Low alkaline shotcrete skatepark concrete

Low-Alkaline Shotcrete

Summary
A low-alkaline, high-strength shotcrete was developed by Germany, Italy, and Austria in 1991, it’s better for the environment. It’s now available in North America.

Traditional caustic Shotcrete technology
-Probs with oldschool shotcrete: High-alkaline additives at nozzle creates super caustic dust> skin/lung problems, health hazard. Also crete is porous, lacks strength. Also superfast setting means each layer sprayed on the last, 30% fails to stick, waste and cost. Environmentally, porous so groundwater seeps, caustic alkalines leached out into rivers. Also leachate blocks tunnel drainage.
- Oldschool approach: Gypsum used as setting regulator, keeps concrete workable for several hours.
-Old delilvery: pump shotcrete mix down long pipe.

New Low-Alkaline Shotcrete
Low-alkaline, high-strength shotcrete
High strength, low leachability.
- New Product: Non-alkaline additive instead of gypsum.
- Retards setting for 2-3 minutes for easy spraying and better adhesion, yet allows very rapid hardening.
- No alkaline additives at all.
- Can be premixed with cement instead of added to spraying nozzle.
- Wet aggregate does not trigger setting; only starts when water added at nozzle; can use gravel straight from quarry instead of oven-drying it.
- Crete stays workable for next layer, better adhesion and strength, no wasteful “rebound“.
- Crete denser, less porous.
- Final strength 50% greater than oldschool shotcrete.
- New delivery: New system, load gravel/cement onto hoppers and drive to spraying site.

Development Process
-3 Concrete Co’s (Germany’s Heidelberger Zement (world's fifth largest cement producer)& Italy’s Cementi Buzzi & Austria’s Wietersdorfer und Peggauer)
+ Concrete additives producer (Heidelberger Baustofftechnik)
+ Materials research institute (University of Innsbruck)
= new product
- Developed through BRITE-EURAM funding for unbuilt Ulm/Stuttgart rail tunnels.

Current Status
- New system used successfully on major tunnel projects in Germany and Austria, avail worldwide soon
- New system got 15% of German market in a year.

Commercial Availability
- Heidelberger Zement and Euro/US subsidiaries waiting for approval of patent of technique, will offer worldwide. (Also produced by Cementi Buzzi, soon Wietersdorfer and Peggauer.)
- Conclusion: call Heidelberger Zement, is there a North American distributor yet?
- Circa 1999, this website says “Heidelberger begins North American operation. Heidelberger Zement, parent company of Lehigh Portland Cement, has announced the formation of Heidelberger Calcium Aluminates, a new business that will serve the North American calcium aluminate cement market.“
- So we should ask Lehigh Portland Cement. Should we ask BCRMCA, maybe?
What’s the trade name for this product?
- News flash 01.07.2006 Heidelberger Calcium aluminates website HCA.com says New Company Name
“The HeidelbergCement Group has sold the Heidelberger Calcium Aluminates business line to MEP Mid Europa Partners – a leading independent private equity investment firm focused on Central and Eastern Europe – and the present management.The new group will operate under the name CALUCEM.”
02.07.2007 also on HCA.com: New Website Design New design for www.calucem.com! In the course of our reorganisation we also revised our webdesign. From now on you will find all important information and news about Calucem on this website.
- Check out www.calucem.com

More Information?
Deutsche Umweltstiftung environmental NPO:
- State-approved German environmental NPO, politically independent, volunteer org.
- Goals are nature conservation/ environmental protection. Founded 1982, HQ in Germersheim, motto “Hope through Action”.
-Members mostly scientists and engineers.
- Relevant scientists, judging by description:
- Board of Trustees:
Dr. Rainer Grießhammer, chemist, deputy executive manager of the Öko-Institute (Institute for Applied Ecology), Freiburg
Scientific Advisory Board
Dr. Ulrich Höpfner, chemist, executive manager of the Institute for Energy and Environmental Research, Heidelberg
July 20 emailed them, what about this new concrete, addressed to Griesshammer and Hopfner.

References

“Innovation in Europe”, 1991. E-magazine. http://ec.europa.eu/research/success/en/env/0002e.html

Heidelberger Calcium Aluminates website. HCA.com
http://www.hca.com/content_eng/news/index.html

Calucem website
http://calucem.com

Deutsche Umweltstiftung website.
http://deutscheumweltstiftung.de
Deutsche Umweltstiftung , Postfach 1355, 76713 Germersheim
Tel.: +49(0)7274 / 4767; Fax +49(0)7274 / 77302

---------------
Leftovers
http://cementamericas.com/mag/cement_news_americas_20
This talks about general high-fly-ash concrete, not shotcrete.