Outlandishly strong bolts test holding power of glue/mortar

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Hardman Knott

Gym climber
Muir Woods National Monument, Mill Valley, Ca
Topic Author's Original Post - Jun 28, 2007 - 07:54pm PT
Several years ago, Lord Slime (aka John Byrnes), sent me the following pamphlet.
Some German mad-scientist types used a specially designed, double-stemmed
bolt to test the shearing point of various glues and/or adhesive-mortars.
The idea was to devise a bolt which would knott break before the glue did.

If my memory serves me correctly, Hilti C-100 won the test, and the mortar failed
at an astounding 50 kilonewtons!

If anyone who knows German could translate the gist of the document, it would be
much appreciated. In fact, I will buy you a Radeberger, or perhaps a Franziskaner (or 3).

I scanned these and made them 800 pixels wide, which most closely approximates the actual size. Here's the front cover of the pamphlet:



Inside cover and page 1:















As some of you know, Hilti C-100 was discontinued in favor of HY-150.
In my limited experience, HY-150 was vastly superior on so many (usability) levels,
although I think it failed at a lower pull-force than the C-100. However,
I'm pretty sure it was still well beyond (on order of magnitude) the most
heinous factor-2 climbing fall imaginable.
rwedgee

Ice climber
canyon country,CA
Jun 28, 2007 - 08:07pm PT
Although my German is bit rusty I'll give it a shot.

It seems the gist is......

































Sport climbing is WHACKED!!!

P.S. "outlandishly" don't get to hear that word every day.
Hardman Knott

Gym climber
Muir Woods National Monument, Mill Valley, Ca
Topic Author's Reply - Jun 28, 2007 - 08:20pm PT
Knott sure what a looser is, but maybe better than loser?

I am going to crop and re-scan the result-chart (page 7) above, as it is too small to read...
Clint Cummins

Trad climber
SF Bay area, CA
Jun 28, 2007 - 08:34pm PT
Type or scan to text the "check list for boltsetters" on p.12 and translate using babelfish:

http://babelfish.altavista.com/
Hardman Knott

Gym climber
Muir Woods National Monument, Mill Valley, Ca
Topic Author's Reply - Jun 28, 2007 - 08:40pm PT
Here's an enlargement of page 7; hopefully it is readable now:


k-man

Gym climber
SCruz
Jun 28, 2007 - 08:47pm PT
Is that really Lord Slime?
Chiloe

Trad climber
Lee, NH
Jun 28, 2007 - 09:02pm PT
Is that really Lord Slime?

Seen here climbing on (we hope!) outlandishly strong titanium glue-ins.

Clint Cummins

Trad climber
SF Bay area, CA
Jun 28, 2007 - 09:12pm PT
Dave, on p7 the graphs have force on the vertical axis and bolt types on the horizontal. The bolts are in 3 groups, L to R:
 mortar glass cartridge
 hammer glass cartridge
 cartouche mortar
(photos on p2)
Top graph Gneis = Gneiss, and lower graph Kalk = limestone.
The red caps on the yellow bar graphs are computed using the standard deviation of the tests on the given bolt type.
All bolts above 15kn, so even the lowest strength ones are good.

And the last sentence on p12:

"Rock, mortar and bolts must be coordinated together!"
Prod

Social climber
Charlevoix, MI
Jun 29, 2007 - 08:39am PT
"In English please"

"Hand me the keys you c*#ks@cker, what the f*#k"

Prod
Darryl Cramer

Social climber
Jun 29, 2007 - 01:29pm PT
I thought that HIT-RE500 was the latest and greatest Hilti glue. I place a couple Tortugas in a granite boulder in my front yard (with 150) and was surprised on how easily they rotated. Not confidence inspiring. Someone told me that that was normal and not indicative of the holding power. Any opinions on glue-ins in granite and the whole rotation issue?
Clint Cummins

Trad climber
SF Bay area, CA
Jun 29, 2007 - 02:06pm PT
Darryl,

See Dave's post from 2005 on the rotation issue:

http://www.supertopo.com/climbing/thread.html?topic_id=117902&msg=118438#msg118438

It seems clear that the rotation occurs because the mortar does not bond well with the metal bolt, but due to the deep threads in the bolts, it is not a problem for pullout strength.

Greg Barnes (of ASCA) suggests later in that thread that rotation is commonly eliminated by notching the upper and lower edges of the hole so that the eyebolt goes deeper into the rock.

And you are right of course about the Hilti HIT-RE 500 being unsurpassed for strength in the tests graphed above.

P.S. Nice work on your websites and community projects up in Washington - sorry I don't live close enough to join in the fun!

http://www.washingtonclimbers.org/
Darryl Cramer

Social climber
Jun 29, 2007 - 02:29pm PT
Thanks for the link Clint. I guess if I read/hear the "rotation is ok" comment enough times I'll believe it.
dirtineye

Trad climber
the south
Aug 6, 2008 - 01:30pm PT
Hmmm, rotation is not ok, and certainly would not be OK in a vertical installation like in the other thread.

But in a horizontal installation, with the head embedded (a la tortuga) all the glue really does is hold the bolt in place, in other words, keeps it from pulling straight out.

I don't care if the glue is one with the rock, which I doubt, but as long as the bolt can't wiggle in the hole or pull out, then the shaft and the rock bear all the load.

I'll just bet you that the bolt shaft is sitting against the bottom of the shaft of the drilled hole anyway, hah! Gravity sort of says this ya know. Unless you got some clever way to hold the bolt in the middle of the shaft while the glue cures.

I don't think you have one.
Jaybro

Social climber
wuz real!
Aug 6, 2008 - 02:42pm PT
I like the guy in the twead jacket and muckluks running the roto, now that's a look!
HighDesertDJ

Trad climber
Arid-zona
Aug 6, 2008 - 03:18pm PT
It seems like they pulled straight out on the bolts which wouldn't test the shearing strength of the bolt at all. The tests seem apropos to steep walls but not anything close to vertical.
couchmaster

climber
Aug 6, 2008 - 03:49pm PT
I find it amazing that the UPAT cartridges scored so low. In the South Africa tests in the supersoft rock at Swinburne, they scored the highest! It could be a different mix, but how many glass capsules does UPAT put out? Maybe an updated version?

http://www.saclimb.co.za/softsandstone_report.html


Darryl, I don't believe that they should twist AT ALL! That would make the tensile real low, and epoxy used in 3/8 and 1/2" diameter range usually has stronger tensile than shear. Could it be possible that you are not getting a good mix. Check the dates on the stuff as well. Capsules turn to dust and most of the cartridges have a 2 year shelf life. I think that I need to explore the idea that spinning is OK much more before I'll buy in.

Here's a link to a bunch of other links : http://cascadeclimbers.com/forum/ubbthreads.php?ubb=showflat&Board=31&Number=746006&Searchpage=1&Main=55178&Words=epoxy++billcoe&topic=0&Search=true#Post746006



hamburglar

Trad climber
Denver, CO
Aug 6, 2008 - 03:54pm PT
Are you guys still looking to have this translated? My brother spent a year in Germany on a Fulbright and I think he's still fairly fluent. Let me know and I'll send him an email with the link.
Fishy

climber
Aug 8, 2008 - 06:16am PT
Some of the key points:

* After a spectacular failure in 2000, the german alpine club decided to test a variety of different glues.
* All bolts were tested with an axial pull. Only one type of bolt was used (Salewa, 100 mm).
* Three general styles of glue were tested, including cartridge-type (including the Hilti options)
* Diameter of hole must not be more than 2 mm larger than bolt dia.
* Depth not more than 5 mm more than bolt length
* Holes must be vigorously and thoroghly cleaned - both with a blower and brush. Critical!
* Dont blow using your lungs - you might as well spit in the hole. Use a pump, e.g. Fig 4.
* When using glass cartridges, twist the bolt 15 x around to mix the glue sufficiently. Not necessary for the pre-mixed glues, (e.g. Hilti)
* Restuls are presented in the graphs as mean (n = 5), the red bar shows the St. Dev. (obviously small deviations are better)
The two graphs are for Gneiss and Limestone.
* The tests only went up to 60 kN - several of the glues were still intact at this level. When all 5 reps exceeded 60 kN, there is no red bar in the graph.
* The horizontal red line in the graph is the EN959 level - (15 kN).
* It goes on to compare pros and cons of all types in mroe detail (including curing times, amount to be discarded at the beginning of each new tube etc etc).
* Hilti HIT-RE-500 required the most initial discard.
* Temperature is critical for working/curing times. Can be extremely short in warm temps.
* Correct proportions and thorough mixing are critical! (Duh).

Final Checklist:
1) Bolts at least 80 mm, longer in crappy rock
2) Dont use bolts with smooth surfaces!
3) Use the proper dispenser gun when exact proportions are required.
4) Discard the initial amount
5) Make sure the rock is good, keep at least 15 cm away from cracks etc
6) Ensure a clean hole with a blower (pump) and brush
7) Make sure the hole dimensions accuractly fit with the bolt
8) Keep hole as cry as possible - a little humind is possible, definitely not damp.
9) Finally: Rock, glue and bolt must all fit together!

Summarising the results: It seems that the Hilti HIT-RE-500 is the strongest, but is also not well suited for doing individual holes, and has the largest amount to discard.

A couple of the "Glass-cartridge" types were also extremely strong, and good for individual holes (no waste).

All glues tested exceeded the EN959 standard (15 kN) for axial load.

Pete.
Hardman Knott

Gym climber
Muir Woods National Monument, Mill Valley, Ca
Topic Author's Reply - Aug 8, 2008 - 12:34pm PT
Thank you for the translation! I'm linking your post to the Titanium Bolt Failure thread.
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