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Concrete Casting News from the Hill and Griffith Company

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


Additional News from Concrete Construction Magazine

Tilt-Up Innovations

Three Key Lessons About Moisture in 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.

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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 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.

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 »

 

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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 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.

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

A Short History of Concrete Pipe by the PCA

Posted by Hill and Griffith Company on Feb 14, 2019 9:00:29 AM

Concrete pipe has a well established history and reputation for being a long lasting, serviceable material.

Concrete-Form-Release-Agent-1.jpgThe Cloacae Maxima, built in about 180 B.C. as part of Rome's main sewer system, was constructed mainly of stone masonry and natural cement concrete. More than 2,000 years later, portions of the concrete sewer are still in use.

Modern day concrete sewer systems emerged during the mid-19th century when the public became conscious of the need for sanitation to control the spread of disease. The earliest recorded use of concrete pipe in the United States is a sewer installation built in 1842 at Mohawk, N.Y. Other New England cities followed suit and installed concrete pipelines in the second half of the nineteenth century. Many of these concrete pipelines are still in use today.

Milestones in development include the production of the first reinforced pipe in 1905, the invention of prestressed pipe in the 1930s, and the manufacture of the first steel-cylinder prestressed pipe in 1942. 

Sizes can range from four inches up to 17 feet in diameter. Although pipe can be manufactured in a variety of shapes, there are five standard shapes: circular, horizontal elliptical, vertical elliptical, arch, and rectangular. The pipe shape selected for a project depends on the topography of the site, importance of hydraulic and structural efficiency, erosion and deposition in the stream channel, and cost. Most often, the preferred pipe shape is the one that will alter the natural drainage flow the least.

Concrete-Form-Release-Agent-2.jpgFive Methods of Producing Pipe Made of Concrete

As with all concrete products, the basic materials are portland cement, aggregate, and water. There are five basic methods of producing pipe. Four methods -- centrifugal/spinning, dry cast, packerhead, and tamp-entail using a dry concrete mix. The fifth method, wet casting, uses a high-slump concrete mix. Wet-cast concrete mix usually has a slump less than four inches and is most frequently used for manufacturing large diameter pipe.

These types of pipe serve as a conduit material for irrigation, water supply lines, sanitary sewers, culverts, and storm drains. Culverts, usually made with arch-shaped concrete, are used to carry water under highways in non-urban areas. Storm drain systems for cities and towns are becoming more important as communities become larger and more densely populated. Recent major floods and the resulting damage only emphasize the need for efficient drainage systems.

Subsurface drainage carries away water below the surface of the pavement. This water reduces flow support capacity of the base and subgrade material causing potential damage to roads, airport runways, and building foundations. Many farm fields depend on proper underground drainage for their cultivation. Thousands of square miles of otherwise arid land rely on concrete irrigation pipe to supply water for farmland. Additionally, most of the large cities in the United States a pipe system made of concrete to transport their water supply.

(From the Portland Cement Association's web site.The PCA is a powerful and vocal advocate for sustainability, jobs creation, economic growth, infrastructure investment, and overall innovation and excellence in construction throughout the U.S.)

More information at the American Concrete Pipe Association web 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.
Contact Us »

 

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 Pipe, Concrete Form Release, Portland Cement Assoc

New Benefits for NPCA Certified Plants Coming Soon. What is Biodegradable Form Release?

Posted by Hill and Griffith Company on Apr 27, 2018 1:07:10 PM

The Producer Portal

The National Precast Concrete Association Quality Assurance Committee announced improvements to the NPCA Plant Certification program that will make it easier than ever to organize and save your production documents. Available for certified plants, this free member service is located in the plant documents section of the Producer Portal.

The new section matches the table of contents of the NPCA Quality Control Manual for Precast Concrete Plants, making it easy to organize and store the current and historical quality-related documents that are required by the plant certification program. The portal is secure and confidential. The only people who can see the documents are designated plant employees, NPCA program administrators and the plant certification auditor. This enhancement enables plants to upload and organize documents specific to each chapter, section and subsection of the manual.

Log in to the Producer Portal at precast.org/certification and choose Plant Documents from the menu on the left side of the screen to explore the options. To access historical data, simply choose Archived Documents from the drop-down list at the top of the page. To navigate between sections, use the “jump to” feature.

For more information or help logging in, contact Andi Pierce.

NPCA Offers New Water and Wastewater Tank Product Certification

If you manufacture precast concrete tanks, NPCA’s new ANSI-accredited product listing will take the certification of your tanks to a new level. ANSI has granted NPCA a program scope extension of the Plant Certification program to offer the product-specific listing exclusively for water and wastewater tanks.

By obtaining a product listing for your tank models, you give specifiers the assurance that your products are designed and manufactured to applicable industry standards and ensure you are able to supply products in areas where a listing is required. While plants interested in participating must be NPCA certified, there is no additional cost to be listed. This optional program goes beyond plant processes with additional criteria such as a watertightness test of a randomly selected tank. In addition, tanks models listed will appear on the NPCA website during member searches so specifiers can see which models are listed by your plant.

Plants opting for product certification must submit a complete package of information based on the most current applicable ASTM and industry standards. The detailed submittal covers criteria such as materials and manufacture, structural design, physical design, quality control, performance testing data, and dimensional details including tolerance and product marking. For more information, contact Phillip Cutler, P.E., NPCA’s Director of Quality Assurance Programs.


What-is-biodegradable-form-release-agent-report

What is Biodegradable Form Release Agent?

One definition of “biodegradability” can be found in the EPA 1998, “Fate, Transport and Transportation Test Guidelines, Office of Prevention, Pesticides and Toxic Substances (OPPTS) 835.3100, Aerobic Aquatic Biodegradation”; and in EPA 712-C-98-O and ASTM D-5864-00, “Standard Test Methods for Determining Aerobic Aquatic Biodegradation of Lubricants or Their Components.” This reference gives everyone the guidelines to be followed when determining biodegradability and using the word “biodegradable” in claims relating to various products, including concrete form release agents. The U.S. EPA definition includes an allowable “28-day half-life” of materials in order to be considered biodegradable. Half-life is the time required for the decay of one-half of a given component in a system.


Precast Concrete in the Google News Feed:

The precast concrete market is projected to grow at a CAGR of 5.96%

Architect and Builder Agree: Precast Concrete Foundations Ideal Start for Affordable Housing Project


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 and non-petroleum concrete form release, biodegradable releases, 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: Biodegradable Concrete Form Release, Concrete Casting Supplies, Concrete Form Oil, Concrete Form Release, Concrete Form Release Agent, Form Release

Readily & Inherently Biodegradable Concrete Form Release Agents

Posted by Hill and Griffith Company on Jun 22, 2017 3:11:13 PM

Hill & Griffith offers the perfect release with Grifcote concrete form release agents that are readily and inherently biodegradable.

Grifcote® products, the most widely used concrete form release agents in the United States, Canada and Puerto Rico, offer many unique features to improve concrete separation from forms and molds.

Biodegradable Concrete Form Release Agents 1 copy.jpg

Forms and molds are not stained by Grifcote products. Gricote is ready to use with no mixing needed. All release agents are easily sprayed, swabbed or wiped. Since worker safety is vital to your operations, we’ve engineered Grifcote products to have low odor and flash points above 200 degrees Fahrenheit to keep workers safe. Grifcote carries a non-flammable/non-combustible rating.

Biodegradable Concrete Form Release Agents 2 copy.jpg

Grifcote Products are not considered a DOT hazardous material and are exempt from placards. Drivers DO NOT need to be Haz Mat 126 Certified to transport)

Biodegradable Concrete Form Release Agents 3 copy.jpg

In addition, Grifcote is chemically formulated to reduce the formation of bug holes. Reactive fatty acid/methyl esters react with cement. The metallic soap that is formed eases separation from the form and minimizes sticking. The high viscosity allows Grifcote to be easily spread over large spans. Coverage rates are determined by the person applying the material. In all cases, the “Thinner is better” rule applies for maximum coverage and best release and finish.

Other uses of Grifcote include assisting form and pallet cleanup. Spraying form release agents on mixers and equipment also speeds cleanup at the end of the day. Plus all EPA VOC and OSHA requirements are met by Grifcote products.

Biodegradable Concrete Form Release Agents 6 copy.jpg

With indefinite freeze/thaw cycles or teeter cycles, you don’t need to worry about Grifcote degrading due to temperature changes. So, you can purchase Grifcote products in 6,000-gallon tanks or as small as 5-gallon pails depending on your needs.

Biodegradable Concrete Form Release Agents 7 copy.jpg

Grifcote form release agents are designed for specific industry applications. For example, FR-50-VOC/R-VOC are used for precast, pipe, burial vault, prestressed and other similar applications.

While the PR-SS-VOC would work best for Packerhead pipe operations and those really tough release jobs.

Biodegradable Concrete Form Release Agents 8 copy.jpg

Other specific products were created specifically for use with potable water and for seasoning forms. The LV-50 Plus is NSF (ANSI 61) approved for use with potable water (some restrictions may apply).

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

Biodegradable Concrete Form Release Agents 9 copy.jpg

Our products have low VOC and are non-carcinogenic according to the ACGIH, NTP, IRAC or OSHA.

Biodegradable Concrete Form Release Agents 4 copy.jpg

All Grifcote products are readily biodegradable, which means they have a half-life of 28 days or fewer. And by definition, all Grifcote products are inherently biodegradable with a half-life of 60 days or fewer.

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: Biodegradable Concrete Form Release, Concrete Casting Products, Concrete Release Agents, Concrete Casting Supplies, Grifcote FR 50 Concrete Form Release, Grifcote, Precast Concrete Form Release, Concrete Form Release Application

Precast Wall Concrete Form Release Application Video

Posted by Hill and Griffith Company on Aug 25, 2016 10:33:02 AM

(We love "How It's Made" and this episode shows how precast concrete walls are made and includes video of the application of release agent.)

Concrete-Form-Release-Application-Video.jpgPublished on May 14, 2015 by the Science Channel.

"A mix of limestone gravel, minerals and additives are mixed into a slurry. After a test sample is hardened and tested, workers pour it into pre-made molds."

 Here's a list of the sections of the video:

  • Concrete mixing

  • Form set up

  • Foam letter placement for imprint on wall

  • Form release application

  • Steel cable placement and pre-tensioning

  • Rebar placement

  • Wire mesh placement

  • Pour first layer of concrete

  • Place second set of rebar and mesh

  • Place insulating foam

  • Pour second layer of concrete

  • Curing for three days
  • Sand blast decorative parts of the wall

  • Wall placement

 


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

"Precast 101," illustrating concrete form release agent application

Posted by Hill and Griffith Company on Aug 18, 2016 5:10:40 PM

(This week's post is a video share from Oldcastle Precast, view the YouTube Channel here. Published on June 19, 2015, it's the complete story of design, engineering, construction, production / pouring of concrete, form release, storage and delivery of the final product to the customer. Very nicely done! Thank you, Oldcastle Precast.)

Concrete-Form-Release-Agent-Application.jpg

Precast concrete is a construction product produced by casting concrete in a reusable mold or "form" which is then cured in a controlled environment. This allow maximum quality control over the process and results in a consistently durable, high quality product. From here it is transported to the construction site and lifted into place.


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, Biodegradable Concrete Form Release, Concrete Release Agents, Concrete Forms, Concrete Form Seasoning, Concrete Casting Supplies, Concrete Voids, Concrete Form Release

Care of Forms and Use of Concrete Form Release Agents

Posted by Hill and Griffith Company on Aug 11, 2016 11:41:40 AM

 

(This week's post is an educational article by Bill Rostine from "Pre-Cast Concrete News." )

Concrete-Form-Release-Agent-Application-1.jpgConcrete formwork is one of the biggest investments a precast or prestress plant has. Therefore, taking care of the forms extends form life and protects a valuable investment. This makes economic sense and contributes to a healthy bottom line.

Care of concrete forms starts with the day-to-day use. Problems on steel forms can occur with inadequate cleaning or with excessive use of wire brushes or sandblasting. Form surfaces can also be damaged by internal vibrators.

Another important aspect of form care is the selection and proper application of a good release agent. Proper application of release agents is necessary for economy and for producing the best product possible and for minimizing form clean up. 

There are three main types of release agents.

The first is the barrier type. These products, as the name implies, provide a barrier between the concrete and the form allowing it to strip. The original, modern-day, form oils were barrier types-diesel fuel, greases, used motor oil, etc. These allowed for a good release, but negatively affected product quality by causing surface voids, staining, and over all poor product appearance. They are heavier in nature and are harder to apply due to their higher viscosity.

The second type of release agent is the reactive type. These are chemically active and contain compounds that react with the free lime in the concrete to produce a soap-like film between the form and the concrete. This type of release agency is the most widely used. They are easily applied in a thin film. Because they can be applied in a thin film by spraying, wiping, or brushing, you can produce stain-free, void-free concrete surfaces. Reactive type release agents applied in a thin film allow the form to strip cleaner which saves on labor costs related to form cleaning and extends the life of the form.

The third type of form release agent is a combination of the other two types.

Grifcote-Concrete-Form-Release-Agent-Sizes.jpgCoating manufacturers and coating formulations, including those of release agents, were affected by the Clean Air Act of 1990 passed by Congress. This law allowed the Environmental Protection Agency to set into motion a process to limit nationwide the amount of Volatile Organic Compound (VOC) that a coating should contain. VOC’s are thought to react with sunlight and cause ground level ozone or smog. The original law called for testing or different VOC’s to see how much, if any, reactive capability a given VOC had with sunlight and the formation of smog. When this testing wasn’t done properly many coating manufacturers (mainly California paint companies and other concerned parties) took the EPA to court to fight the law. After several court fights, lawsuits and rulings during the1990’s, the EPA prevailed and the law limiting VOC’s was allowed to take effect. In September of 1999 release agent manufactures and concrete producers were required to make and use limited VOC products. Some companies, including Hill and Griffith, saw this coming years in advance and were already producing VOC compliant products. All new products were formulated based on the new EPA law. Some states, such as California have stricter rules than that passed nationally.

There are four main application methods-spraying, wiping, mopping  or brushing and dipping. Spraying is probably the most common and efficient method of application. Care should be taken to avoid over application for the reason mentioned earlier. An extremely thin film of release agent can be applied with proper equipment and technique. Working application pressures of 35 to 50 psi are best. Pump unit sprayers or centralized systems with air pressure regulators give a good consistent pressure and work well. Higher pressures put more airborne particles in the air throughout the plant and can be harmful to personnel in the plant. Lower pressures allow for over application, puddling in the form, and waste. A flat fan spray nozzle of .5 gpm maximum size will work with many release agents. Better yet is a flat fan spay nozzle of .1 or .2 gmp spraying a good thin release agent. Many of these thin, chemically active release agents are more expensive per gallon, but with coverage rates at 2000-2500 sq. ft. per gallon the applied cost is much less than a cheaper, less effective release agent. A second type of application is wiping on the release agent. This can be done with a rag or sponge with excellent results. Architectural precasters like this method because over application is eliminated. Some burial vault manufactures use a sponge for application because they clean the form with every application of release agent. A third type of application is by mopping or brushing. When using this method over application can be a problem. As with wiping, the application device must be wrung out in order to achieve the desired results. If puddles occur, they should be wiped up. A fourth method of application is dipping. Dipping systems are fast, labor efficient, and assure total coverage of the form. Dip tanks collect the excess release agent that drains off the form. Over application is probable, but this type of application works well in some operations. Whatever method is used for applying the release agent care should be taken to keep it off reinforcing steel.

Concrete-Form-Rust-Preventative.jpgAnother important aspect of form care is protection of forms in storage. Precast concrete producers, especially those with diverse product lines, occasionally take forms out of service between jobs. The investment in forms needs to be protected from rust and corrosion. Some producers user grease, diesel fuel, or release agent and apply it to the forms. Application with these products needs to be done irregularly with limited protection of the forms. A better choice is a good rust preventative. When shopping for the best product, there are four things to consider.

First is quality of protection, second is length of protection, third is ease of application, and fourth is ease of removal. 

Formwork is a major investment for precast concrete producers. Utmost care should be taken to insure product quality and exend the life of these valuable assets. Money spent taking care of forms now can save hundreds or thousands of dollars in the future and make a concrete business more profitable.


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, Biodegradable Concrete Form Release, Concrete Release Agents, Concrete Forms, Concrete Form Seasoning, Concrete Casting Supplies, Concrete Voids, Concrete Form Release

How Can I Eliminate Surface Concrete Casting Voids?

Posted by Hill and Griffith Company on Aug 4, 2016 2:32:41 PM

 

(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.

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, Biodegradable Concrete Form Release, Concrete Release Agents, Concrete Forms, Concrete Form Seasoning, Concrete Casting Supplies, Concrete Voids, Concrete Form Release

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