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Concrete Casting News from the Hill and Griffith Company

Properly Applying Concrete Release Agents

Posted by Hill and Griffith Company on Dec 13, 2019 8:31:59 AM

Reprinted from the National Precast Concrete Association Tech Notes

Release agents, when properly used, aid in the stripping process, assist in producing sound defect-free concrete surfaces, simplify form cleaning and increase the working life of quality form surfaces.

There are two main categories of form release agents:
• Barrier – those that provide a physical barrier between the form and the concrete (such as petroleum-based products, soaps, synthetic resins, waxes) 
• Reactive – those containing fatty acids or other ingredients that react with the free lime in fresh concrete to produce a metallic soap interface between the form and the concrete (such as proprietary products and vegetable oils that are typically found in petroleum-based carrying agent products).

Concrete_From_Release_1.pngApplying Release Agents

Release agents should be applied to a clean form before the reinforcement has been placed to reduce the likelihood of inadvertently applying it to the reinforcement. If the release agent does come in contact with reinforcement it should be wiped clean before placing the concrete.

When applying a release agent it is best to follow the manufacturer’s instructions. When too much form release is used, it is not only wasteful and inefficient, but it leads to a number of other associated problems with the finished product. He who holds the wand determines the amount of material being applied, so proper training is crucial. As a rule of thumb, remember: Less is better. The amount needed to affectively coat a form is only about 0.005 inches thick. The actual cover thickness will depend on the application method and viscosity of the product, which is related to the ambient temperature. Typically, the colder it is in the plant, the thicker, or more viscous, the release agent will be. The warmer it is the plant, the thinner, or less viscous, it will be. Different measures can be taken during the application process to account for changes in material temperature (viscosity) throughout the year.

Spraying

Spraying is probably the most efficient and common method for applying release agents. Keep the wand moving when applying form release. Broad nozzle/ flat spray tips have been found to give the thinnest and most uniform cover. It should be noted that as the temperature drops and viscosity increases, the spraying pressure should be increased and the nozzle orifice size reduced. As temperatures rise, reduce pressure and increase nozzle size. It is a good practice to soak or mop up any puddles that may have formed at the bottom of the form Remember: Less is better. Only through experience and training will you learn what works best for your plant’s production line.

CAUTION: Fatty acids will react with brass, bronze, aluminum, grey ductile and malleable iron and mild steel, as well as some petroleum-based products used for making blockouts and other embedded items. It is best to use stainless steel, nickel or plastic for your spraying systems and to test for possible reaction of embedded materials prior to full implementation.

Swabbing and Painting

Swabbing and painting by hand is an acceptable application method, with the benefit of eliminating the majority of airborne particulate. On the negative side, applications tend to be thicker than necessary, leading to wasted material and the potential for additional problems.

Wiping

Wiping is often the method of choice for architectural precasters concerned with a blemish-free surface. Wiping on release agents with a sponge or rag will normally result in the thinnest coating, but it is very labor intensive.

Dipping

Automated dipping systems are fast, labor efficient and ensure complete coverage. Excess material will usually drip back into a holding tank, reducing material waste. The application coat is often thicker than necessary, however, again creating the potential for future problems.

Concrete_From_Release_2.pngSeasoning

Reactive form release agents, the most commonly used release agents in precast and pipe production, typically contain fatty acids. Fatty acids are mild acids composed of animal fats and vegetable oils. These fatty acids have a natural affinity for metal. They react with metal to form a protective barrier, which is a coating of metallic oleate. This process is known as seasoning. This protective layer prevents further application of fatty acids from migrating to the metal of the form and allows the fatty acid to remain on the surface of the form to react with the free lime on the surface of the casting. Seasoning serves two purposes. First, it enhances the easy separation of the form from the castings. Second, it enables free air to rise more easily on the vertical surfaces of the castings, resulting in fewer surface defects. Seasoning of forms is a very basic requirement to help minimize the amount of labor involved when forms are stripped or pipes are tipped out. If forms, pallets and headers are properly maintained, labor cost and better looking castings are the end result.

New forms, pallets and headers will frequently arrive with a protective coating on them to help prevent rusting in transit or until the forms are sold and delivered. In order to season these forms, the protective coating can be removed with solvents or grinding and the form release applied liberally, allowing it to set for a minimum of four hours. A 24-hour period is better, as it allows more seasoning to take place. Also, forms that are exposed to the sun will season more quickly, as higher temperatures increase the reactivity with the metal forms and rings.

Care of forms and rings

At times, you may be storing forms inside or outside for short or long periods of time. Release agents can be used to protect this vital equipment from damage. For short-term or long-term storage, a good quality VOC-compliant petroleum solvent-based form release can be used by applying a liberal coating on the form. If the forms are stored outside, even for a short period of time, a quick walk-by is often necessary to ensure that the form release has not washed off from rain. If any evidence of rust is present, apply another coat of the form release on the forms and rings as quickly as possible. A biodegradable form release is preferred, as over-application is desired and some of the material will end up on the ground.

Identifying Potential Problems

Concrete is a highly variable material because it is comprised of raw materials that potentially have a lot of variability. It is often difficult to pinpoint exactly what causes a problem because it may be a combination of a number of factors. The following are two examples of common problems often associated with excessive form release agent coverage.

• Staining has been linked to the use of excessive release agents and the use of dirty forms. Dirt, dust, rust or grease can easily be transferred from a dirty form to the finished surface of the concrete product. Once a form has been properly cleaned and coated with release agent, proper measures should be taken to minimize the potential for dust and debris to collect on the form before casting.

• Excessive bugholes occur when barrier-type release agents are applied to heavily. Barrier-type release agents tend to encapsulate free air along the vertical sidewalls, which leads to surface defects. In contrast, the metallic soap formed when using a reactive release agent allows the free air on the vertical walls to rise more easily to the surface. Proper vibration practices also reduces bugholes. The potential for bugholes and staining can be reduced by selecting an application method that produces the thinnest coat of release agent in accordance with the manufacturer’s recommendations. Release agent should not be allowed to collect and pool in the forms. Applying a thin coat, wiping up puddles and avoiding contact with reinforcing steel greatly improves the odds of producing a defect-free concrete product.

This publication is designed to provide accurate and authoritative information, however the National Precast Concrete Association does not guarantee the validity or accuracy of any data, claim or opinion appearing in this publication. If engineering, legal or other professional services are required, the services of a competent professional should be obtained. The National Precast Concrete Association does not assume and hereby disclaims liability to any person for any loss or damage caused by errors or omissions in this publication, regardless of whether such errors result from negligence, accident or any other cause whatsoever.

Read the NPCA whitepaper in its entirety.


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Tags: Concrete, Concrete Casting Products, Concrete Release Agents, National Precast Concrete Association, NPCA

Choosing and Using a Form Release Agent

Posted by Hill and Griffith Company on Aug 15, 2019 3:16:52 PM

Excerpt from the article by M.K. Hurd in the October 1996 issue of Concrete Construction

Concrete Form Release Agents Help Form Removal

Most form materials require the application of a release agent to prevent adhesion of concrete to the face of the form. Many form oils and other release agents adequately prevent sticking, but using the correct type of agent for the form material can also help to minimize concrete color variations, staining, bugholes, and poor surface durability. Article discusses the two basic types of release agents (barrier and chemically active), how to select a release agent for different form materials, and release-agent application methods. It also describes the newer types of water-based release agents, which are formulated to meet environmental regulations limiting volatile organic compounds (VOCs).

Photo caption: Forms will strip cleanly and easily if you use the correct form release agent and apply it properly. - Photo by Bob Sawyer

With the wide range of release agents available today, how do you choose the best one for your forms?

Types of Release Agents Historically, form release agents have been grouped in the following categories :
• Petroleum oils
• Emulsions—either water- or oil-based
• Nonreactive coatings with volatile solvents
• Chemically active agents
• Waxes

Though products in these categories are still available, new products and new formulations are being introduced to meet environmental regulations limiting volatile organic compounds (VOCs). Also, manufacturers may combine release-agent types, such as a chemically reactive product and an emulsion, to produce a product that has the advantages of both. Many newer form release agents, therefore, do not fit neatly into the above categories. Because environmental restrictions have caused changes in the commercially available agents, and because of the great variety of chemical formulations, manufacturers now simply classify release agents in terms of how they act instead of what’s in them. The two basic categories are barrier agents and chemically active agents. Read More.

Precautions in Selecting A Release Agent

A release agent may be incompatible with concrete that contains a number of admixtures. Compatibility problems have been reported when chemically active agents were used with concretes containing microsilica, high-range water reducers, and unusually high amounts of admixtures. Be sure to discuss possible compatibility problems with the admixture and release-agent suppliers. Read More.

Application Methods

Use enough release agent to prevent adhesion, but don’t apply too much. When overapplied, the material runs to low points in the form face where it can retard cement hydration or produce staining. Most manufacturers recommend a thin, uniform coating. With some products, the thinner the better; sometimes as little as 1 ⁄2 mil (0.0005 inch) is recommended on nonabsorbent form surfaces. Read More.

Precautions to Take During Release Agent Application

•Keep release agents off construction joints and reinforcing steel. To avoid spilling release agent on rebar, apply it before placing the steel.

• Never use release agents containing wax or silicone if the concrete surface is to be painted.

• Follow manufacturer recommendations for when to apply release agent. Some agents must dry or cure before concrete is deposited, while others can be applied only minutes ahead of concrete placement. Generally, the shorter the time between applying release agent and placing concrete, the better. Too long a wait can result in the agent drying out, running down the form face, or being washed away by the rain. (Note: Some agents are rainproof.)

• If there is any ponding or puddling of release agent, be sure to wipe away the excess material.

• After coating form faces, protect them from contamination and weather.

SELECTING A RELEASE AGENT FOR DIFFERENT FORM MATERIALS

Read the complete article in Concrete Construction Magazine


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Tags: Concrete Form Release Agents, Biodegradable Concrete Form Release, Concrete Release Agents, Concrete Forms, Concrete Form Seasoning, Concrete Casting Supplies, Concrete Voids, Concrete Form Release, Concrete Construction Magazine

Prefabricating Individual Components Within the Concrete Manufacturing Process

Posted by Hill and Griffith Company on Aug 8, 2019 6:39:04 PM

Excerpt from the article by Thomas Friedrich in the March 2019 issue of Concrete Plant International 

Screen Shot 2019-08-08 at 3.25.32 PM-1

Multifunctional construction components produced with traditional prefabrication methods need themselves to be divided up again into prefabricated modules, which are then pieced together as end products. Production work in a factory consists of assembling and connecting individual components to create an end product. The greater the number of components being installed in a concrete construction component, the greater the need to connect individual components together in advance so that they can be inserted as a unit on a ready and waiting formwork table. This defines prefabrication of components either pieced together locally in a production facility or supplied as finished components as in the automobile industry. Classic processes in a precast production facility are changing as there is an increasing demand for assembly activities. Concrete acts as a glue holding all components together. This division of labor enables product quality to be enhanced while, at the same time, accelerating production processes. Pipelines can be fastened to the reinforcement, for example. Specially created meshes can be employed in an optimum way for this purpose. Other components needing to be inserted can also be fastened to the reinforcement during installation.

Photo caption: Multifunctional concrete floors: load-bearing elements with fully integrated technical building services

The trend toward multifunctional construction components and the consequences in manufacturing

In the future, there is a growing likelihood of companies producing more than just a "concrete bed." The industry is redefining increased complexity in the shape of numerous floor components.

This requires skilled labor to achieve at a construction site.

  • For example, laying empty electrical conduits during the shell construction stage can't happen concurrently with laying pipelines.
  • Different tradesmen work on the shell during different times. 
  • This strategy requires specialized firms to organize and coordinate the work and teams

The solution for flat-shaped construction components requires manufacturing processes with large-sized framework tables. Construction happens rapidly on these tables to make the most of the large expense of building stationary units on a track or tilting table.

Prefabricated reinforcing elements

An assembly unit for reinforcement generally consists of several components, such as single bars for the span reinforcement, which is supplemented with lattice girders and stirrup cages. A steel bar mesh is employed to this end that serves as a load-bearing unit for other reinforcement elements and installed components. Read more.

Screen Shot 2019-08-08 at 3.25.41 PM-1

Photo caption: Prefabricated meshes including pipelines for room air conditioning (cooling and heating above the concrete floor).

Supplementary elements in a composite construction method (hybrid construction method)

A composite construction method is often envisaged in order to create large web plate openings. This is because secondary moments occasioned by shear load can only be absorbed with a steel structure. Read more.

Pipelines for heating and cooling with a concrete slab (modified building component activation according to the Ceiltec® principle)

Building component activation for cost-effective heating and cooling via a concrete floor is increasingly gaining in importance. Its lower temperature level is making its contribution to this trend, along with the use of renewable energy. Prefabrication is particularly useful in creating the right pipeline arrangement for the air-conditioning planned. Read more.

Entirely prefabricated load-bearing ribs as semi-finished components

Instead of prefabricated reinforcement cages for load-bearing ribs of prefabricated slabs, the rib itself can be prefabricated as a reinforced concrete construction component and then installed with starter bars on the lower slab. Read more.

Preparation on formwork tables

Some installed components are inserted directly into the underside of the floor with multifunctional floor elements. Appropriate construction components, which can be fastened directly to the formwork base are needed for this purpose. Read more.

Process in successful manufacturing

The complexity of multifunctional elements requires different processes in manufacturing. Concrete, as a material, also makes its contribution as a load-bearing element and in keeping individual construction components together. Concrete in its hardened state offers a flexible environment for installing all components. Read more.

Results with the finished product

The result with this elaborate formwork plus all its inserted components and reinforced elements is reflected in the finished product once the concrete has hardened. The appearance of the outer concrete mantle is that of a sophisticated work of art despite the high density of components, which then disappear in the concrete. Read more.

Screen Shot 2019-08-08 at 4.32.31 PM

Photo caption: Finished floor elements for large span widths on a stationary system.


Hill and Griffith Customer Service

We're known for our hands on approach. Let us visit your plant and recommend concrete release agents, packerhead concrete form releases, concrete form seasoning, potable water concrete form release, non-petroleum concrete form release, biodegradable concrete form release, rust inhibitors and concrete dissolver products that suit your needs.

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Tags: Concrete Form Release Agents, Biodegradable Concrete Form Release, Concrete Release Agents, Concrete Forms, Concrete Form Seasoning, Concrete Casting Supplies, Concrete Voids, Concrete Form Release, Concrete Plant International

Eliminate Surface Concrete Casting Bug Holes

Posted by Hill and Griffith Company on Aug 2, 2019 8:24:46 AM

 

(From Smooth On Concrete Casting Products. This is one of the best Q&A for concrete casting defects we have seen. Enjoy!

 

Concrete-Voids-1_copy.jpgHOW CAN I ELIMINATE SURFACE CONCRETE CASTING VOIDS?

Surface voids (small holes, also known as bug holes or pitting) found on the surface of concrete castings have affected anyone who has ever cast concrete. A significant number of concrete casting voids must be post finished or discarded, resulting in wasted product, time and labor. Understanding the causes of surface voids and what can be done to minimize them is the first step to a more efficient and productive casting operation.

The following information has been compiled through our (Smooth On Concrete Casting Products) experience with professionals who cast concrete for a living. Some of the tricks found here are results of many years of research and development. Although one may not find all the answers here, many of the common problems encountered when casting concrete will be addressed.

Question: What are surface voids?
Answer:
Surface voids are the cavities or little holes that appear on the surface of concrete castings. Surface voids (commonly known as pitting) are referred to as "bug holes" or "fish eyes". These voids may produce an unacceptable appearance on the surface of the finished casting.

Question: How are surface voids caused?
Answer:
Surface voids are generally attributed to the following three factors: release agent, water or air (sometimes a combination of the three).

Concrete-Voids-2_copy.jpgQuestion: How does a release agent affect the surface of a concrete casting?
Answer:
Release agents act as a "lubricant" between the mold and the concrete itself. The proper application of a release agent will yield castings without surface voids. However, when a release agent is over applied, it may "pool" or "puddle" on the lower extremities of the mold. As the concrete is poured into the mold these pools prevent the concrete from filling in all the detail. When the casting is removed from the mold voids will be apparent in the areas where pooling occurred. Vibration magnifies this problem by forcing additional release agent into the lower extremities of the mold. Voids caused by too much release agent are recognizable as small spherical voids on the surface
of the finished casting. These voids usually measure about 1/8" (.31 cm).

Question: How does water cause surface voids?
Answer:
Similar to release agents, water is also trapped against the mold's working surface resulting in voids. As the concrete cures and the residual water evaporates, a cavity is left behind on the surface of the casting. Vibration also tends to force water from the cementious material, however most voids caused by water are a result of a high water to cement ratio. Similar to release agents, water is also trapped against the mold's working surface resulting in voids. As the concrete cures and the residual water evaporates, a cavity is left behind on the surface of the casting. Vibration also tends to force water from the cementious material, however most voids caused by water are a result of a high water to cement ratio.

Question: How does air cause surface voids on my finished concrete casting?
Answer:
In most circumstances, air voids have an irregular shape and tend to be much larger (1/2" or 1.27 cm.) than those caused by water or release agents. The air voids are caused by air trapped between the mold surface and the concrete. They generally appear in low slump concrete and can be found underneath irregular (non-spherical) shaped pieces of crushed aggregate.
This is a result of having too little mortar to fill the spaces around the aggregate. Voids caused by air may also be found in castings that have severe undercuts.


HOW TO ELIMINATE VOIDS IN A CONCRETE CASTING:

While many variables must be considered in the elimination of surface voids or bug holes in concrete castings, there are a number of precautions that can remedy this unsightly problem.

Careful preparation and methodical practices can eliminate even the worst of surface voids. The following section describes procedures and materials that will produce finished castings that even the most discerning eye will accept.

Question: Will adding more mortar to the concrete assist in reducing surface voids?
Answer:
Yes. Increasing the amount of mortar in the cementious material will help make the material more fluid. A mixture that has a higher mortar content will assist in encapsulation of the aggregate. By encapsulating the aggregate, mortar also provides a chimney or venting system that will allow air and water bubbles to escape from the mixture. During vibration these bubbles will rise through the mortar and escape through the opening of your mold. A higher mortar content in your mixture also allows larger pieces of aggregate to easily move during vibration and thereby release any air that may have been trapped.

Question: What will happen to my casting if I use a larger aggregate?
Answer:
Using a larger aggregate may cause more surface voids because air is entrapped under the irregular shapes of this material. There is also a larger volume of voids between larger aggregate pieces than smaller pieces. It is therefore recommended that a smaller aggregate be used or that a smaller aggregate be mixed with the larger particles. The smaller aggregate will act as a "roller system" to assist in turning the larger pieces of aggregate during vibration. It is recommended to use aggregate that passes through a number 50, 100 or 200 sieve.

Question: Does the type of cement I use in my mixture make a difference?
Answer:
Cement acts as a lubricant during vibration and allows larger pieces of aggregate to move around freely. Therefore it is recommended that a very fine cement be used to achieve a more fluid consistency. Fly ash, which is finer than cement particles, will increase the lubricity of the cement even further.

Question: What precautions should I take if my concrete has a low water-cement ratio?
Answer:
If the concrete you are casting has a low water-cement ratio, more mixing time will ensure that water and air bubbles are forced away from the aggregate and thereby eliminate the voids on the casting surface. Low water-cement ratio concrete also requires an increased vibration period.

Question: I've heard that adding plasticizers to my concrete mixture will help eliminate surface voids. Is this true?
Answer:
Yes. The addition of plasticizers are used effectively in creating large slump increases. The benefit of using a plasticizer is that these large increases can be attained without effecting the water-cement ratio. The result of increasing the slump will assist air, water and aggregate to move more freely throughout the mixture. Although plasticizers will permit a large increase in slump, the concrete will begin to set much quicker. This means that there is a much smaller time period for the concrete to be vibrated. In order to eliminate surface voids from appearing we recommend using a release agent in tandem with plasticizers. The release agent will allow the concrete to move freely and force voids away from the surface of the casting

Question: What type of mold or form material should I use?
Answer:
Form or mold surfaces be as smooth as possible to decrease the surface tension between the concrete and the mold. Rubber molds are being used more and more for just this reason. The proper release used on a rubber mold will give the best possible surface.

Question: I'm vibrating the concrete, but still have bug holes in the casting?
Answer:
This occurs because air and water bubbles are the lightest elements of the concrete and will naturally flow to the most fluid portion of the mix. It just happens that this area is next to vibrator. So if you are using an external vibrator, the form or mold should be hammered. Hammering allows the mortar to flow toward the area being hit, consequently pushing air and water bubbles to the opening of your mold. This technique is recommended for molds with deep undercuts, where air and water bubbles tend to be predominate.

Question: How beneficial are release agents?
Answer:
Not only do release agents assist in eliminating surface voids, they also prolong the life of your mold. However, choosing the correct release agent and proper application are extremely critical. Various release agents will provide different surface finishes of your concrete casting. We recommend a chemically active release agent.

The amount of release that is applied to the mold or form will greatly effect the surface of your casting. Excess release agent tends to consolidate into spheres that cause bug holes. Too much release agent can be evidenced by voids on the lower portions of your casting. Applying release agent in a thin coat will eliminate these voids.



HELPFUL HINTS TO VOID FREE CASTING:
As any professional caster will tell you casting concrete is not an exact science. There are many variables and therefore no way to ensure void free castings. Voids can be minimized, however, and the following hints are offered to improve your chances for success.

Hint # 1
Extend the mix time to help break up any residual air or water bubbles. This will promote a more uniform and workable consistency.

Hint # 2
Make sure to that release agents are applied in thin films. This will eliminated any pooling or puddling in the lower portions of your mold.

Hint # 3
Lower the viscosity of cement by adding sand or fly ash. This allows large aggregate to move more freely and reduces the amount of air entrapment.

Hint # 4
Use aggregate that is more uniform in shape. Irregular shaped pieces of aggregate tend to make the concrete less fluid.

Hint # 5
Techniques used during vibration can eliminate most surface voids. Vibrating both the outside and inside of your mold will draw most air and water bubbles away from the surface of the concrete. Hammering the mold can eliminate any residual voids.

Disclaimer
This FAQ article is offered as a guideline and offers possible solutions to problems encountered during mold making and casting. No warranty is implied and it is up to the end user to determine suitability for any specific application. Always refer to the provided Technical Bulletins (TB) & Safety Data Sheets (SDS) before using any material. A small scale test is suggested to determine suitability of any recommendation before trying on a larger scale for any application.


Hill and Griffith Customer Service

We're known for our hands on approach. Let us visit your plant and recommend concrete release agents, packerhead concrete form releases, concrete form seasoning, potable water concrete form release, non-petroleum concrete form release, biodegradable concrete form release, rust inhibitors and concrete dissolver products that suit your needs.

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Bulletins and Technical Papers for Concrete Casting Products

 

Tags: Concrete Form Release Agents, Biodegradable Concrete Form Release, Concrete Release Agents, Concrete Forms, Concrete Form Seasoning, Concrete Casting Supplies, Concrete Voids, Concrete Form Release, Bug Holes

Precast Concrete Form Release Agent Q&A from ACI

Posted by Hill and Griffith Company on Jul 25, 2019 8:00:00 AM

Technical Questions - Precast Concrete Form Release Agent 

American Concrete Institute

Q. I need to select a precast concrete form release agent for a new project requiring an architectural finish. Can you provide information on different types of form release agents and recommendations for using them? Does ACI have a publication on form release agents I could use as a reference?

A. Form release agents ease formwork removal, extending the useful life of a form and improving the smoothness and texture of concrete surfaces. Two main types are available: barrier and chemically active.

Barrier-type agents (examples include diesel oil, wax, and silicone) create a barrier between the form and the concrete. These are not recommended for architectural concrete, because they can cause stains, surface air voids, and problems with form removal in very cold or very hot weather; they also may prevent subsequent adhesion of coatings to the hardened concrete. While diesel oil was once commonly used, it’s now prohibited because the associated volatile organic content (VOC) emissions contribute to smog. (Note: In the United States, form release agents have to meet federal VOC limits of 450 g/L [3.8 lb/gal.] and may have to meet more restrictive limits of 250 g/L [2.2 lb/gal.] in some states.)

Chemically active form release agents (certain types of fatty acids) react with calcium ions in the cement paste to produce a soap that prevents concrete from bonding to the formwork. Based on the reactivity, they are divided into buffered (partially) reactive and fully reactive. Buffered agents produce an improved soap film that helps remove entrapped air and may promote better flow of a thin skin of cement paste at the surface of the form. Fully reactive agents can provide a good basic soap film that, depending on the brand, works well in most cases. Because chemically active form release agents produce fewer bugholes, stains, and surface irregularities than barrier type of form release agents, they are commonly used for architectural concrete.

For more information on this topic refer to ACI 347R “Guide to Formwork for Concrete”, ACI 303R “303R-12 Guide to Cast-in-Place Architectural Concrete Practice”, and ACI 533R “Guide for Precast Concrete Wall Panels”.


Precast Concrete News from the American Concrete Institute

ACI and the Greater Miami Valley Chapter – ACI Convention this fall Cincinnati, OH, October 20-24

Seminar – ACI 318-19: Changes to the Concrete Design Standard

ACI Foundation is Now Accepting Fellowship and Scholarship Applications


Hill and Griffith Customer Service

We're known for our hands on approach. Let us visit your plant and recommend concrete release agents, packerhead concrete form releases, concrete form seasoning, potable water concrete form release, non-petroleum concrete form release, biodegradable concrete form release, rust inhibitors and concrete dissolver products that suit your needs.

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 Bulletins and Technical Papers for Concrete Casting Products

Tags: Concrete Casting Products, Concrete Release Agents, Concrete Casting Supplies, Precast Concrete, ACI

Article Review: Concrete Formed Surface Classifications & Specifications

Posted by Hill and Griffith Company on Jul 18, 2019 1:06:30 PM

Details on classifications & specifications for surface finishes

An excerpt from the July/August 2019 issue of Precast Inc., by Eric Carleton, P.E., NPCA's director of codes and standards.

Evaluating_and_Diagnosing_Concrete_Formed_Surface_Imperfections

Less is better when spraying concrete form release agents on concrete forms.

In 1975, the International Council for Building Research established a general classification of formed surfaces which is referenced in the most recent edition of ACI 301.2R, "Identification and Control of Visible Effects of Consolidation on Formed Concrete Surfaces."

Those classifications are:

  1. Rough - No special requirements for finishing
  2. Ordinary - surface finishing has a minor factor
  3. Elaborate - definite requirements for visual appearance
  4. Special - highest standards for appearance [considered architectural]

Within ACI 347R-14, "Guide to Formwork for Concrete," there is a similar class system to differentiate concrete surface evaluation based on application:

  1. Class D - minimum quality requirement for surfaces where roughness is not objectionable, usually applied where surfaces will be permanently concealed.
  2. Class C - general standard for permanently exposed surfaces where other finishes are not specified
  3. Class B - intended for coarse-textured, concrete form surfaces intended to receive plaster, stucco or wainscoting
  4. Class A - suggested for surfaces prominently exposed to public view where appearance is of special importance

ACI 301-16, "Specifications for Structural Concrete," provides more detailed information.

5.3.3.3(a) Surface finish-1.0 (SF-1.0):

  • No formwork facing material is specified
  • Patch voids larger than 1-1/2-inch wide or 1/2-inch deep
  • Remove projections larger than 1 inch
  • Tie holes need not be patched
  • Surface tolerance Class D as specified in ACI 117-10, "Specification for Tolerances for Concrete Construction and Materials and Commentary."
  • Mockup not required

5.3.3.3(b) Surface finish-2.0 (SF-2.0):

  • Patch voids larger than 3/4-inch wide or 1/2-inch deep
  • Remove projections larger than 1/4 inch
  • Patch Tie holes
  • Surface tolerance Class B as specified in ACI 117
  • Unless otherwise specified, provide mockup of concrete surface appearance and texture

5.3.3.3(c) Surface finish-3.0 (SF-3.0):

  • Patch voids larger than 3/4-inch wide or 1/2-inch deep
  • Remove projections larger than 1/8 inch
  • Patch Tie holes
  • Surface tolerance Class A as specified in ACI 117
  • Provide mockup of concrete surface appearance and texture

5.3.3.5 Unspecified as - cast-finishes - if a surface finish is not specified, provide the following finishes:

  • SF-1.0 on concrete surfaces not exposed to view
  • SF-2.0 on concrete surfaces exposed to view

For the full article, please visit the Precast.org site.


Hill and Griffith Customer Service

We're known for our hands on approach. Let us visit your plant and recommend concrete release agents, packerhead concrete form releases, concrete form seasoning, potable water concrete form release, non-petroleum concrete form release, biodegradable concrete form release, rust inhibitors and concrete dissolver products that suit your needs.

Hill and Griffith Samples

Product Samples

We are pleased to provide samples in quantities large enough to allow you to "try before you buy."
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Hill and Griffith Customer Service

Technical Services & Support

On-site casting defect investigations, product testing, machine start-ups and much more. Also, lab facilities are available to provide testing upon request.
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 Bulletins and Technical Papers for Concrete Casting Products

Tags: Concrete Casting Products, Concrete Release Agents, Concrete Casting Supplies, Precast Concrete, Gricote, Precast Inc Magazine

Article Review: Evaluating and Diagnosing Formed Surface Imperfections

Posted by Hill and Griffith Company on Jul 11, 2019 4:18:57 PM

Precast formed concrete surface problems and how to identify and correct them

An excerpt from of the article found in the July/August 2019 issue of Precast Inc., by Eric Carleton, P.E., NPCA's director of codes and standards.

Evaluating_and_Diagnosing_Concrete_Formed_Surface_Imperfections

Less is better when spraying concrete form release agents on concrete forms.

Green Bay Packers Coach Vince Lombardi said, “Perfection is not attainable, but if we chase perfection, we can catch excellence.” Precast manufacturers try to make perfect products, but like most things, attaining complete perfection is elusive if not impossible. While the goal is to attain perfection, precasters recognize the economic and production realities that some product irregularities will occur. The goal is to mitigate imperfections while still maintaining tolerances and meeting owners’ expectations.

For (precast) formed concrete surfaces, many problems can be narrowed down to three practices: consolidation or vibration, form set up and maintenance, and form oil/release agent application.

Common issues:

  1. Bugholes
    1. Poor or improper concrete consolidation
    2. Excessive application of form release oil or agent
  2. Honeycombing
  3. Cracking
  4. Fins
  5. Form Bleed
  6. Poor Form Fit
  7. Sand Streaking
  8. Layering Marks
  9. Cold Joint
  10. Staining
  11. Color Continuity

Regardless of the end use, a well-cast product, free of formed surface irregularities, provides an excellent representation of a quality operation.

For the full article, please visit the Precast.org site.


Hill and Griffith Customer Service

We're known for our hands on approach. Let us visit your plant and recommend concrete release agents, packerhead concrete form releases, concrete form seasoning, potable water concrete form release, non-petroleum concrete form release, biodegradable concrete form release, rust inhibitors and concrete dissolver products that suit your needs.

Hill and Griffith Samples

Product Samples

We are pleased to provide samples in quantities large enough to allow you to "try before you buy."
Contact Us »

 

Hill and Griffith Customer Service

Technical Services & Support

On-site casting defect investigations, product testing, machine start-ups and much more. Also, lab facilities are available to provide testing upon request.
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 Bulletins and Technical Papers for Concrete Casting Products

Tags: Concrete Casting Products, Concrete Release Agents, Concrete Casting Supplies, Precast Concrete, Gricote, Precast Inc Magazine

Employees drive safety and product quality in American precast concrete pipe plants

Posted by Hill and Griffith Company on Jul 5, 2019 3:25:38 PM

Producer members of the American Concrete Pipe Associa­tion empower their employees to introduce new ways to elevate the safety of workspaces and improve product quality.

As published in the March 2019 issue of CONCRETE PLANT INTERNATIONAL, by Russell Tripp, P.E., President, American Concrete Pipe Association, USA

Qualtity Precast Concrete Pipe 2

The O-ring guard developed by Forterra Pipe and Precast (Lorena Texas Plant) improves control when installing or removing O-rings following production

Each year, employees and their companies are celebrated at the ACPA's Pipe School/Pipe Show with safety and quality awards. At the 2019 Pipe School/Pipe Show, top awards were presented for a clip gun guard; O-ring snap band guard/remover; visual job task analysis; batch plant operator training, product tags, and a lift hole spreader. The Chairman's Safety Award recognizes plants and/or companies that have implemented successful safety initiatives that result in a safer and more productive workplace. The Chairman's Quality Award recognizes member plants and/or com­panies that have implemented successful innovations result­ing in higher quality products and more efficient production processes. 

Chairman's Safety Award - Company-Wide
Winner of the 2018 Chairman's Safety award was Rinker Materials - Dallas, TX for the Clip Gun Guard. The guard devel­oped after several employee's received injuries to hands and fingers when using the tool. Development of the guard in­cluded the manufacturer of the clip gun and plant personnel. The Clip Gun Guard is now used at all Rinker Facilities and a safety feature for the manufacturer.

Chairman's Safety Award - Equipment-Related - O-Ring Guard
O-ring snap bands, that can be very large in diameter, are no­torious for their uncontrolled springing action. When they are removed, they are awkward and can spring in many direc­tions. The O-ring guard developed by Forterra Pipe and Pre­cast (Lorena Texas Plant) improves control when installing or removing O-rings following production.

Chairman's Safety Award - Individual Facility - Visual Job Task Analysis (JTA)
JTA is a very difficult system to incorporate in heavy manufac­turing. There are many activities occurring simultaneously. The visual JTA introduced by Rinker Materials - Pipe Division (Cor­porate) uses a tablet to allow leaders to easily access video of safe processes in the work area and provide training to new or transferred employees. Documenting training for Job Task Analysis is digital and accessible.

Qualtity Precast Concrete Pipe 3

The Clip Gun Guard was developed after several employees received injuries to hands and fingers when using the tool.

Chairman's Quality Award - Company-Wide Best Practice - Batch Plant Operator Training
Production of high-quality products begin with batch plant operators. The company-wide quality goal of Rinker Materials - Pipe Division (Corporate) is to achieve a "Batch Plant Oper­ator Training Certificate." Training provides further under­standing of the batching system features. Batch Plant Training also serves to train backup operator(s) at each plant who pos­sess a much stronger understanding of the control system and "concrete science."

Chairman's Quality Award - Company-Innovation (Product Tags)
Northern Concrete Pipe, Inc. was looking for a way to ensure that cages produced in advance of production would be used for the correct project and/or product. The company wanted to be certain that any reinforcing that is unique is easily iden­tifiable, and to ensure that no reinforcement cages would be placed into production before inspection and release by qual­ity control personnel.

Product tags are now fastened to pre-assembled reinforcing cages and color coded when reinforcing is unique, such as, when a cage has a block out, anchors, no spigot, or is pro­duced to a specific lay length. The information on the tags en­sures that when reinforcing cages are produced for similar projects or products, the reinforcing will not get mixed. Ac­countability and the ability to track repeat mistakes and pro­vide training is assured when the person that assembled the reinforcing signs the ticket. Tags eliminate cages from being placed into production without pre-pour inspection. Color coding makes everyone aware that reinforcing is unique and what is unique about it.

Chairman's Quality Award - Individual Plant Process Improvement - Lift Hole Spreader
Lift holes in heavily reinforced products are challenging to place. Northern Concrete Pipe, Inc. does not allow the use of torches on cages and wanted a better way to keep cages specified without sacrificing safety or increasing employee ex­ertion. The lift hole spreader accurately places lift hole openings in reinforcement cages and eliminates wire showing in lift holes while reducing worker stress. By eliminating exposed wire in lift holes, contractors use their lifting apparatus correctly and efficiently. This innovation reduces the chance for leakage around exposed wires to penetrate the wall of the product.

QCast Plant Certification Program
Both the safety and quality awards are reinforced by the ACPA's QCast Plant Certification Program, which is the recog­nized standard for quality assurance in America's concrete pipe industry. Plants may be certified in storm sewer and cul­vert pipe, sanitary sewer, box culverts, three-sided structures, manholes, and precast structures.

Qualtity Precast Concrete Pipe 1


QCast is a voluntary program to continue the advancement of quality in the precast concrete pipe and products industry. Each year the manual for the program is reviewed and when necessary updated to accommodate industry-wide standards revisions, and changes in production technology. The manual requires that management ensure that the supervisory and production personnel immediately responsible for product quality are properly trained. The training results in innovation in safety and quality that is recognized industry-wide.

The safety and quality awards, and the QCast program are el­ements of the ACPA's Quality School held each year at the be­ginning of the heavy production season. The 4-day school is attended by veteran employees and new hires alike. Employ­ers encourage their production staff to attend and return to their workplaces with certificates attesting to their compe­tence in modern production techniques, reinforcement, con­crete mixing, batching and transport, self-consolidating con­crete, consolidation, pre and post-pour inspection, curing and fundamental calculations.

The high quality of concrete pipe and the production facilities of member companies are represented by ACPA's safety and quality awards, QCast certification program and Quality School. But it is the friendly competition between members for the awards, and then sharing the knowledge associated with the entries that result in safe workplaces and greater ef­ficiencies in production. There is no doubt that the Chairman's Safety Award and Chairman's Quality Award drive innovation that is characteristic of the concrete pipe plants of ACPA's pro­ducer members.

American Concrete Pipe Association
8445 Freeport Parkway, Suite 350, Irving, Texas 75063-2595, USA T +1 972-506-7216, F +1 972-506-7682
info@concretepipe.org
rtripp@concretepipe.org
www.concretepipe.org


Hill and Griffith Customer Service

We're known for our hands on approach. Let us visit your plant and recommend concrete release agents, packerhead concrete form releases, concrete form seasoning, potable water concrete form release, non-petroleum concrete form release, biodegradable concrete form release, rust inhibitors and concrete dissolver products that suit your needs.

Hill and Griffith Samples

Product Samples

We are pleased to provide samples in quantities large enough to allow you to "try before you buy."
Contact Us »

 

Hill and Griffith Customer Service

Technical Services & Support

On-site casting defect investigations, product testing, machine start-ups and much more. Also, lab facilities are available to provide testing upon request.
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 Bulletins and Technical Papers for Concrete Casting Products

Tags: Concrete Casting Products, Concrete Release Agents, Concrete Casting Supplies, Precast Concrete, Gricote, Concrete Plant International Magazine

More is Better in Baseball - Less Release Agent is Better in Precast Concrete

Posted by Hill and Griffith Company on Jun 28, 2019 5:27:07 PM

The Perfect Release with Grifcote concrete form release agents that are readily and inherently biodegradable.

Less is better with Precast Concrete From Release 4

Grifcote® products are the most widely used concrete form release agents in the United States, Canada and Puerto Rico.

All release agents are easily sprayed, swabbed or wiped.

More Beer is Better - Less Release Agent is Better with Precast Concrete

Less is better with Precast Concrete From Release 3

Gifcote products are non-staining and ready to use with no mixing needed and offer many unique features to improve concrete separation from forms, pallets and molds.

Grifcote carries a non-flammable/noncombustible rating and is considered DOT hazardous material exempt. Drivers DO NOT need to be HM 126 or use placards. We’ve engineered Grifcote products to have low odor and flash points above 260 degrees Fahrenheit to keep workers safe.

Grifcote is chemically formulated to help reduce the formation of bug holes. Reactive fatty acid/methyl esters react with free lime. The reactive ingredients in Grifcote creates a metallic soap that eases separation from the form.

All products comply with all federal or state regulations regarding concrete release agents.

More Speed is Better on the Lake - Less is Better in Precast Concrete Release Agent

Less is better with Precast Concrete From Release 1

And are classified as either readily biodegradable, with a half-life of 28 days or less or inherently bio-degradable with a half-life of 60 days or less.

Grifcote is EPA VOC compliant. With less than 250 grams per liter of Volatile Organic Compounds Grifcote is compliant in all 50 States and Canada.

Spraying form release agents on mixers and equip-ment reduces labor and cleanup at the end of the day eliminating concrete adhering to the equipment.

Coverage rates are determined by the person applying the material and the low viscosity of Grifcote. In all cases, the “Thinner is better” concept applies for maximum coverage and best release and finish.

You can purchase Grifcote products in drums, 300-gallon totes or bulk tanks. Grifcote has indefinite freeze/thaw cycles. You don’t need to worry about Grifcote degradation due to temperature changes.

FR-50-VOC is the work horse for the concrete industry.

More Speed is Better in Racing - Less is Better in Precast Concrete Release Agent Application

Less is better with Precast Concrete From Release 2

Grifcote form release agents are designed for specific industry applications including: precast, pipe, burial vault, prestressed and other similar applications.

PR-SS-VOC is designed for Packerhead pipe operations and those really tough release jobs. Give us your toughest release challenge and we’ll recommend an economical solution. 

CC-150-VOC is used to season concrete forms for the best release.

The Hill and Griffith Company works closely with pipe and form equipment manufactures to provide optimum release characteristics.

LV-50 Plus was created specifically for use with potable water and for seasoning forms. It is NSF (ANSI 61) approved for use with potable water with some restrictions in specific applications.

 

Happy Fourth of July week!


Hill and Griffith Customer Service

We're known for our hands on approach. Let us visit your plant and recommend concrete release agents, packerhead concrete form releases, concrete form seasoning, potable water concrete form release, non-petroleum concrete form release, biodegradable concrete form release, rust inhibitors and concrete dissolver products that suit your needs.

Hill and Griffith Samples

Product Samples

We are pleased to provide samples in quantities large enough to allow you to "try before you buy."
Contact Us »

 

Hill and Griffith Customer Service

Technical Services & Support

On-site casting defect investigations, product testing, machine start-ups and much more. Also, lab facilities are available to provide testing upon request.
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 Bulletins and Technical Papers for Concrete Casting Products

Tags: Concrete Casting Products, Concrete Release Agents, Concrete Casting Supplies, Precast Concrete, Gricote

The Hill and Griffith Company Welcomes Executive-Level Director of Sales

Posted by Hill and Griffith Company on Jun 17, 2019 2:58:41 PM

The Hill and Griffith Company is proud to announce and welcome Ryan Canfield as the company’s Director of Sales & Business Development.

Ryan Canfield 560

Ryan will be responsible for sales team leadership, driving revenue, contributing to product selection, marketing, as well as general management responsibilities.

Canfield also comes to H&G with 17+ years of experience in sales, technical support, marketing and engineering for the foundry, die cast, precast and prestress concrete industries. Ryan’s proven track record was instrumental in increasing annual company revenue, customer retention and customer satisfaction ratings in previous direct sales and management roles. He also holds an Engineering Degree from Trine University in Angola, IN.

He joins the H&G team from Carbo Ceramics located in Houston, TX.

#marketing #sales #concrete


Hill and Griffith Customer Service

We're known for our hands on approach. Let us visit your plant and recommend concrete release agents, packerhead concrete form releases, concrete form seasoning, potable water concrete form release, non-petroleum concrete form release, biodegradable concrete form release, rust inhibitors and concrete dissolver products that suit your needs.

Hill and Griffith Samples

Product Samples

We are pleased to provide samples in quantities large enough to allow you to "try before you buy."
Contact Us »

 

Hill and Griffith Customer Service

Technical Services & Support

On-site casting defect investigations, product testing, machine start-ups and much more. Also, lab facilities are available to provide testing upon request.
Contact Us »

 

 Bulletins and Technical Papers for Concrete Casting Products

Tags: Concrete Form Release Agents, Concrete Release Agents, Ryan Canfield

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