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Concrete Casting News from the Hill and Griffith Company

Form Oil and Rebar - More on the controversy

Posted by Hill and Griffith Company on Jul 27, 2017 3:08:52 PM

This July 10, 2017, article in PRECAST, INC. "Bond, Reinforcement Bond" concludes with more on the chemistry and physics of form oil and rebar (reinforcing bar) preparation.

"FORM OIL

Like rust, the question of how much detrimental effect form oil has on reinforcing bars is now the subject of research. The current code provisions within ACI 301, "Specifications for Structural Concrete;' section 2.3.1.15, state, "Do not allow formwork release agent to contact reinforcement;' The NPCA Quality Control Manual for Precast Concrete Plants, section 4.3.2, also states, "Reinforcement and other items to be embedded in concrete shall be free of form release agent."

However, recent research (5) casts doubt on this intuitive school of thought and current code language. Until additional data verifies results, form oil should be removed from reinforcing elements, particularly on epoxy-coated and smooth FRP bars.

(5) Belarbi, A, Richardson, NO., Swenty, MK and Taber, L.H, (2010), Effect of Combination on Reinforcing Bar-Concrete Bond, Journal of Performance of Constructed Facilities, ASCE, Vol. 24, No. 3, May -June "

Form-oil-and-rebar.jpg

 

This June 01, 1998 article in CONCRETE CONSTRUCTION references another report that found no significant difference in nine different rebar surface conditions tested in three different ways.

"HOW CLEAN MUST REBAR BE?

Most specifications require reinforcement to be free of deleterious materials. But do common construction contaminants have a harmful effect on bond?

Form-release agents, bond breakers and cement splatter sometimes contaminate reinforcing steel before concrete is placed. However ACI 301-96, "Standard Specifications for Structural Concrete," says: "When concrete is placed, all reinforcement shall be free of materials deleterious to bond." Inspectors often cite this sentence when requiring contractors to remove form-release or bond-breaker overspray and cement splatter from contaminated rebar. But is this work really necessary?

The Aberdeen Group ran a series of bond pull-out tests to assess the effect of contaminants on bond strength. Pull-out tests measure the bond force acting parallel to the bar on the interface between the bar and concrete. Clean, black Grade-60 steel bars and bars with form-release agents, curing compound/bond breakers, cement splatter, motor oil and rust on their surfaces were tested. The form release and curing compound/bond breaker were sprayed on 100% of the rebar surface to duplicate the worst case of contaminant coverage possible during construction. The used motor oil was applied to the entire bar length with a rag, and a cement paste was mixed and applied to various areas of the rebar. To produce rusted rebar, bars were dipped in hydrochloric acid then stored in a moist curing room. The results, based on 27 tests of bars with nine different surface conditions, show that the contaminants didn't adversely affect bond."

What's your opinion? Please add a comment. Thanks.


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, Form Oil, Application of Precast Concrete Form Oil, Grifcote, Precast Concrete Form Release, Concrete Form Release Application, Form Release Application, Concrete Form Oil, Application of Form Oil

Precast Concrete Form Oil Application

Posted by Hill and Griffith Company on May 18, 2017 2:33:37 PM

 

NPCA Virtual Tour of US Concrete, a state of the art precast manufacturing facility acquired by Oldcastle Precast in August 2012

Precast Concrete From Oil Application 1.jpg 

 
Precast Concrete From Oil Application 2.jpg
 
Precast Concrete From Oil Application 3.jpg
 
Precast Concrete From Oil Application 4.jpg
 
Published on Mar 27, 2014

http://www.oldcastleprecast.com
NPCA Virtual Tour of US Concrete, a state of the art precast manufacturing facility acquired by Oldcastle Precast in August 2012

For more information
http://www.oldcastleprecast.com
1-888-965-3227
National Sales & Marketing Office
7921 Southpark Plaza
Littleton, CO 80120
USA


Hill and Griffith 3.5 Gallon Spray Unit

HG Pump Up Sprayer 560.jpg

Benefits and Advantages

  • Components that come in contact with the concrete form oil are non-reactive.
  • Tri-Poxy Coated Steel
  • 4 Gallon capacity; 3.5 gallon usable
  • Funnel top tank for easy fill and closure
  • Poly Shut off with lock on
  • Heavy duty reinforced hose 600 PSI burst
  • 12” pump assembly (pressurizes with fewer strokes)
  • 24” poly curved extension
  • Padded carrying strap
  • All Vitron™ seals and gaskets
  • Lock-On spray control
  • Easy to clean – no internal components
  • Includes 3 spray tips

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 Casting Products, Concrete Release Agents, Concrete Casting Supplies, Application of Precast Concrete Form Oil, Grifcote, Concrete Terms Glossary

Application of Precast Concrete Form Oil

Posted by Hill and Griffith Company on Apr 14, 2017 10:03:48 AM

From the National Precast Concrete Association - Precast Learning Lab

Published on Feb 24, 2017 - Learn how to properly apply form oil at your precast concrete plant.
 

How To - Application of Precast Concrete Form Oil

Spokesperson, "So Lynn, Why is form release application such a critical step in the production process?"
 
Lynn, "It's so critical because it helps you in stripping product out of the form, you get a better overall finished product and it really preserves the life of your mold. As you can see behind me, we have a mold that was stripped earlier today. Before we talk about applying release agent, it’s important to know…"
 

Application of Precast Concrete Form Oil - 1.jpg

NPCA members can view the full video - part of the Precast Learning Lab series - on myNPCA. http://portal.precast.org

Application of Precast Concrete Form Oil - 2.jpg

Application of Precast Concrete Form Oil - 3.jpg

Application of Precast Concrete Form Oil - 4.jpg


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 Casting Products, Concrete Release Agents, Concrete Form Seasoning, Concrete Casting Supplies, Precast Concrete, Gricote, Form Seasoning Concrete Release Agent, Form Oil, Application of Precast Concrete Form Oil

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