength.
Therefore, if a concrete mix requires Air Entrainer there will typically be more cement in the mix to compensate for the strength loss.
WHAT ARE AIR ENTRAINER CONCRETE ADMIXTURES?
Air Entrainer concrete admixtures facilitate the development of a system of microscopic air bubbles within concrete during mixing.
The main reason for the use of Air Entrainer admixtures is to increase the resistance of concrete against the alternating freezing and thawing cycles of water.
TCC Materials carries multiple Air Entrainer products such as Akona Liquid Air Entrainer Admixture and Tenon Air Entrainment.
Both products are ready-to-use, aqueous solutions made of organic materials.
The products entrain a small and stable amount of air into the desired mix.
These small, stable air voids enhance the mixture and improve workability.
Its chemical composition and physical properties make it ideal for many construction applications.
It is intended for use when increased workability and freeze-thaw durability of concrete or mortar is preferred.
These admixtures also improve resistance to freeze/thaw, scaling, segregation, and bleeding and improve the strength, plasticity, water retention, and cohesiveness of mortar.
Meets ASTM C260 Standard Specification for Air Entrainer Admixtures for Concrete.
CHEMISTRY AND CLASSIFICATION OF ADMIXTURES OF AIR ENTRAINER
Air Entrainer is surface-active chemicals (surfactants) that consist of a water-repelling chain (nonpolar hydrocarbon) with a water-attractive chain (anionic polar).
The two major classifications of Air Entrainer admixtures are wood-derived acid salts (vinsol resins and wood rosins) and synthetic resins.
Wood-Derived Acid Salts
Develop good bubble structures
Used for more than 60 years
Work well with low watercementitious mixtures.
Tend to lose air with time/haul distance
Due to supply issues, wood rosins have replaced vinsol
resins in most markets.
Synthetic Resins
Can be detergents, fatty acids, gum resins, and tall oils
Have been in the marketplace since the mid-1980’s
Can produce smaller bubbles that are spaced closer together relative to bubbles formed by vinsol resins and
wood rosins; thus, offering greater durability under freeze/thaw conditions.
Can lead to increased air contents with delayed additions of water.
How do Air Entrainer improves concrete durability:
Increase resistance to damage from cyclic freezing and thawing
Increase resistance to scaling from deicing salts
Improve workability
Reduce segregation and bleeding
Air Entrainer is formulated for use as an air entraining admixture for concrete of all types and is manufactured under rigid control which assures uniform and precise performance.
Air Entrainer adds microscopic air bubbles in concrete and works especially well with high carbon fly ash.
Air Entrainer does not contain added chlorides and will not promote the corrosion of steel.
FEATURES AND BENEFITS OF AIR ENTRAINER
*Air Entrainer provides a stable air void system with proper bubble size and spacing which will increase durability
*Concrete is made more resistant to de-icing salts, sulfate attack and corrosive water
*Less mixing water can be used per yard (meter) of concrete and placeability is improved
*Minimizes bleeding and segregation of the concrete
PHYSICAL and CHEMICAL PROPERTIES of AIR ENTRAINER:
Chemical Name: Varies depending on the composition; commonly includes surfactants, fatty acids, or synthetic agents
EC Number: Specific to the formulation; often proprietary
CAS Number: Varies depending on the specific chemical composition (e.g., agents like Vinsol resin: 8050-09-7)
Appearance: Liquid, powder, or resin-like solid
Solubility: Generally soluble in water
Density: ~0.9–1.1 g/cm³ (varies with product)
pH (liquid form): ~7-9
Odor: Mild to negligible
FIRST AID MEASURES of AIR ENTRAINER:
-Description of first-aid measures
*General advice:
Show this material safety data sheet to the doctor in attendance.
*If inhaled:
After inhalation:
Fresh air.
*In case of skin contact:
Take off immediately all contaminated clothing.
Rinse skin with
water/ shower.
*In case of eye contact:
After eye contact:
Rinse out with plenty of water.
Call in ophthalmologist.
Remove contact lenses.
*If swallowed:
After swallowing:
Immediately make victim drink water (two glasses at most).
Consult a physician.
-Indication of any immediate medical attention and special treatment needed.
No data available
ACCIDENTAL RELEASE MEASURES of AIR ENTRAINER:
-Environmental precautions:
Do not let product enter drains.
-Methods and materials for containment and cleaning up:
Cover drains.
Collect, bind, and pump off spills.
Observe possible material restrictions.
Take up dry.
Dispose of properly.
Clean up affected area.
FIRE FIGHTING MEASURES of AIR ENTRAINER:
-Extinguishing media:
*Suitable extinguishing media:
Carbon dioxide (CO2)
Foam
Dry powder
*Unsuitable extinguishing media:
For this substance/mixture no limitations of extinguishing agents are given.
-Further information:
Prevent fire extinguishing water from contaminating surface water or the ground water system.
EXPOSURE CONTROLS/PERSONAL PROTECTION of AIR ENTRAINER:
-Control parameters:
--Ingredients with workplace control parameters:
-Exposure controls:
--Personal protective equipment:
*Eye/face protection:
Use equipment for eye protection.
Safety glasses
*Body Protection:
protective clothing
*Respiratory protection:
Recommended Filter type: Filter A
-Control of environmental exposure:
Do not let product enter drains.
HANDLING and STORAGE of AIR ENTRAINER:
-Conditions for safe storage, including any incompatibilities:
*Storage conditions:
Tightly closed.
Dry.
STABILITY and REACTIVITY of AIR ENTRAINER:
-Chemical stability:
The product is chemically stable under standard ambient conditions (room temperature) .
-Possibility of hazardous reactions:
No data available