10 October 2007

1. Welcome to theUniversity of the Witwatersrand Investigational Project Presentation 10 October 2007

2. Presentation by: MR. A. James MR. C. Strehlau • Acknowledgements: • Prof. P. Marjanovic and the Faculty of Environmental Engineering • PowerCem Africa

3. “…a presentation into the findings of a report documenting the strength-enhancement and anti-leaching capabilities of a cement enhancer: PowerCem!”

4. 8.6 million km2 and growing sahara desert

5. 4300m and deepening Pacific Ocean

6. 3.5◦C The expected rise in global mean temperatures in the next 100 years

7. Carbon dioxide and the largest single contributor of all green house effects?

8. Every ton of manufactured cement represents 5.1Giga-Joules of energy consumed, equating to • 1200kg of CO2 pumped into the atmosphere. • The use of PowerCem enables the reduction of CO2 equivalent emissions in global cement production by up to 50%.

9. Carbon Dioxide emission comparison:

10. So, what exactly is PowerCem? • PowerCem is: • A fine grained powder • Based on Alkali-earth metals • Comprised of natural & synthetic Zeolites • Environmentally friendly! • Capable of entrapping heavy metals such as Chromium 6+

11. Technically PowerCem is: • Added to mortar or concrete in relatively small amounts (no more than 2 kg/m3 under normal applications) • Proven to increase the strength and flexibility of concrete and cement products • Able to provide for decreased permeability against water ingress and increased resistance to salts and acids

12. Very bold claims! This is how we went about testing some of these claims…

13. The following 4 slides outline: • The practical work undertaken • Our order of approach

14. The steel moulds The mixing device Freshly mixed and cast!

15. Step 1: We cast 192 identically sized cement bars Metals Solution O.P.C. Water Sand PowerCem

16. Step 2: We Mixed 192 specimens to C.E.N. standards H20 175g 0ml 0g 0ml 280g 0g 0ml PowerCem 350g OPC 700g 4ml 175g 0g 40ml CR 6+ 200ml Sand 3500g 280g 0g 350g 0g

17. 1 Day 2 Days 7 Days 14 Days 28 Days Step 3: We tested the bars for compressive and flexural strength after: We made sure that we tested all specimens as closely as possible to the C.E.N. EN 196-1:2005 standards. Step 4: We pulverised the duplicate bars we had cast and sent the remains for chemical analyses and leaching potential.

18. Step 5: The crushed samples were sent to the Wits Environmental chemical laboratory where they were each chemically leached with acidic and alkaline solutions Step 6: This resulting solution was then sent to the (Chemistry Building) Environmental Chemical Laboratory where the liquid samples were analyzed using a Automatic Optical Emission Spectrometer

19. Next we reveal a summary of key findings - after having analysed all structural and chemical test data.

20. Finding 1: Flexural strength comparison after 28 days:

21. Finding 2: Compressive strength comparison after 28 days:

22. Finding 3: Total average gains achieved when including PowerCem in concrete:

23. Finding 4: Total average costs comparison Typically, about 50 R/m3 on materials can be saved, but if carbon credits are taken into account than the effect is close to 200 R/m3

24. Final Finding: The Chromium 6+ immobilisation… • Acidic: 90.51% Cr 6+ Encapsulation • Alkaline: 99.15% Cr 6+ Encapsulation

25. “If we always going to do what we’ve always done, we’re always going to get what we’ve always got…” Solutions to yesterdays problems exist!

26. Lets ensure that fresh water supplies don’t turn to salt water…

27. Keep Greenland frozen!

28. minimise the occurrence of major hurricanes

29. and we’re hoping polar bears will be saved from extinction…

30. “If not us, then who?” • PowerCem is • More durable • Better quality • Cheaper But most importantly, has a significantly smaller ecological footprint.

31. The End. We thank-you for your attention. Questions? 10 October 2007