Presentation by:
MR. A. James
MR. C. Strehlau
Acknowledgements:
Prof. P. Marjanovic and the Faculty of Environmental Engineering
PowerCem Africa
“…a presentation into the findings of
a report documenting the
strength-enhancement and
anti-leaching capabilities of a
cement enhancer: PowerCem!”
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%.
0
400
800
1200
Equi
vale
nt k
g's
of C
O2
Emitte
d du
ring
m
anuf
actu
reGreenhouseemmision duringCementmanufacture
Greenhouseemmision duringequivalentPowerCemmanufacture
Carbon Dioxide emission comparison:
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+
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
Technically PowerCem is:
Sand
3500g
OPC 700g
H20 175g
280g
350g
0ml
0ml
0ml
0g
0g
PowerCem
175g
280g
350g
4ml
40ml
CR 6+ 200ml
0g
0g
0g
Step 2: We Mixed 192 specimens toC.E.N. standards
1 Day
2 Days
7 Days
14 Days28 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.
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
Next we reveal a summary of key findings - after having analysed all structural and chemical test data.
0.0
4.0
8.0
Stre
ngth
, M
Pa
0.25 0.4 0.5
Water Cement Ratio
Pure O.P.C.
PowerCem: 1 %mass of O.P.C.
PowerCem: 3 %mass of O.P.C.
PowerCem: 4 %mass of O.P.C.
Finding 1: Flexural strength comparison after 28 days:
Finding 2: Compressive strength comparison after 28 days:
0.0
4.0
8.0
12.0
16.0
Stre
ngth
, M
Pa
0.25 0.4 0.5
Water Cement Ratio
Pure O.P.C.
PowerCem: 1 %mass of O.P.C.
PowerCem: 3 %mass of O.P.C.
PowerCem: 4 %mass of O.P.C.
Finding 3: Total average gains achieved when including PowerCem in concrete:
174%169%
100%
0%
50%
100%
150%
200%
Tota
l Str
engt
h in
crea
se
Normal Cement PowerCem(Compression)
PowerCem(Tension)
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
Final Finding: The Chromium 6+ immobilisation…
Acidic: 90.51% Cr 6+ Encapsulation
Alkaline: 99.15% Cr 6+ Encapsulation
“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!
“If not us, then who?”
PowerCem is
More durable Better quality Cheaper
But most importantly, has a significantly
smaller ecological footprint.