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When looking at the ecological properties and qualities of a building material the main
aspects to consider are:
- Composition of raw materials and their environmental
tolerability.
- Properties of the building and their direct and indirect
influence on the environment and inhabitants thereof.
- Environmental aspects of the production process.
In order to evaluate the ecological
quality, all these items have to be investigated and compared against each other. |
| 1. RAW MATERIALS
The main components of a RASTRA® wall are cement, water, and
recycled, expanded polystyrene.
The ecological tolerability of cement is well known. Even
if concrete in some instances, has a bad reputation for causing an unhealthy environment.
This is due to incorrect application and design. The main problems involved in concrete
walls are:
- High water vapor diffusion resistance, causing condensation
and eventually mold.
- Low insulation, unless sandwich designs are used, which
again increase vapor diffusion resistance.
- High temperature difference between the wall and room
temperature, therefore radiation may cause discomfort.
- Sickness due to tightly laid reinforcement forming a Faraday
Cage.
The RASTRA® system uses cement -concrete- in two
different compositions:
The RASTRA® elements contain cement used inhomogeneous
as a bonder to form a cellular structure with just enough porosity to control water vapor
diffusion. The porous, honey-comb like structure, contains small insulating bodies and
tiny air-pockets which are responsible for the low specific heat of the wall surface
material. Therefore, the wall surface maintains at a temperature very close to the comfort
level.
Concrete is also used as the structural
part, poured into the channels of the RASTRA® elements. The disadvantages of concrete, however, are totally
avoided as the concrete is dissolved into a system of small columns rather than using a
solid plate.
RASTRA® elements use a mixture of cement and recycled polystyrene which is
used as a spacer in the cellular lightweight concrete. Plastic materials sometimes are
seen as a hazard to health, particularly when burned. Not so with polystyrene. Polystyrene
is entirely free of CFC's. It is manufactured by polymerization of monostyrene. Styrene is
a hexacyclic molecule composed of carbon and hydrogen (CH[C6H5]CH2), a side product of the
oil refinery process. Polystyrene is a valuable product, widely used for packing, drinking
cups, food trays, etc., however, disposal is not easy, as it is not biodegradable. RASTRA® solves this problem by taking
post consumer polystyrene out of the waste stream - once and forever - and converts it into
new high quality homes.
In the event of a fire, the hydrogen
oxidizes into water vapor, carbon would then be set free and a minimum amount of
carbon dioxide be present. In a fire no health hazard whatsoever would be caused by the
presence of polystyrene. It is evident that fumes created by burning wood f.i. are far
more toxic. As a matter of fact, in a fire, only the few beads close to the surface of a
RASTRA® wall would
melt. Fire tests with open fire at up to 2000°F (1100°C) on RASTRA® walls also revealed that in a
two hour fire less then one inch of the wall material lost its strength, 2 inch deeper the
temperature did not even reach the melting point of the polystyrene beads.
Conclusion: All raw materials used in the
RASTRA® production
are ecologically clean. The specific composition of the RASTRA® blocks help to enhance and improve the
environment and comfort in a RASTRA® building.
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| 2. PROPERTIES OF THE BUILDING
Physical properties of a building may
influence the ecosystem either directly or indirectly. The following list tentatively
classifies the material properties of the RASTRA® Building System in comparison with concrete walls (block or
precast) and framed walls and their repercussions on ecosystem and the environment:
|
Property |
Remarks |
Evaluation |
RASTRA® |
Frame |
Concrete |
| a: heat insulation |
direct:: constant room climate |
+ |
- |
- |
| indirect:: reduces pollution
due to energy consumption, |
+ |
- |
- |
| tightness |
+ |
- |
+ |
| b: mass effect |
direct:: equals out temperature
changes |
+ |
- |
+ |
| indirect:: energy savings |
+ |
- |
+ |
| c: surface
temperature |
direct:: low heat penetration
depth |
+ |
- |
- |
| indirect:: energy savings by
lower thermostat settings |
+ |
- |
- |
| d: vapor diffusion |
direct:: avoids condensation,
constant humidity, avoids molding |
+ |
- |
- |
| indirect:: none |
- |
- |
- |
| e: sound
absorption |
direct:: suppresses reverberation
maximizes living quality, high attenuation |
+ |
- |
- |
| indirect:: none |
- |
- |
- |
| f: formation of
fumes |
direct:: minimizes health hazard
in fire |
+ |
- |
+ |
| indirect:: easier to fight
fire and repair |
+ |
- |
- |
| g: environmental |
direct:: conserves resources |
+ |
- |
+ |
| indirect:: reduces waste |
+ |
- |
- |
Conclusion:
The RASTRA® wall
contributes to a healthy living environment. It also helps indirectly to improve the
environment by conserving energy. Therefore, RASTRA® reduces pollution (Builders use up to 60% smaller units for air
conditioning/heating and save even more on utilities). RASTRA® reuses worthless waste, which would end up
in landfills. Environmentally sound also means "save shelter" and "quality
of living". RASTRA® provides a save shelter; it is fire proof, earth quake save, rodent and termite
proof, resists storms, and provides privacy due to good acoustic attenuation. RASTRA® means higher living quality
with unlimited lifetime at low maintenance cost. |
| 3. ENVIRONMENTAL ASPECTS
Another ecological aspect concerns the
production of the materials. To make a building material totally environmentally friendly
it should not create any pollution during production. Also, raw materials shall be
available or receivable out of sources whose depletion does not harm the environment. A
material would be extremely environmentally friendly and ecologically sound, if it could
use consumer waste as a raw material and does not create waste during the production.
The production of RASTRA® elements can be classified as
ecologically clean. Not only does the production not set free any particles or fumes but
also uses only a minimum of energy. The production of ten square feet of material consumes
only about 1 kWh of electricity, no heating process is involved.
All residues of the production are
immediately recycled into another batch and converted into new RASTRA® elements. Also remnants from
the building site can be shipped back to the plant and recycled.
Using cement, one of the most abundant
resources, and waste polystyrene RASTRA® is an example of a total environmentally friendly product.
The depletion of forests for building
materials has become an issue in many parts of the world with environmentalists and
conservationists. Stunted growth of replanted trees due to acid rain, has moved harvest
schedules back as much as three years in most parts of the world, resulting in shortages.
On the other hand: an average framed home will consume about 10 fir trees.
Consider this: In the minute it
takes you to read this page, a piece of tropical forest the size of 10 city blocks will
disappear forever!
With regard to the solid waste issue, the
RASTRA® product
will help alleviate the volume problem facing the landfills and will result in cost
savings for cities. RASTRA® offers a three fold recycle chain:
INSTEAD OF CHOPPING TREES WE CHOP DOWN POST CONSUMER PLASTICS FOR BETTER LIVING QUALITY.
RASTRA® has been awarded the "Environmental
Protection Award 1977" from the County of Lower Austria and the
California Association of Professional Environmentalists "Achievement
Award 1996" for the ecological achievements in both production and
usage.
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