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Concrete Casting News from the Hill and Griffith Company

Coating Tilt Up Concrete Walls

Posted by Hill and Griffith Company on Oct 24, 2019 3:55:17 PM

Originally published in the March 2011 issue of Concrete Construction

Q: The painted surfaces of some of the tilt-up concrete walls on our projects seem to develop blisters, peeling, or flaking shortly after application. Sometimes this occurs after it rains. Is there anything different about tilt-up walls that makes this happen?

A: As with any paint or coating project, the key to good results is paying attention to the three Ps: Prep, Prime, and Paint. Procedures for painting and coating concrete surfaces are different from other surfaces, and tilt-up concrete surfaces do require special preparation.

Causes of Defects on Tilt Up Concrete Walls

Surface Preparation: The most likely reason for blistering and peeling in a tilt-up wall, especially if it occurs shortly after it rains, is failure to remove the mold release agents and bond breakers used for casting the concrete component.

This is the big difference between tilt-up concrete and other forms: It is cast on the jobsite in concrete forms. After the concrete wall or column has cured, a mobile crane tilts the piece up and moves it into place, where it is braced into position and secured. Painting contractors may not always be fully aware of this because they arrive on the jobsite after the walls are in place.

To prevent the concrete from adhering to the molds, contractors apply release agents, or bond breakers, to the mold before the concrete is poured. These release agents can be solvent-based, water-based, oil-based, silicone-based, silicone-free, silicone water-based and many other proprietary combinations. But they all perform the same function—they create lower surface energy between the concrete form and the concrete to mitigate adhesion. The objective is to be able to lift the cured concrete from the casting mold smoothly and cleanly.

Unfortunately, release agent residue also can inhibit adhesion of coatings and paint to the concrete surface. Most painting contractors are aware of this, and paint companies do a good job of educating painters about the need to remove release agent residue before painting or coating tilt-up concrete surfaces. Power washing at the specified pressure using the specified cleaning solvent should do the trick, but there are two cautions.

One, be methodical and thorough when power washing. Two, there is a trend toward making release agents and paints/coatings more compatible, but it is always prudent to power wash the surface first. Even with “compatible” release agents, if too much was applied to one area, it could swamp the system and adversely affect coating adhesion.

All concrete surfaces must be washed before coating to remove dirt, dust, and excess sand anyway, so always take the extra step of power washing tilt-up concrete to remove any release agent residue, whether they are compatible or not.

Read More


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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 Casting Products, Concrete Casting Supplies, Concrete Pipe, Concrete Safety, Precast Concrete, Grifcote FR 50 Concrete Form Release, Bio Gold Concrete Form Release, Grifcote, Concrete Construction Magazine

5 Options for Dry-Cast Concrete Pipe Dip Tank Maintenance

Posted by Hill and Griffith Company on Oct 10, 2019 2:24:06 PM

Originally published in the May-June issue of 2015 PRECAST INC, by Bob Waterloo

Maintaining the optimum reactive level of form release agents in pipe production dip tanks ensures performance and quality. 

Dip tanks play a critical role in the dry-cast pipe production process for many manufacturers. The reactive properties of the fatty acids in the form release agent enable the pipe to release from the pallet/header smoothly. Here’s the problem. The cement/concrete residue left behind when headers are dipped starts to negate the reactive properties of the fatty acids.

Left unchecked, the form release agent eventually begins to lose its effectiveness, pipes will not pull easily from the headers and quality could suffer. The solution: implement a regular program of monitoring and maintenance that keeps the form release at the optimum reactive release level and reduces replacement and disposal costs.

Precast Pipe Dip Tank Maintenance

Benefits of a dip tank
Reactive form release agents are the accepted standard in today’s precast and pipe-forming operations. Fatty acids, which are found in an infinite number of blends, are the most commonly used reactive material. Fatty acids have the unique ability to react with the free lime on the surface of the concrete, which results in a nonviolent chemical reaction. This neutralization (or saponification) forms a metallic soap, allowing the product to release easily.

There are several benefits to using a dip tank to apply form release during pipe-forming operations, including complete coverage, proper release and reduced chance of operator error. However, a common occurrence when using this method of manufacturing is increasing difficulty with “pulls” or “tip-outs” during stripping over a period of production time. This is generally the result of decreased reactive material in the dip tank as contaminants enter the system and negate some of the reactive material.

Maintaining the dip tank
Two areas must be addressed in the preventive maintenance program for this type of equipment:

  1. Regular maintenance to remove sludge that accumulates in the bottom of the dip tank
  2. Regular maintenance of the release agent’s reactive levels for effective release

The sludge generated in the dip tank includes contaminants from previously dipped headers/joint rings. These contaminants negate the reactive portion of the form release. As the reactive portion of the release agent gradually decreases, the possibility of concrete sticking to the headers increases, causing a more difficult release. The rate of decrease is gradual and depends on many factors, including rate of production and amount of contaminants allowed to enter the dip tank.

Ring-Oiling

Removing contaminants
Rather than disposing of the entire tank of form release, transfer it to a holding tank and shovel out the sludge. Because the sludge typically contains petroleum hydrocarbons, disposal should be in compliance with local regulations. Then, transfer the recovered form release agent back into the dip tank and top it off with fresh release agent.

Remember that by adding fresh release agent to the recovered material, rather than using all new release agent, reactive levels will be reduced and release problems will occur sooner unless the reactive portion is tested and brought back to a normal level. The discoloration of the recovered material from the dip tank is not relevant to the release characteristics, or levels of reactive material.

Maintaining reactive release levels
Maintaining the correct level of reactive agent in the form release is quite simple. Test the recovered material and bring the reactive portion back to optimum levels.

Test a sample from the dip tank (less than one ounce is sufficient) for the reactive level through either titration or infrared analysis. Your release agent supplier should be able to tell you the optimum level of reactive material required and may be able to run the analysis for you. Once you determine the level of fatty acids, a number of simple calculations determine the amount of pure reactive agent to be added to the dip tank to bring it back to the optimum reactive level.

After adding the recommended amount of reactive material to the dip tank, use an air lance for mixing for a minimum of two minutes, making sure to cover the entire area of the dip tank. Then top off the dip tank with fresh release agent and air lance again for good distribution.

Depending on the amount of contaminants and reduced reactive material, the timeframe between tests will vary. One way to determine the frequency between tests is to establish a baseline. Begin with tests every 30 days, which should be recorded, until a history can be compiled to determine the needed frequency. The normal frequency of adding more reactive ingredients is typically five gallons for every six weeks of regular production.

In many cases, production workers can see the reduced effectiveness of release agents. It’s important to train them to notify management to add additional reactive material to the dip tank. As usual, science is best, but practical application and analysis are also important.

Total replacement of form release
While removing sludge and maintaining dip tanks by adding new release as needed make sense from an environmental and cost perspective, on occasion, you may feel it necessary to clean the entire dip tank to remove all residual sludge and refill the cleaned dip tank with fresh release agent.

Cost-effectiveness
Dip tank maintenance comes down to five options. Option 1 is the least cost-effective, while Option 5 is the most cost-effective.

Option 1: Drain the dip tank, dispose of the sludge and old release material, then refill only with fresh form release agent.
Option 2: Remove the form release from the dip tank, dispose of the sludge, refill the dip tank with fresh form release, then use the recovered form release to replenish the dip tank as necessary.
Option 3: Remove the form release from the dip tank, dispose of the sludge, refill the tank with recovered form release, then top off with fresh form release.
Option 4: Remove the form release from dip tank, dispose of the sludge, test the recovered form release, add reactive ingredient to bring it back to an optimum level, then top off with fresh form release.
Option 5: If there is not enough sludge to remove but the release is not as good as it should be, test for the reactive level of the release agent in the tank, then add reactive material to return it to an optimum level.

In the long run, a little care and attention to the reactive content level in the dip tank will help to reduce labor costs and maintain or improve casting appearance.


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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 Casting Products, Concrete Casting Supplies, Concrete Pipe, Concrete Safety, Precast Concrete, Grifcote FR 50 Concrete Form Release, Bio Gold Concrete Form Release, Grifcote, Precast Inc Magazine

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

Safety Data Sheet Regulations for Concrete Form Releases

Posted by Hill and Griffith Company on Dec 14, 2018 4:21:30 PM

The New Globally Harmonized System: The Right to Know

Are you or your employees at risk?

New rules, new regulations for concrete form releases. It seems that we are faced with these on an almost daily basis. If you are not up to date, you and your employees could be at risk, and your company could be facing penalties. The United States, in conjunction with other nations, has agreed to new rules regarding employee rights and need to know concerning hazardous materials (previously covered in Material Safety Data Sheets, or MSDSs). The new reference will be called Safety Data Sheets (SDSs).

We use many materials in the precast industry, and many of them have given us better castings – but always at a price. That price often comes in the form of special care and handling of materials that are classified as hazardous, including those that are considered flammable or combustible, or cause irritation, sensitivity, corrosion, and are proven or suspected carcinogens. Part of our responsibility is to help reduce the threat, whether minor or serious, to our workers and the environment. OSHA commonly refers to it as “the right to know.”

You are probably already aware of the new rules and regulations regarding SDSs and the training necessary to comply with the new Globally Harmonized System (GHS). This applies not just to precast suppliers, but the precast producer is also responsible for complying with certain regulations including training.

GHS Label Elements

In making a brief survey of precast and pipe producers, I found that while they are generally somewhat aware, most do not realize the full scope of the new regulations. Here is a quick overview of the GHS.

First, the MSDS is a thing of the past. It is now being replaced by the SDS, and while the format is very similar, there are some significant changes. You will need to have SDSs from all of your suppliers. Some states will have additional requirements, although they are not necessarily addressed here. 

June 1, 2015, is the time for everything to be in place. An additional review of the policies will occur June 1, 2016, after which there may be additional changes. However, some of the laws are already in effect. If you are not in compliance with them yet, you will need to move quickly. 

The Employer is responsible for:  

  • Identifying and maintaining a list of hazardous chemicals known to be present at the plant

  • Obtaining, keeping up to date and providing employee access to SDSs

  • Being sure that all hazardous materials are properly labeled

  • Presenting a training program for all employees who will be exposed to these hazardous materials

  • Having a written hazardous communication program in place

  • Having SDS information available to employees and ensuring they have access to the company training program

  • Ensuring that employees read and understand the SDSs and the label on the containers of all hazardous material

Perhaps the first area of concern to producers is the fact that employee training of the new GHS was to be completed by Dec. 1, 2013. If you haven’t already done so, now is the time to do it. 

Your training program must include:

  • The requirements of the standard

  • Places where hazardous chemicals are present in your work area

  • The location and availability of the written program, the chemical inventory and the SDSs

  • How to access the SDSs in your work area

  • How to read the SDSs

  • How to read the GHS-style container labels

  • Any specific labeling used in-house if different from the standards

  • Specific hazardous chemicals in the employees’ immediate work areas

  • How to detect the presence of a release of a hazardous chemical

  • The physical and health hazards of those chemicals

  • Measures you can use to protect yourself against these hazards

  • Required personal protective equipment (PPE) available and how to use it 

Next, you must have a written program and a list of all SDSs spelled out in the program.

All SDSs must be in English (worldwide), and additional languages also must be available to convey to employees in their native language or a language they understand. The manufacturer of the hazardous material is responsible only for supplying the SDS in English, so you are responsible for any additional languages.

Materials that fall under the GHS include: 

  • Health hazards

  • Physical hazards

  • Environmental hazards 

  • Hazards not other classified

  • Other hazardous chemical 

Hazard Warning Levels

Any material falling under the “hazardous” classification must have the following information on the label:

• Product identification
• Pictogram
• Signal word
• Hazard statement(s)
• Precautionary statement(s)
• Name, address and telephone number of the chemical 
manufacturer, importer or other responsible party 

Hazard Warning Labels

While there is no specific format for the label, all of the above must be clearly shown.

Pictograms are also required for quick identification of the hazard. On the SDS itself, there will now be a total of 16 sections – all of which must be completed for any material that falls under the hazardous classification: 

1. Identification

2. Hazard(s)identification

3. Composition/information on ingredients

4. First-aid measures

5. Firefighting measures

6. Accidental release measures

7. Handling and storage

8. Exposure controls/personal protection

9. Physical and chemical properties

10. Stability and reactivity

11. Toxicological information

12. Ecological information

13. Disposal considerations

14. Transport information

15. Regulatory information

16. Other information (including date of preparation or last revision) 

 

As a final note, all hazardous materials in your workplace must be cross-referenced by supplier and/or manufacturer.

These new OSHA regulations place an additional burden not only on the manufacturer/distributor, but also on the end user– you! Owners and operators are now responsible for keeping employees aware of any hazardous material on the premises, and all new employees must go through this training before being allowed in the workplace. OSHA will likely ask about the GHS in your workplace and assess stiff fines for not being in compliance.

The National Precast Concrete Association offers its members a free webinar titled “Webinar: Guide to Globally Harmonized System Documentation” by logging on to precast.org/ education.


Concrete Form Release SDS paper 3-14 

By Bob Waterloo, published in the March/April 2014 issue of PRECAST INC.

Bob Waterloo is Technical Sales Manager, Concrete Release Agents, Hill and Griffith Co., based in Cincinnati. For additional information, contact him at bwaterloo@hillandgriffith.com

The online Precast Inc. magazine article is available at: precast.org/2014/03/new-globally-harmonized-system-right-know/.

For a PDF of this article, click here or on the image.


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: Concrete Form Release Agents, Concrete Release Agents, Concrete Forms, Concrete Casting Supplies, Concrete Pipe, Concrete Form Release, Saftey Data Sheet

Concrete Pipe - Its History and Production.

Posted by Hill and Griffith Company on Jul 28, 2016 2:06:41 PM

(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.)

Concrete-Form-Release-Agent-1.jpgConcrete pipe has a well established history and reputation for being a long lasting, serviceable material. The 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.

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

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