Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

RE: Epoxy (et al) Injection

[Subject Prev][Subject Next][Thread Prev][Thread Next]
	>>The term epoxy is misused 
> frequently.  I see it almost every day when an engineer specifies a Hilti 
> "epoxy" anchor that is actually a vinylester resin or methyl methacrelate.
> 
> For applications involving water, I don't think the chemistry of
> vinylesters 
> is very good, and epoxy satisfactory.<<
> 
A clarification:

The original capsule anchor systems put on the market (including Hilti's)
were based on polyester resin formulations, some of which were later found
to exhibit hydrolyzation (reaction with water over time).  Hilti has offered
a vinylester formulation (HEA) for it's capsule anchor system (HVA) since
the mid- 1980s.  This product, in conjunction with HIT C-100, was tested by
the Army Corps of Engineers in Vicksburg for underwater installation.  It
does not exhibit hydrolyzation.

In response to environmental concerns about the use of styrene in anchoring
products, Hilti has  shifted to a styrene-free formulation (urethane
methacrylate) for our latest generation HIT and HVA anchoring systems.  HIT
HY 150 has been installed in combination with HVU (the methacrylate-based
soft capsule for HVA) in submerged concrete blocks and found to exhibit no
loss of bond strength.  In addition, both HIT and HVU have been certified
for use in potable water systems per NSF Standard 061.  Long-term outdoor
tests in Le Harve (on the Atlantic coast of France) show no loss of bond
strength for HY 150 after 5 years of exposure to rain, saltwater, and
temperature extremes.

We also offer a cartridge epoxy, HSE 2421, for those applications where only
epoxies are permitted (Caltrans jobs, for instance) or where a longer set-up
time is desired.

WBR,

John F. Silva, SE
Director, Codes and Approvals
Hilti, Inc.
(415) 507 1690   fax (415) 507 1695
silva(--nospam--at)hilti.com

p.s.  Our crack injection system, CI 060, is based on a low-viscosity epoxy
resin.










> ----------
> From: 	COEngineer(--nospam--at)aol.com[SMTP:COEngineer(--nospam--at)aol.com]
> Reply To: 	seaint(--nospam--at)seaint.org
> Sent: 	Thursday, November 04, 1999 10:05 AM
> To: 	rrollo(--nospam--at)team-psc.com; seaint(--nospam--at)seaint.org
> Subject: 	Re: Epoxy (et al) Injection
> 
> 
> In a message dated 11/3/99 3:29:38 PM, rrollo(--nospam--at)TEAM-PSC.com writes:
> 
> << 1) is it just me or does our industry misuse/overuse the term epoxy and
> has
> that become the Kleenex equivalent in the facial tissue realm or is epoxy
> really the correct "generic" term for all of these 2 component adhesive
> materials.
> 
> 2) having used "epoxy" satisfactorily in the past for similar
> applications,
> should i consider using some of these other materials (with all due
> parameters (tensile and compressive strengths, viscosity appropriate for
> crack width, etc) or shall i go with old standby.
> 3) what are pros and cons of other materials in your experiences.
> 4) are there any other commonly available mfrs so that i don't get too
> proprietary with my specification.
> 
> There are certainly other materials that could or should be used for 
> injection depending on the application.  The term epoxy is misused 
> frequently.  I see it almost every day when an engineer specifies a Hilti 
> "epoxy" anchor that is actually a vinylester resin or methyl methacrelate.
> 
> For applications involving water, I don't think the chemistry of
> vinylesters 
> is very good, and epoxy satisfactory.  There are products available (can't
> 
> remember which ones right now) that are reactive with water which seems
> like 
> a good feature especially if you are injection against head pressure which
> 
> can be difficult. 
> 
> Ourselves as well as Sika and Master Builders seem to supply many projects
> on 
> the west coast, although we do not recommend injecting against a constant 
> head or water flow.
> 
> Howard Silverman, PE
> Covert Operations, Inc.
> Long Beach, CA
> (800) 827-7229
> www.covertoperations.com
>  >>
> 
> 
>