2 Environment
Change and variety . . . modelling . . . orientation . . . sunlight . . . colour . . .
view . . . health
Various aspects of the environment which affect the interior appearance
of buildings have been identified in the introductory chapter, and it is the
purpose here to illustrate these aspects in more detail.
CHANGE/VARIETY
Perhaps the most obvious and certainly the most important aspect of
daylighting is its capacity for change, leading to the infinite variety in
appearance of the daylit interior. Change is at the heart of daylighting,
the human body has a capacity for adaptation, particularly in vision, and
the need to exercise this response.
Perception reacts to a degree of change; it is the natural order of things
that the appearance of interior spaces alter with time; and if we have
confidence in their continuing reality, it is because change in their lit
appearance allows us to continue an exploration of the spaces we inhabit;
an entirely different measure of experience to the static qualities of spaces
lit entirely by artificial sources of light during the day; or where there is
no access to the daylight outside. There is a natural process of renewal in
the photochemical processes of the eye as it adapts to accommodate
changes in daylight
First there is the natural change from day to night, from first light until
dark and the need for artificial sources to take over when daylight fades.
Then there are the changes associated with changes of the weather; from
bright sunny days to dark and cloudy or rainy days, there is little doubt that
the human spirit soars when rising in the morning on a bright day, an
experience which is less likely to happen when it is dark and gloomy outside.
Closely associated with changes in the weather are those of the
changes of season, from the winter snows to summer sunlight; each
season will have its own character, which as human beings we
accommodate to in our own way; but what is important is that the
world outside, as experienced through the window, provides necessary
information of the variety of the exterior world; whilst leading to subtle
changes in the appearance of the interior.
MODELLING
Modelling of a shape derives from its physical form, whether round,
square or otherwise, coupled with the way in which light plays on its
surfaces. This is referred to as its modelling and when this derives from
daylight or sunlight, giving light from a single direction, this provides a
form which is perceived by the eye as having meaning, unambiguous.
This is a different experience again from the form of an object or space
resulting from a room lit by artificial light, where the overall light may be
received from a multitude of light sources.
The most usual daylight modelling is that derived from vertical
windows at the side of a room, giving light from a single direction; this
may be helped by windows from an adjacent wall which adds to the
modelling; as the light will still be from the same overall direction, but
adding to the total modelling.
Two examples might be used to emphasize this, the first, a Greek Doric
column where the light of day gives modelling to the entasis on the
rounded surfaces of the column; light which emphasizes its particular
rounded quality together with its verticality. The second example is the
original David statue by Michelangelo seen in its setting in the art gallery
in Florence, lit from daylight above, where the form changes in time as
the day goes by.
A more modern example of the use of overhead daylight to light a
statue is the Charioteer in Delphi (Case Study pp. 170–171).
Daylight by its nature gives meaning and aids our understanding of a
shape or space by its directional flow; a meaning which is emphasized
even further by the addition of direct sunlight.
Interior spaces are judged to be pleasant, bright or gloomy as a result of
the effects of modelling and interiors are judged by the way in which the
spaces and the objects within them are seen during the day to be natural,
or accord to our experience of the natural world.
ORIENTATION
The importance of orientation in a building must be considered at the
outset, when the architect is planning the location of the building on the
site, the aim being to ensure the maximum availability of useful natural
light and sunlight to the interior.
There may of course be severe restrictions where the building is set into
a rigid street pattern, or where there are severe external obstructions; but
even in these circumstances the best use of the daylighting available
should be considered. The architect will have the greatest flexibility to get
the building orientation right on a greenfield site, where he can plan the
site layout to take advantage of the sun path and the availability of the
daylight.
Taking an example from residential buildings in the northern hemisphere,
and using the simple fact that the sun rises in the east and sets in
the west, it would be normal to ensure that those rooms which might
benefit most from early morning light, such as a kitchen, morning room
or even bedrooms, are placed on the east side, whilst those more likely to
be used in the afternoon or evening such as living rooms face south or
west.
There will of course be debate about the desirability of selecting a
specific orientation for a particular use of room and it will be up to the
10 Daylighting: Natural Light in Architecture
The charioteer statue at Delphi, daylit (See
Case Study pp. 170^171)
London Metropolitan University
architect to discuss this with his client, and there may also be conflict with
the orientation of a room when associated with the ability to enjoy a
particular view.
As with all architecture a compromise will need to be established which
best fits the needs of the interior function. What is essential is that the
orientation of a building and the interior layout takes most advantage of
the daylight available and is a factor taken into consideration at the outset
of the building design.
Each architectural programme whether an office, school or church, will
have its own specific needs of orientation, and this is of special
significance where the interior function is one requiring the inhabitants
to sit in fixed positions, often the case in offices or classrooms.
Another aspect of orientation and one where the mere presence of
daylighting is reassuring, is the subconscious desire of people when
inside a building to keep in touch with the outside world, whether to
know the time of day or the nature of the weather. An example of this
might be taken from the modern shopping centre. The Victorians had got
it right when they introduced overhead daylighting from domes or barrel
vaults to their shopping arcades. But in the 1960s many of our early
shopping centres cut out daylight altogether, leading to people finding it
difficult to negotiate their way around or to find the exits.
In one large shopping centre built in Hong Kong in the 1970s where
daylight had been eliminated, visitors felt so disorientated that extreme
measures had to be taken; whilst at City Plaza, another shopping centre
of similar size where daylight had been provided over much of the
multistorey space, it was an immediate success.
There is little likelihood that any shopping centre built now would not
be daylit, there is a public demand for natural light in large open areas
used by the public during the day and whilst the individual shop may be
lit with artificial light to enhance the goods on sale, the public areas will
assist orientation by the provision of daylight. At night the whole
atmosphere will change, contributing to the variety we associate with the
high street shop with artificial light taking over after dark.
SUNLIGHT EFFECT
In his major work Sunlight as Formgiver for Architecture, Bill Lam asks the
question . . . The Sun: Problem or Opportunity? and then proceeds to
show how the answer can really be both, depending very much on the
location of the building. Clearly in hot climates where the sun is overhead
for much of the day the problem is not so much one of welcome, but of
exclusion.
In Britain where the sun is all too rare the answer must clearly be one
of welcome, and an early decison when an architect is planning the
orientation of his building is to encourage the entry of sunlight. Sunlight
adds to the overall level of light when it is available, and adds to those
other environmental factors such as variety and change, modelling and
the creation of delight. There is a different level of experience when
getting up in the morning to a sunlit world, as experienced from the
interior of a building, and it is important that an element of sunlight is
available for some part of the day.
Architects have used the sunlight effect in buildings to create a specific
atmosphere, as for example the shafts of light entering the south side of
our great cathedrals; and on a much smaller scale the use in houses of
daylight and sunlight entry from above to provide necessary functional
light to interior areas, where otherwise little natural light would be
available.
The impression of sunlight is also important seen from windows which
themselves admit no sunlight, but where the view of a sunlit landscape or
buildings may be enjoyed. Whenever sunlight is available there is a
strong desire to perceive it, and disappointment when it is unnecessarily
excluded.
There is of course the obverse side associated with heat gain and glare,
depending upon the orientation of the glazing, and whether people
working in a building are confined to a fixed position. The effects of
direct sunlight can be a disadvantage. Some control may be required in
certain circumstances at certain times of year, and as far as heat gain is
concerned this is best done beyond the window, and is of a sufficiently
flexible nature to be available only when required, or if fixed, not to
inhibit the view.
One of the methods adopted to control the glare effect is to use forms
of glazing which cut down light transmission; these need to be treated
with care to avoid the impression that the interior of a building is
permanently dim, and some glazing is available which reacts to the
external light available, only cutting down the light when the sunlight is
too bright, and might cause glare.
To sum up, the need for the admission of sunlight is important, the
architect must consider this as a first requirement in planning the location
and layout of the building, but in certain circumstances controls will be
needed.
COLOUR
Whilst the colour of daylight will vary from morning to evening, and with
changes in the sky and weather patterns; it is always regarded as the
reference by which colour is judged . . . daylight is regarded as ‘real colour.’
In early stores, such as Harrods, voids were opened in the roof to admit
daylight to sales areas below; whereas for some years this was ignored.
There were several reasons for this, not least being that it was considered
that means of artificial light were more suitable for display, to show off
the goods ‘in a better light.’
This tended to ignore the environmental advantages of daylight and
natural colour, and this has since been recognized in many new large
shopping areas, where the entry of daylight is encouraged for the
provision of environmental light to the store, but where for display
purposes artificial light may be introduced locally to enhance the product.
The old concept of ‘taking something to the light’, by which was meant
daylight, may be less of a necessity if the environmental light gives
natural colour; whilst from the point of view of the shop worker who
must remain in the same environment all day the advantage of natural
light is obvious.
The same applies to office buildings, where people tend to have to
stay in the same atmosphere all day; if workers are too far from a
window and the impression of natural light is greatly reduced, there is
a sense of dissatisfaction. This is recognized by management, ensuring
that for a part of the working day, for example during coffee breaks or
in the office dining room, there is access to daylight, a change of
environment.
It is generally recognized that vision is enhanced by good contrast,
and that the natural colour of daylight increases contrast; it is argued
that this permits lower illumination levels, whilst increasing visibility1.
IMPORTANCE OF VIEW
Although listed last amongst the environmental factors, the question of
view is of special importance. The view out from the window is our
contact with the world outside; it provides the information, which for
reasons already mentioned, allows us to experience the time of day,
changes in the weather, sunlight and the seasons.
At one level, a view satisfies the physiological need for the adaptation
and readaptation of the eye to distance, providing a visual rest centre. For
this reason any view is better than no view, whilst clearly some views will
be better than others. At a different level the importance of a view has
been recognized in research to show that a patient in hospital will recover
more quickly where a window with a view is available.
The content of a view is clearly of importance, and it is the information
it provides which will determine its success. A view out to a blank wall
may be better than nothing but a view out to open countryside, or a
garden will be a different order of experience.
Various views have been analysed in terms of the information
obtained, depending upon the height of the window. In tall buildings
the view may consist entirely of the sky when seen from the interior of
the space, whilst at lower levels the experience of the ground scene
becomes of more importance.
The quality of the exterior view will depend upon the surroundings of
the building, and the height at which it is experienced, but it is of
importance that where a view is available it should be exploited. There
will be instances in large building complexes where internal views from
one part of the interior to another may be had; these will provide the
visual rest centres to satisfy the physiological requirement, but unless
there are views to daylit areas they will lack the amenities of change,
variety and modelling which inform the natural scene outdoors.
The architect should take the question of view into consideration when
planning his building, and when planning the location and detail of the
windows. Some of the finest windows were those of the eighteenth
century in Britain where the refinement of detail of the glazing bar
ensured that the daylight was captured by the bar, led round it, not
impeding the view. This is less necessary today since the size of glass
available is such as to allow large areas of see-through glazing, with no
need for horizontal obstruction.
There are some architectural programmes where it is thought that a
view out may lead to a lack of concentration, as in a school classroom. It
was the author’s experience that classrooms in his school in the 1930s
had windows at high level, precluding a view out; a view which
prevailed until the new school building programmes of the 1960s. Other
building programmes, such as churches or factories, also tend to ignore
the need for a view, and it is perhaps understandable in a building used
only for a short space of time, that the question of view doesn’t figure
large in the architect’s priorities, and in the case of the daylit factory it
would be reasonable to suppose that there might be dangers associated
with lack of concentration when working with potentially dangerous
machinery if a view out were provided.
The question of ‘view-out’ is necessarily associated with ‘view-in’
raising the question of privacy, which in certain circumstances may be
deemed to be of importance. During the day this will generally not be a
problem, as the level of daylight outside will be greater than that within,
inhibiting the view-in but at night the situation will be reversed, and it
may be necessary to resort to some form of blind or curtain, which can
have the desirable effect of ensuring that the window is not seen as a
black hole from the interior at night.
HEALTH
Daylight has long been associated with health, and in Dr Hobday’s book,
The Healing Sun, he reminds us of the work of Vitruvius in the first
century BC with his ten books on architecture. Among the classic
principles of harmony proportion and symmetry, as Vitruvius set out,
he emphasized that architects should select healthy sites for their
buildings, and that careful design of buildings prevented illness. It was
clear that the healthy site was one which was oriented to permit the
introduction of natural light. Vitruvius was the first to study the
qualitative and quantitative aspects of daylight, proposing explicit rules
to assess whether an interior is well daylit.
We may have moved a great deal further than this now, but poor
daylighting and the lack of sunlight is said to be responsible for what is
described as ‘Seasonal Affected Disorder’ or SAD, which affects a large
number of people at certain times of the year due to the lack of sunlight.
It is not a coincidence that given the choice, people prefer to work in
daylight, and choose to locate close to a window. The presence of natural
light at times when it is available in a building, is an important
environmental consideration.
It is often forgotten that people are the major asset and expense of a
company. To get relative costs into perspective, the annual lighting costs
of a person in an office can be the equivalent to only 3–4 hours salary. If
staff are visually impaired through inadequate working conditions and
poor lighting, their productivity will deteriorate and output may decline
on a scale far greater than the gains which might occur from the
installation of more energy efficient (but less user friendly) lighting.
Poor lighting can affect workers’ health, badly designed or poorly
maintained lighting can cause stress and lead to various forms of
complaint, eye discomfort, vision or posture. Dry or itching eyes,
migraines, aches, pains and other symptoms, often known as Sick
Building Syndrome, can be caused by poor or inappropriate lighting
installations. A purely energy efficient approach to workplace lighting,
which pays little or no attention to user comfort, could turn out to be both
ugly and ineffective.
It would be a mistake to adopt energy efficiency as the principal
measure of good lighting, and whilst important, it should be balanced
against those other factors leading to a comfortable and pleasant
environment.
Compressed stabilized earth blocks
C.S.E.B. Technology
C.S.E.B. The making…
Soil selection.
Stabilization
Block yard organization.
Comparative study.
Energy effectiveness.
Cost effectiveness.
Advantages.
Limitations.
Methods of construction.
Case studies.
manufacturers.
C.S.E.B. TECHNOLOGY
NEED:
The continued growth in population is going to aggravate the housing situation unless adequate measures are initiated at grass root level. The only constructional materials available in rural areas are bamboo, timber, straw, reeds and mud. About 80% of the total population still dwells in houses made of these above-mentioned materials. These structures are not economically viable because of the maintenance cost due to annual rainfall, storm, flood etc. and susceptibility of attack by insects. The utilization of earth in building construction specially, for rural housing is the oldest but most commonly used by the majority of rural population.
Earth architecture aims to make extensive use of raw earth as the main building material, thereby using a local resource, which can help developing technologies that are energy saving, eco-friendly and sustainable.
5 most important techiniques in earth architecture are:
rammed earth
Adobe
Cob
Wattle & dob
Compressed earth blocks(most popularised)
c.s.e.b. has promoted earth architecture from a traditional craft to a modern technology.
SOIL SELECTION:
A soil is an earth concrete and a good soil for CSEB is more sandy than clayey. It has these proportions:
According to the percentage of these 4 components, a soil with more gravel will be called gravely, another one with more, sand, sandy, others silty or clayey, etc. The aim of the field tests is to identify in which of these four categories the soil is. From the simple classification it will be easy to know what to do with this soil.
Soil identification
A very few laboratories can identify soils for building purposes. But soil identification can be performed by anybody with sensitive analyses. The main points to examine are:
Grain size distribution, to know quantity of each grain size
Plasticity characteristics, to know the quality and properties of the binders (clays and silts)
Compressibility, to know the optimum moisture content, which will require the minimum of compaction energy for the maximum density
Cohesion, to know how the binders bind the inert grains
Humus content, to know if they are organic materials which might disturb the mix.
Not every soil is suitable for earth construction and CSEB in particular. But with some knowledge and experience many soils can be used for producing CSEB. Topsoil and organic soils must not be used. Identifying the properties of a soil is essential to perform, at the end, good quality products. Some simple sensitive analysis can be performed after a short training.
SIMPLE FIELD TESTS
SMELL THE MOIST SOIL FOR THE HUMAS CONTENT:
SMELLS LIKE ROTTEN : A LOT OF HUMAS & ORGANIC MATTER (NOT SUITABLE FOR C.S.E.B.)
SMELLS MUSTY : HUMAS CONTENT (NOT SUITABLEFOR C.S.E.B.)
AGREABLE SMELL : NO HUMAS( SUITABLE FOR C.S.E.B.)
TEST WITH A PRESS AND IMPROVEMENT OF A SOIL:
FOR THIS TEST, WE MUST MAKE 3 COMPRESSED EARTH BLOCKS WITH THE 4 TYPICAL SOILS(ABOUT 25 LITERS PER SOIL).
OBSERVATIONS TO BE RECORDED:
PREPARATION OF THE SOIL.
COMPRESSION & EJECTION.
HUMID STATE OF THE BLOCK.
DRY STATE OF THE BLOCK IN COMPARISION TO THE BLOCK SAMPLE.
RESULTS:
TYPICAL SOILS ARE NOT SUITABLE FOR CEB, BUT THE CLAYEY SOIL IS THE EASIST TO IMPROVE BY ADDING SAND TO DECREASE THE PLASTICITY.
VERY SANDY SOIL CAN ALSO BE IMPROVED WITH MORE CEMENT STABILIZER & LESS COMPRESSION RATIO.
Possible improvements
Gravel soil
sieving ( 12 to 18 mm ) is indispensable to remove the coarse gravel.
A maximum of 15 % by weight of gravel ( max dia 1 cm ) passing the screen
should be allowed.
3. If the soil is too gravely , fine clay powder can be added but it will be too
difficult to mix.
4. Stabilization can be slightly less than 5 – 4 % by weight of cement should
be sufficient.
Sandy soil
Sieving ( 18 mm ) is only required to loosen and aerate the soil .
Do not sieve in very windy areas, especially if the soil is dry .
Stabilization can be 5 % by weight of cement.
Silty soil
A slight crushing might be required .
Sieving ( 12 mm ) is required if the lumps are too big and cohesive .
Adding 15 – 20 % sand might be needed to give more skeleton to the soil.
Stabilization should be 6 % by weight of cement.
Clayey soil
Crushing might be required.
Sieving ( 12 mm ) is required .
Adding 20 - 30 % sand might be needed .
Stabilization should be 5 % by weight of cement.
6-7 % lime can be added for stabilization . Then no sand is required a
combination of cement lime stabilization can give good results.
Ie 2 % cement + 5 % lime.
STABILIZATION:
Soil stabilization
Many stabilizers can be used. Cement and lime are the most common ones.
Others, like chemicals, resins or natural products can be used as well. The selection of a stabilizer will depend upon the soil quality and the project requirements: Cement will be preferable for sandy soils and to achieve quickly a higher strength. Lime will be rather used for very clayey soil, but will take a longer time to harden and to give strong blocks. The average stabilizer proportion is rather low:
PROCESS:
MEASURING:
THE STABILIZATION IS ALWAYS CALCULATED FROM THE WEIGHT OF DRY MATERIAL. AS IT IS IMPOSSIBLE TO MEASURE
DRY WEIGHT ON SITE , ALL THE WEIGHTS MUST BE CONVRETED INTO VOLUME.
THEN IT IS INDISPEN SABLE TO KNOW THE DRY DENSITY OF SOIL WHICH IS THE WEIGHT OF 1 LITRE OF DRY SOIL.
PROCEDURE TO FIND THE DRY DENSITY OF THE SOIL:
TAKE SOME OF THE LOOSE SOIL TO BE TESTED ,DRY IT UNDRE THE SUN OR ON A FRYING PAN. THEN MEASURE 1 LITER
OF THIS SOIL AND WEIGHT IT ON A SCALE. THE WEIGHT FOUND WILL GIVE THE DRY DENSITY.
USUALLY A STBBILIZATION WITH 5% OF CEMENT IS ENOUGH FOR MOST OF THE BUILDINGS.
EACH SOIL IS DIFFERENT IN WEIGHT & IN QUALITY & THEN EACH STABILIZATION IS DIFFERENT. THEN IT IS ADVISED TO
CONDUCT SOME TESTS TO FIND THE BEST MIXING RATIO OF SOIL & CEMENT & SOME TIMES SAND.
TO CONDUCT THESE TESTS , START WITH THE FOLLOWING MIX (BY VOLUME)
1 VOLUME OF CEMENT = 15 TO 20 VOLUMES OF SOIL
THEN AFTER 1 WEEK CURING , THE TRIAL BLOCKS CAN BE EXAMINED AND ,IF NEEDED , CHANGE THE RATIO OF
SOIL/ CEMENT/ SAND.
USE ONLY ¼ OR 1/3 OF A BAG OF CEMENT AT ATIME.:
TO DO IT , TAKE 3 OR 4 BUCKETS & DIVIDE ,IN 1 TIME, A BAG OF CEMENT INTO THEM. THEN ADD THE SOIL
PROPORTIONALLY TO 1 BUCKET.
NOTE:MIXING 1 BAG OF CEMENT AT A TIME WILL GIVE BAD RESULT BECAUSE THE SETTING TIME OF CEMENT WILL BE
SHORTER THAN THAT OF THE TIME NEEDED TO MAKE THE BLOCK.
SOMETIMES A SOIL WHICH IS TOO CLAYEY SHOULD BE MODIFIED BY ADDING SAND , IF THE STABILIZER IS CEMENT.
THEN ,SOME TEST CAN BE CONDUCTED BY ADDING PROGRESSIVELY SAND TO THE SOIL ,SO THAT THE BLOCKS ARE
NEITHER CRACKING NOR CRUMBLING.
THE FOLLOWING GRID CAN SIMPLY BE USED FOR THE MEASURING OF SOIL AND
CEMENT , SO THAT THE % OF CEMENT WILL BE AROUND 5%
BLOCK YARD ORGANIZATION.
TYPICAL LAYOUT:
MANUFACTURING PROCESS:
DIGGING
SIEVING
MEASURING
DRY MIXING
HUMID MIXING
CHECK MOISTURE CONTENT
MOULDING
CHECK THE BLOCK QUALITY
HUMID CURING
FINAL CURING AND SLAKING
SPECIFICATIONS OF THE PRESS 3000 (AURAM):
High output from the automatic opening: 1000 strokes/day. = 125 Blocks/Hour (plain full size blocks)
Handling of the press with 3 men
Mix preparation and block stacking with 4 men
High and adjustable compression ratio from 1.6 to 1.83(1.77 for 9 cm height)
Micro adjustment of compression ratio
Double compression with the folding back lid
Rollers to move the press on site: Only 2 men are needed.
Block height adjustable with ring spacers: 2.5 cm and from 5 to 10 cm (recommended is 9 cm)
Micro adjustment of block height: 0.5mm accuracy
Interchange ability of moulds
Moulds are provided for making 4/4, 3/4 & 1/2 sizes
Self-stability with the adjustable braces
Very easy maintenance with grease nipples and grease gun.
PRESSES AND MOULDS
ADVANTAGES OF C.S.E.B.
A local material
Ideally, the production is made on the site itself or in the nearby area. Thus, it will save the transportation, fuel, time and money.
A bio-degradable material
Well-designed CSEB houses can withstand, with a minimum of maintenance, heavy rains, snowfall or frost without being damaged. The strength and durability has been proven since half a century. But let's imagine a building fallen down and that a jungle grows on it: the bio-chemicals contained in the humus of the topsoil will destroy the soil cement mix in 10 or 20 years? And CSEB will come back to our Mother Earth!
Limiting deforestation
Firewood is not needed to produce CSEB. It will save the forests, which are being depleted quickly in the world, due to short view developments and the mismanagement of resources.
Management of resources
Each quarry should be planned for various utilisations: water harvesting pond, wastewater treatment, reservoirs, landscaping, etc. It is crucial to be aware of this point: very profitable if well managed ? disastrous if unplanned!
Energy efficiency and eco friendliness
Requiring only a little stabilizer the energy consumption in a m3 can be from 5 to 15 times less than a m³ of fired bricks. The pollution emission will also be 2.4 to 7.8 times less than fired bricks.
Cost efficiency
Produced locally, with a natural resource and semi skilled labour, almost without transport, it will be definitely cost effective! More or less according to each context and to ones knowledge!
An adapted material
Being produced locally it is easily adapted to the various needs: technical, social, cultural habits.
A transferable technology
It is a simple technology requiring semi skills, easy to get. Simple villagers will be able to learn how to do it in few weeks. Efficient training centre will transfer the technology in a week time.
A job creation opportunity
CSEB allow unskilled and unemployed people to learn a skill, get a job and rise in the social values.
Market opportunity
According to the local context (materials, labour, equipment, etc.) the final price will vary, but in most of the cases it will be cheaper than fired bricks.
Reducing imports
Produced locally by semi skilled people, no need import from far away expensive materials or transport over long distances heavy and costly building materials.
Flexible production scale
Equipment for CSEB is available from manual to motorized tools ranging from village to semi industry scale. The selection of the equipment is crucial, but once done properly, it will be easy to use the most adapted equipment for each case.
Social acceptance
Demonstrated, since long, CSEB can adapt itself to various needs: from poor income to well off people or governments. Its quality, regularity and style allow a wide range of final house products. To facilitate this acceptation, banish from your language "stabilized mud blocks", for speaking of CSEB as the latter reports R & D done for half a century when mud blocks referred, in the mind of most people, as poor building material.
LIMITATIONS OF C.S.E.B.
Proper soil identification is required or lack of soil.
Unawareness of the need to manage resources.
Ignorance of the basics for production & use.
Wide spans, high & long building are difficult to do.
Low technical performances compared to concrete.
Untrained teams producing bad quality products.
Over-stabilization through fear or ignorance, implying outrageous costs.
Under-stabilization resulting in low quality products.
Bad quality or un-adapted production equipment.
Low social acceptance due to counter examples (By unskilled people, or bad soil & equipment).
METHODS OF CONSTRUCTION:
Mortars,
like stabilizers, can be made using various proportions of cement and lime. A good environmentally sound mortar for PEBs can be made using 1 part Hydraulic Lime, 4 parts sand and enough water to make the mortar workable.
Pre-packaged mortars, like Brixment brand type-N Coplary Cement, can be used to make a very strong but expensive and environmentally costly mortar. A homemade version of this mortar can be made by mixing 1 part Portland Cement with 6 parts sand and enough water to make workable.
Another strong mortar can be made by combining 1 part Portland Cement, 4 parts lime, 32 parts sand and water.
When mixing mortar, mix all dry ingredients thoroughly before adding water. After laying up bricks in mortar, keep the mortar moist for a day or so.
Mortaring
Mortar for blocks must be applied to the entire surface of the block, as opposed to ribbon mortar beds often used with conventional brick. Full surface mortaring allows for maximum compressive strength. The same soil used in block making, mixed with water to form a slurry, is usually used as a mortar for binding blocks together into floors and walls. Cement can be added to the mortar mix, but this increases the cost. The main advantage of cement mortar is its quick drying speed.
Design Methods
Block size can be varied easily to accommodate a variety of designs. Walls can be sculptured, rounded, or formed into keystone arches to create custom effects. Relatively unskilled labor can be utilized in construction with compressed earth and caliche block.
Design of structural walls using caliche or soil material block must take into account wall height and thickness, size of block, insulation value, and the desired style and finish. Wall height-to-thickness ratio must be adequate for stability.
The relatively low insulation value of soil or caliche block may make additional insulation necessary. The most cost effective wall thickness for insulation value is 12 inches.
Soil or caliche block structures need not have the "pueblo" style if this is not desired. Many architectural styles are possible. A bond or collar beam is necessary if the roof is supported by the walls. This will serve to spread the loads over the entire wall, and stabilize the tops of the walls from horizontal movement.
Vertical reinforcement is difficult with solid block walls, but can be accommodated with the use of reinforced concrete columns at corners, wall openings, and at intervals in the wall. In this case, the soil block becomes an infill panel. Alternatively, walls made more than one block thick may have internal reinforcing between blocks, and have additional insulation between panels. With this method, care must be taken to ensure that the lower block courses are completely dry before additional courses are added.
Soil blocks are typically stuccoed to prevent them from getting wet. Clear finishes may be applied on the interior.
Particular requirements for hollow interlocking blocks
Interlocking blocks can resist disasters (Cyclones, earthquakes and floods), provided that they are hollow, so as to be reinforced with Reinforced Cement Concrete (RCC), at regular intervals. A hollow interlocking CSEB for earthquake resistance must satisfy these requirements:
Extreme consistency in height (1 mm difference maximum is allowed).
Self-aligning to reduce time-wasting adjustments.
Blocks should be hollow and the vertical holes and U shaped blocks should allow casting RCC, according to requirements: To reinforce regularly the masonry vertically and horizontally.
The interlocking keys must interlock transversally and longitudinally to the wall. They should interlock especially well in the length of the wall, which is subject to the shear stress of the earthquake.
Every course must interlock with each other as well as the header of every block in length: to increase the shear strength of the masonry.
Good seating of the blocks on top of each other for properly transmitting the load bearing: All the block area, including the key, must transmit the load.
A binder must bind them: they must not be dry stacked, as the aim is to get a homogenous masonry.
The binder should be a cement-sand mortar of 5 mm thick. It should be quite fluid in order to be workable.
The mould must allow manufacturing of full size blocks but also 3/4 and 1/2 sizes. The blocks must not be cut to match the bond pattern, which will be detrimental to the accuracy, strength and quality of the masonry.
Compressed stabilised earth blocks have a poor bending strength but this is not so critical because the block itself will not bend but the masonry will do. CSEB have very poor shear strength, which is critical in the case of earthquakes. Interlocking blocks will not have a stronger shear strength compared to ordinary CSEB. But the key effect will increase the shear strength of the masonry if the cohesiveness of the material is high enough to keep the link between the key and the body of the block. (Especially shocks and vibrations of an earthquake)
RESEARCHES RELATED TO C.S.E.B.
The following technologies have been mastered and are disseminated since years:
Stabilised rammed earth foundations
Rammed earth walls, rammed manually
Composite plinth – step plinth with CSEB and plinth beam cast in U shaped CSEB
Wide variety of compressed stabilised earth blocks (15 modules available today)
Stabilized earth mortars and plasters
Composite columns – Round hollow CSEB with reinforced cement concrete
Composite beams and lintels – U shaped CSEB with reinforced cement concrete The following technologies are still under research and they will be disseminated only once mastered:
Composite blocks (earth, fibres and stabilizer)
Alternative stabilizers to cement (“homeopathic&rdquo milk of lime and alum)
Alternative water proofing with stabilized earth (soil, sand, cement, lime, alum and tannin from the juice of a seed)
CASE STUDIES:
VISITORS CENTRE, Auroville , India.
ARCHITECT: SUHASINI IYER
. CONSTRUCTED IN YEAR 1998 WITH
GRANDS FROM HUDCO &
FOUNDATION OF WORLD EDUCATION.
.POPULAR & PLESENT PLACE FOR
VISITOR & AUROVILIANS ALIKE.
.A.V.B.C. HAS DEMONSTRATED RITCH
POTENTIAL OF ALTERNATIVE TECHNOLOGIES AND ENERGY SAVING MATERIALS IN IT.
.DESIGNED WITH EMPHASIS ON NATURAL LIGHTING & VENTILATION ALONG WITH RENEWABLE ENERGY SOURCES.
.COMPRISES OF INFORMATION DESK, EXHIBITATION SPACESES, CAFETERIA,HANDICRAFT SHOP ,BOOK SHOPS ETC. SPECIALLY DESIGNIED FOR VISITORS FROM ALL OVER THE WORLD.
SPECIAL FEATURES:
PREFABRICATED FERROCEMENT ELEMENTS WERE USED FOR DOORS & OVERHANGS,THEREBY DOING AWAY WITH THE USE OF WOOD.
A 4-METRE GRID USING LOAD-BEARING PILLARS AND ARCHED OR COBBLED OPENINGS WAS MADE WITH C.S.E.B. TO REDUCE THE COSTS.
SOLAR, WIND, &BIOMASS ENERGY, WATER MANAGEMENT &RECYCLING TECHNIQUES, MUD AND FERROCEMENT TECHNOLOGY , AND RECLAMATION & AFFORESTATION WERE ALL INTEGRATED IN THE PROCESS.
C.S.E.B. FOR DOMES & PREFABRICATED FERROCEMENT CHANNELS WERE CONSIDERED AS THE BEST SOLUTIONS FOR ROFFING.
LIMIT THE USE OF CEMENT & CONCRETE.
RE HABILATED HOUSE IN GUJARAT AFTER KUTCH EARTHQUAKE.
Today Compressed Earth Blocks (CSEB) rival the finest standard bricks available in terms of strength and durability; are highly cost-effective and environmentally-friendly; can be safely used for construction of multi-storey buildings; and lend themselves to a variety of creative and aesthetically pleasing effects.
manufacturers.
RESEARCH ORGANISATIONS:
CRATerre EAG AUROVILLE BUILDING CRNTRE
CBRI (ROORKEE) MUD VILLAGE SOCIETY (DELHI)
ASTRA (BANGLORE) HUDCO
TYPOLOGY OF BLOCKS:
The Auram press 3000 can presently produce 16 different types of Compressed Stabilised Earth Blocks.
These series are available:
Plain square blocks
Plain rectangular blocks
Round blocks
Hollow square blocks
Hollow rectangular blocks
Hollow square interlocking blocks
Hollow rectangular interlocking blocks
Plain square interlocking blocks
Plain rectangular interlocking blocks
Various special blocks
C.S.E.B. The making…
Soil selection.
Stabilization
Block yard organization.
Comparative study.
Energy effectiveness.
Cost effectiveness.
Advantages.
Limitations.
Methods of construction.
Case studies.
manufacturers.
C.S.E.B. TECHNOLOGY
NEED:
The continued growth in population is going to aggravate the housing situation unless adequate measures are initiated at grass root level. The only constructional materials available in rural areas are bamboo, timber, straw, reeds and mud. About 80% of the total population still dwells in houses made of these above-mentioned materials. These structures are not economically viable because of the maintenance cost due to annual rainfall, storm, flood etc. and susceptibility of attack by insects. The utilization of earth in building construction specially, for rural housing is the oldest but most commonly used by the majority of rural population.
Earth architecture aims to make extensive use of raw earth as the main building material, thereby using a local resource, which can help developing technologies that are energy saving, eco-friendly and sustainable.
5 most important techiniques in earth architecture are:
rammed earth
Adobe
Cob
Wattle & dob
Compressed earth blocks(most popularised)
c.s.e.b. has promoted earth architecture from a traditional craft to a modern technology.
SOIL SELECTION:
A soil is an earth concrete and a good soil for CSEB is more sandy than clayey. It has these proportions:
According to the percentage of these 4 components, a soil with more gravel will be called gravely, another one with more, sand, sandy, others silty or clayey, etc. The aim of the field tests is to identify in which of these four categories the soil is. From the simple classification it will be easy to know what to do with this soil.
Soil identification
A very few laboratories can identify soils for building purposes. But soil identification can be performed by anybody with sensitive analyses. The main points to examine are:
Grain size distribution, to know quantity of each grain size
Plasticity characteristics, to know the quality and properties of the binders (clays and silts)
Compressibility, to know the optimum moisture content, which will require the minimum of compaction energy for the maximum density
Cohesion, to know how the binders bind the inert grains
Humus content, to know if they are organic materials which might disturb the mix.
Not every soil is suitable for earth construction and CSEB in particular. But with some knowledge and experience many soils can be used for producing CSEB. Topsoil and organic soils must not be used. Identifying the properties of a soil is essential to perform, at the end, good quality products. Some simple sensitive analysis can be performed after a short training.
SIMPLE FIELD TESTS
SMELL THE MOIST SOIL FOR THE HUMAS CONTENT:
SMELLS LIKE ROTTEN : A LOT OF HUMAS & ORGANIC MATTER (NOT SUITABLE FOR C.S.E.B.)
SMELLS MUSTY : HUMAS CONTENT (NOT SUITABLEFOR C.S.E.B.)
AGREABLE SMELL : NO HUMAS( SUITABLE FOR C.S.E.B.)
TEST WITH A PRESS AND IMPROVEMENT OF A SOIL:
FOR THIS TEST, WE MUST MAKE 3 COMPRESSED EARTH BLOCKS WITH THE 4 TYPICAL SOILS(ABOUT 25 LITERS PER SOIL).
OBSERVATIONS TO BE RECORDED:
PREPARATION OF THE SOIL.
COMPRESSION & EJECTION.
HUMID STATE OF THE BLOCK.
DRY STATE OF THE BLOCK IN COMPARISION TO THE BLOCK SAMPLE.
RESULTS:
TYPICAL SOILS ARE NOT SUITABLE FOR CEB, BUT THE CLAYEY SOIL IS THE EASIST TO IMPROVE BY ADDING SAND TO DECREASE THE PLASTICITY.
VERY SANDY SOIL CAN ALSO BE IMPROVED WITH MORE CEMENT STABILIZER & LESS COMPRESSION RATIO.
Possible improvements
Gravel soil
sieving ( 12 to 18 mm ) is indispensable to remove the coarse gravel.
A maximum of 15 % by weight of gravel ( max dia 1 cm ) passing the screen
should be allowed.
3. If the soil is too gravely , fine clay powder can be added but it will be too
difficult to mix.
4. Stabilization can be slightly less than 5 – 4 % by weight of cement should
be sufficient.
Sandy soil
Sieving ( 18 mm ) is only required to loosen and aerate the soil .
Do not sieve in very windy areas, especially if the soil is dry .
Stabilization can be 5 % by weight of cement.
Silty soil
A slight crushing might be required .
Sieving ( 12 mm ) is required if the lumps are too big and cohesive .
Adding 15 – 20 % sand might be needed to give more skeleton to the soil.
Stabilization should be 6 % by weight of cement.
Clayey soil
Crushing might be required.
Sieving ( 12 mm ) is required .
Adding 20 - 30 % sand might be needed .
Stabilization should be 5 % by weight of cement.
6-7 % lime can be added for stabilization . Then no sand is required a
combination of cement lime stabilization can give good results.
Ie 2 % cement + 5 % lime.
STABILIZATION:
Soil stabilization
Many stabilizers can be used. Cement and lime are the most common ones.
Others, like chemicals, resins or natural products can be used as well. The selection of a stabilizer will depend upon the soil quality and the project requirements: Cement will be preferable for sandy soils and to achieve quickly a higher strength. Lime will be rather used for very clayey soil, but will take a longer time to harden and to give strong blocks. The average stabilizer proportion is rather low:
PROCESS:
MEASURING:
THE STABILIZATION IS ALWAYS CALCULATED FROM THE WEIGHT OF DRY MATERIAL. AS IT IS IMPOSSIBLE TO MEASURE
DRY WEIGHT ON SITE , ALL THE WEIGHTS MUST BE CONVRETED INTO VOLUME.
THEN IT IS INDISPEN SABLE TO KNOW THE DRY DENSITY OF SOIL WHICH IS THE WEIGHT OF 1 LITRE OF DRY SOIL.
PROCEDURE TO FIND THE DRY DENSITY OF THE SOIL:
TAKE SOME OF THE LOOSE SOIL TO BE TESTED ,DRY IT UNDRE THE SUN OR ON A FRYING PAN. THEN MEASURE 1 LITER
OF THIS SOIL AND WEIGHT IT ON A SCALE. THE WEIGHT FOUND WILL GIVE THE DRY DENSITY.
USUALLY A STBBILIZATION WITH 5% OF CEMENT IS ENOUGH FOR MOST OF THE BUILDINGS.
EACH SOIL IS DIFFERENT IN WEIGHT & IN QUALITY & THEN EACH STABILIZATION IS DIFFERENT. THEN IT IS ADVISED TO
CONDUCT SOME TESTS TO FIND THE BEST MIXING RATIO OF SOIL & CEMENT & SOME TIMES SAND.
TO CONDUCT THESE TESTS , START WITH THE FOLLOWING MIX (BY VOLUME)
1 VOLUME OF CEMENT = 15 TO 20 VOLUMES OF SOIL
THEN AFTER 1 WEEK CURING , THE TRIAL BLOCKS CAN BE EXAMINED AND ,IF NEEDED , CHANGE THE RATIO OF
SOIL/ CEMENT/ SAND.
USE ONLY ¼ OR 1/3 OF A BAG OF CEMENT AT ATIME.:
TO DO IT , TAKE 3 OR 4 BUCKETS & DIVIDE ,IN 1 TIME, A BAG OF CEMENT INTO THEM. THEN ADD THE SOIL
PROPORTIONALLY TO 1 BUCKET.
NOTE:MIXING 1 BAG OF CEMENT AT A TIME WILL GIVE BAD RESULT BECAUSE THE SETTING TIME OF CEMENT WILL BE
SHORTER THAN THAT OF THE TIME NEEDED TO MAKE THE BLOCK.
SOMETIMES A SOIL WHICH IS TOO CLAYEY SHOULD BE MODIFIED BY ADDING SAND , IF THE STABILIZER IS CEMENT.
THEN ,SOME TEST CAN BE CONDUCTED BY ADDING PROGRESSIVELY SAND TO THE SOIL ,SO THAT THE BLOCKS ARE
NEITHER CRACKING NOR CRUMBLING.
THE FOLLOWING GRID CAN SIMPLY BE USED FOR THE MEASURING OF SOIL AND
CEMENT , SO THAT THE % OF CEMENT WILL BE AROUND 5%
BLOCK YARD ORGANIZATION.
TYPICAL LAYOUT:
MANUFACTURING PROCESS:
DIGGING
SIEVING
MEASURING
DRY MIXING
HUMID MIXING
CHECK MOISTURE CONTENT
MOULDING
CHECK THE BLOCK QUALITY
HUMID CURING
FINAL CURING AND SLAKING
SPECIFICATIONS OF THE PRESS 3000 (AURAM):
High output from the automatic opening: 1000 strokes/day. = 125 Blocks/Hour (plain full size blocks)
Handling of the press with 3 men
Mix preparation and block stacking with 4 men
High and adjustable compression ratio from 1.6 to 1.83(1.77 for 9 cm height)
Micro adjustment of compression ratio
Double compression with the folding back lid
Rollers to move the press on site: Only 2 men are needed.
Block height adjustable with ring spacers: 2.5 cm and from 5 to 10 cm (recommended is 9 cm)
Micro adjustment of block height: 0.5mm accuracy
Interchange ability of moulds
Moulds are provided for making 4/4, 3/4 & 1/2 sizes
Self-stability with the adjustable braces
Very easy maintenance with grease nipples and grease gun.
PRESSES AND MOULDS
ADVANTAGES OF C.S.E.B.
A local material
Ideally, the production is made on the site itself or in the nearby area. Thus, it will save the transportation, fuel, time and money.
A bio-degradable material
Well-designed CSEB houses can withstand, with a minimum of maintenance, heavy rains, snowfall or frost without being damaged. The strength and durability has been proven since half a century. But let's imagine a building fallen down and that a jungle grows on it: the bio-chemicals contained in the humus of the topsoil will destroy the soil cement mix in 10 or 20 years? And CSEB will come back to our Mother Earth!
Limiting deforestation
Firewood is not needed to produce CSEB. It will save the forests, which are being depleted quickly in the world, due to short view developments and the mismanagement of resources.
Management of resources
Each quarry should be planned for various utilisations: water harvesting pond, wastewater treatment, reservoirs, landscaping, etc. It is crucial to be aware of this point: very profitable if well managed ? disastrous if unplanned!
Energy efficiency and eco friendliness
Requiring only a little stabilizer the energy consumption in a m3 can be from 5 to 15 times less than a m³ of fired bricks. The pollution emission will also be 2.4 to 7.8 times less than fired bricks.
Cost efficiency
Produced locally, with a natural resource and semi skilled labour, almost without transport, it will be definitely cost effective! More or less according to each context and to ones knowledge!
An adapted material
Being produced locally it is easily adapted to the various needs: technical, social, cultural habits.
A transferable technology
It is a simple technology requiring semi skills, easy to get. Simple villagers will be able to learn how to do it in few weeks. Efficient training centre will transfer the technology in a week time.
A job creation opportunity
CSEB allow unskilled and unemployed people to learn a skill, get a job and rise in the social values.
Market opportunity
According to the local context (materials, labour, equipment, etc.) the final price will vary, but in most of the cases it will be cheaper than fired bricks.
Reducing imports
Produced locally by semi skilled people, no need import from far away expensive materials or transport over long distances heavy and costly building materials.
Flexible production scale
Equipment for CSEB is available from manual to motorized tools ranging from village to semi industry scale. The selection of the equipment is crucial, but once done properly, it will be easy to use the most adapted equipment for each case.
Social acceptance
Demonstrated, since long, CSEB can adapt itself to various needs: from poor income to well off people or governments. Its quality, regularity and style allow a wide range of final house products. To facilitate this acceptation, banish from your language "stabilized mud blocks", for speaking of CSEB as the latter reports R & D done for half a century when mud blocks referred, in the mind of most people, as poor building material.
LIMITATIONS OF C.S.E.B.
Proper soil identification is required or lack of soil.
Unawareness of the need to manage resources.
Ignorance of the basics for production & use.
Wide spans, high & long building are difficult to do.
Low technical performances compared to concrete.
Untrained teams producing bad quality products.
Over-stabilization through fear or ignorance, implying outrageous costs.
Under-stabilization resulting in low quality products.
Bad quality or un-adapted production equipment.
Low social acceptance due to counter examples (By unskilled people, or bad soil & equipment).
METHODS OF CONSTRUCTION:
Mortars,
like stabilizers, can be made using various proportions of cement and lime. A good environmentally sound mortar for PEBs can be made using 1 part Hydraulic Lime, 4 parts sand and enough water to make the mortar workable.
Pre-packaged mortars, like Brixment brand type-N Coplary Cement, can be used to make a very strong but expensive and environmentally costly mortar. A homemade version of this mortar can be made by mixing 1 part Portland Cement with 6 parts sand and enough water to make workable.
Another strong mortar can be made by combining 1 part Portland Cement, 4 parts lime, 32 parts sand and water.
When mixing mortar, mix all dry ingredients thoroughly before adding water. After laying up bricks in mortar, keep the mortar moist for a day or so.
Mortaring
Mortar for blocks must be applied to the entire surface of the block, as opposed to ribbon mortar beds often used with conventional brick. Full surface mortaring allows for maximum compressive strength. The same soil used in block making, mixed with water to form a slurry, is usually used as a mortar for binding blocks together into floors and walls. Cement can be added to the mortar mix, but this increases the cost. The main advantage of cement mortar is its quick drying speed.
Design Methods
Block size can be varied easily to accommodate a variety of designs. Walls can be sculptured, rounded, or formed into keystone arches to create custom effects. Relatively unskilled labor can be utilized in construction with compressed earth and caliche block.
Design of structural walls using caliche or soil material block must take into account wall height and thickness, size of block, insulation value, and the desired style and finish. Wall height-to-thickness ratio must be adequate for stability.
The relatively low insulation value of soil or caliche block may make additional insulation necessary. The most cost effective wall thickness for insulation value is 12 inches.
Soil or caliche block structures need not have the "pueblo" style if this is not desired. Many architectural styles are possible. A bond or collar beam is necessary if the roof is supported by the walls. This will serve to spread the loads over the entire wall, and stabilize the tops of the walls from horizontal movement.
Vertical reinforcement is difficult with solid block walls, but can be accommodated with the use of reinforced concrete columns at corners, wall openings, and at intervals in the wall. In this case, the soil block becomes an infill panel. Alternatively, walls made more than one block thick may have internal reinforcing between blocks, and have additional insulation between panels. With this method, care must be taken to ensure that the lower block courses are completely dry before additional courses are added.
Soil blocks are typically stuccoed to prevent them from getting wet. Clear finishes may be applied on the interior.
Particular requirements for hollow interlocking blocks
Interlocking blocks can resist disasters (Cyclones, earthquakes and floods), provided that they are hollow, so as to be reinforced with Reinforced Cement Concrete (RCC), at regular intervals. A hollow interlocking CSEB for earthquake resistance must satisfy these requirements:
Extreme consistency in height (1 mm difference maximum is allowed).
Self-aligning to reduce time-wasting adjustments.
Blocks should be hollow and the vertical holes and U shaped blocks should allow casting RCC, according to requirements: To reinforce regularly the masonry vertically and horizontally.
The interlocking keys must interlock transversally and longitudinally to the wall. They should interlock especially well in the length of the wall, which is subject to the shear stress of the earthquake.
Every course must interlock with each other as well as the header of every block in length: to increase the shear strength of the masonry.
Good seating of the blocks on top of each other for properly transmitting the load bearing: All the block area, including the key, must transmit the load.
A binder must bind them: they must not be dry stacked, as the aim is to get a homogenous masonry.
The binder should be a cement-sand mortar of 5 mm thick. It should be quite fluid in order to be workable.
The mould must allow manufacturing of full size blocks but also 3/4 and 1/2 sizes. The blocks must not be cut to match the bond pattern, which will be detrimental to the accuracy, strength and quality of the masonry.
Compressed stabilised earth blocks have a poor bending strength but this is not so critical because the block itself will not bend but the masonry will do. CSEB have very poor shear strength, which is critical in the case of earthquakes. Interlocking blocks will not have a stronger shear strength compared to ordinary CSEB. But the key effect will increase the shear strength of the masonry if the cohesiveness of the material is high enough to keep the link between the key and the body of the block. (Especially shocks and vibrations of an earthquake)
RESEARCHES RELATED TO C.S.E.B.
The following technologies have been mastered and are disseminated since years:
Stabilised rammed earth foundations
Rammed earth walls, rammed manually
Composite plinth – step plinth with CSEB and plinth beam cast in U shaped CSEB
Wide variety of compressed stabilised earth blocks (15 modules available today)
Stabilized earth mortars and plasters
Composite columns – Round hollow CSEB with reinforced cement concrete
Composite beams and lintels – U shaped CSEB with reinforced cement concrete The following technologies are still under research and they will be disseminated only once mastered:
Composite blocks (earth, fibres and stabilizer)
Alternative stabilizers to cement (“homeopathic&rdquo milk of lime and alum)
Alternative water proofing with stabilized earth (soil, sand, cement, lime, alum and tannin from the juice of a seed)
CASE STUDIES:
VISITORS CENTRE, Auroville , India.
ARCHITECT: SUHASINI IYER
. CONSTRUCTED IN YEAR 1998 WITH
GRANDS FROM HUDCO &
FOUNDATION OF WORLD EDUCATION.
.POPULAR & PLESENT PLACE FOR
VISITOR & AUROVILIANS ALIKE.
.A.V.B.C. HAS DEMONSTRATED RITCH
POTENTIAL OF ALTERNATIVE TECHNOLOGIES AND ENERGY SAVING MATERIALS IN IT.
.DESIGNED WITH EMPHASIS ON NATURAL LIGHTING & VENTILATION ALONG WITH RENEWABLE ENERGY SOURCES.
.COMPRISES OF INFORMATION DESK, EXHIBITATION SPACESES, CAFETERIA,HANDICRAFT SHOP ,BOOK SHOPS ETC. SPECIALLY DESIGNIED FOR VISITORS FROM ALL OVER THE WORLD.
SPECIAL FEATURES:
PREFABRICATED FERROCEMENT ELEMENTS WERE USED FOR DOORS & OVERHANGS,THEREBY DOING AWAY WITH THE USE OF WOOD.
A 4-METRE GRID USING LOAD-BEARING PILLARS AND ARCHED OR COBBLED OPENINGS WAS MADE WITH C.S.E.B. TO REDUCE THE COSTS.
SOLAR, WIND, &BIOMASS ENERGY, WATER MANAGEMENT &RECYCLING TECHNIQUES, MUD AND FERROCEMENT TECHNOLOGY , AND RECLAMATION & AFFORESTATION WERE ALL INTEGRATED IN THE PROCESS.
C.S.E.B. FOR DOMES & PREFABRICATED FERROCEMENT CHANNELS WERE CONSIDERED AS THE BEST SOLUTIONS FOR ROFFING.
LIMIT THE USE OF CEMENT & CONCRETE.
RE HABILATED HOUSE IN GUJARAT AFTER KUTCH EARTHQUAKE.
Today Compressed Earth Blocks (CSEB) rival the finest standard bricks available in terms of strength and durability; are highly cost-effective and environmentally-friendly; can be safely used for construction of multi-storey buildings; and lend themselves to a variety of creative and aesthetically pleasing effects.
manufacturers.
RESEARCH ORGANISATIONS:
CRATerre EAG AUROVILLE BUILDING CRNTRE
CBRI (ROORKEE) MUD VILLAGE SOCIETY (DELHI)
ASTRA (BANGLORE) HUDCO
TYPOLOGY OF BLOCKS:
The Auram press 3000 can presently produce 16 different types of Compressed Stabilised Earth Blocks.
These series are available:
Plain square blocks
Plain rectangular blocks
Round blocks
Hollow square blocks
Hollow rectangular blocks
Hollow square interlocking blocks
Hollow rectangular interlocking blocks
Plain square interlocking blocks
Plain rectangular interlocking blocks
Various special blocks
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