1. EART-SOILASBUILDINGMATERIAL
“The thing that hit me in the eye,
right from the beginning, wasthat an
enormous amount of usewasmade of
mud! Thefirst thing I discovered was
that mud is one thing in one place and
adifferent thing in another. It is used
for different purposes and is used in
different ways! There are different
techniques of sticking it together and
making it into awall or whatever. This
varied considerably, even sometimes in
amatter of afew miles, from one
district to another”
Laurie Baker
3. EART-SOILASBUILDINGMATERIAL
WEPREJUDICED?
•Why isn’t mud considered modern?
• Isit true that mud is not asstrongascement
and steel?
•Are concrete and steel perceived to be better
simply becausethey are seento be the resultof
modern scientific and technologicalprocesses?
• Isthis aproblem of mud itself or is thismerely
aproblem of the modernmind?
4. SOILSOURCE
• Mud required for building canbe takenfrom
the plot itself.
• Thesoil is collected after depth of 60cmsonly.
•Asthe top layer is full of organic matter, itisn’t
used.
•Below it is sand and clay which are dug outin
heaps.
•Donot usehard rock.
• Soil to be used should be devoid of organic
matter.
•Topshould be replaced after excavating.
5. SOILTYPES
• Gravel: Smallpieces of stone varying from the
sizeof apea to that of anegg.
•Sand:Similar small pieces of stone(usually
quartz), which are small but eachgrain,is
visible to theeye.
•Silt:Thesameassandexcept that it is sofine
that you cannot seeindividual grains.
• Clay:Soilsthat stick when wet - but veryhard
when completely dry.
•OrganicSoil:Soil mainly composed of rotting,
decomposing organic matters suchasleaves,
plants and vegetable matter. It is spongy when
wet, usually smells of decaying matter, is darkin
color and usually damp.
6. SOILUSABILITY
•Gravel: alone is of no usefor mud wallbuilding
- the tiny lumps of stone have nothing to bind
them together.
•Sand:similar to gravel, it is of no usefor wall
making by itself - but if mixed with clay, it is the
ideal mud wall building soil.
• Silt: by itself is also no good for buildingwalls.
It will hold together but is not strong.
Furthermore, it will not compact so it is also of
no usefor pressed blocks or rammed
earthwork.
• Clay:canbe rammed or compressedbut
in drying out they often shrink. During
the
monsoon they get damp and expand againand
crack form.
• OrganicSoils:are mainly uselessfor wall
building.
8. COLOURTEST
•Procedure -Observe the colour ofsoil.
•Interpretation
•Deep yellow, orange and red,
ranging to deep brownsindicate
iron content which is good as
building mud.
•Greyish or dull brown, rangingto
dirty white indicates moreclay.
•Dull brown with slightlygreenish
colour indicates organicsoil.
9. TOUCH&SMELL
Procedure
Rubsmall quantity of dry soilon
palm to feel itstexture.
Moisten the soil and rubagain.
Interpretation
Soil that feels coursewhen drybut
sticky when wet contains lumps of
clay.
Soil that feels coursewhen drybut
gritty when wet containssand.
Soil that feels coursewhen drybut
little grittywhen wet contains silt.
If the wet soil gives off musty smell then
it contains organicmatter
10. BISCUITTEST
Procedure
Make asmooth paste from the soil
removing all gravels.
Mould itinto abiscuit of 3cm diameter and
1cm height.
Leaveit todry and observe for shrinkages or
cracks.
Breakthe biscuit to noting how hard it is.
Interpretation
If biscuit cracksor leaves gapfromthe
mould then it contains moreclay.
If its very hard to break then soil contains
more clay.
If it breaks easily and can be crumpled
between finger then it hasgoodsand-clay
proportion.
If breaks and reduce topowder then the soil
hasmore sandor silt.
11. HANDWASHTEST
•Procedure
•Playwith wet soil tillyour hands get
thoroughly dirty.
•Washyour hands to seehow difficultit
is to clean.
•Interpretation
•If hands get cleaned quickly, thensoil
contains more sand.
•If it takes little time to clean and feels
like flour then soil contains moresilt.
•If it feels soapy or slippery and takes
time to clean then soil contains more
clay.
12. CIGARTEST
Procedure
Make asmooth paste from the soilremoving
all gravels.
Roll it on palm to makeacigar.
Slowly push it outside your palm.
Measure the length at which itbreaks.
Interpretation
Length below 5cm - too muchsand.
Length above 15cm - too muchclay.
Length between 5cm to 15cm - goodmixture
of sand andclay.
13. ADHESIONTEST
•Procedure
•Make ball out of wetsoil.
•Pierce aknife into it andremove.
•Observethe knife afterremoving.
•Interpretation
•If little soil sticks on the knife then it has
more silt.
•If lot of soil sticks on the knife then it
hasmore clay.
•Ifthe knife is clean after removal than
the soil hasmoresand.
14. SIEVETEST
•Procedure
•Passsoil from series of standard
sievesset on top of on another
with finest sieve atbottom.
•Observer the soil collectedin
each sieve.
•Interpretation
•Silt will be collectedin
lowermost sieve.
•Gravelswill be collected ontop.
•Sandand lumps of clay will be
collected in intermediatesieves
15. SEDIMENTATIONTEST
•Procedure
•Takeatransparent cylindrical
bottle or jar of 1Lt. Capacity.
•Fill it with ¼soil and ¾water.
•Shakewell and allow it tosettle
for 30min.
•Interpretation
•Coarsegravels will be settled at
bottom, followed by sand, siltand
clay on top.
•Measuring the layers will giveus
the approximate proportions of
each content.
16. STABILISERS
•When the available soil is not suitable
enough for construction then the soil can
be usedby manipulating its composition
by adding suitablestabilizers.
•Stabilizing enhancesthe given
property of the soil type.
•IncreaseTensileand Shear strength.
•Reduceshrinkage.
17. STABILISERS
•Most common and effective stabiliser isSoil
itself.
•Cement, is the best example of amodern
contemporary stabiliser.
•Various other indigenous stabilisersinclude
•Straw
•PlantJuices
•GumArabic
•SugarOr Molasses
•CowDung
•Animal Urine
•TannicAcid
•Oil
18. STABILISERS
•Most common and effective stabiliser isSoil
itself.
•Cement, is the best example of amodern
contemporary stabiliser.
•Various other indigenous stabilisersinclude
•Straw
•PlantJuices
•GumArabic
•SugarOr Molasses
•CowDung
•Animal Urine
•TannicAcid
•Oil
20. EARTHTECHNIQUES
th
• Cob
• Piseor Rammedear
• Adobe
• Pressed bricks
• Wattle and daubmethod
• SYSTEMSOFBUILDING
• COBis good for anything exceptheight.
It is particularly good for curved or
round walls.
• PISEORRAMMEDEARTHis strong and
ideal for solid, squat, single storey
houses.
• ADOBEor SUNDRIEDBRICKScaneasily
cope with two storeyhouses.
• PRESSEDBRICKSsmooth and very strong
and canbuild threestorey.
• WATTLE& DAUBis elegant and fine for
Seismic Zones.
21. COB
• Cobor cobbor clom(in Wales)is abuilding
material consisting of clay, sand, straw, water,
and earth, similar to adobe. Cobis fireproof,
resistant to seismicactivity,[1] and inexpensive.
It canbe used tocreate artistic, sculptural forms
and hasbeen revived in recent years by the
natural building and sustainabilitymovements.
• Thewalls of acob house were generally about
24 inches thick, and windows were
correspondingly deep-set, giving the homes a
characteristic internal appearance. Thethick
walls provided excellent thermal masswhich
waseasyto keep warm in winter and cool in
summer.
• Walls with ahigh thermal massvalue act asa
thermal buffer inside the home.The material
hasalong life span even in rainy climates,
provided atall foundation and large roof
overhang are present.
22. COB
• With only a little water to form a very stiff
mud, a large lump is roughly moulded into
the shapeof ahuge elongated egg.
• Theusual sizeis anything between 12 to 18-
inches, (30 to 40-cm) long and about 6-
inches (15-cm) in diameter.
• Arow of these cobs of mud are laid neatly
side-by-side - preferably somewhat pressed
together.
• Thenanother row of cobsis laid ontop.
• When three or four courseshave been laid,
one above the other, the sidesaresmoothed
over sothat the holes and cracksdisappear.
• Openings for doors, and windows are a
problem, which can be solved by using
temporary vertical planks or shuttering.
• Another very simple shuttering foropenings
is to useempty kerosenetins.
23. RAMMEDEARTH
• Rammedearth, also known astaipa[1]
(Portuguese), tapial(Spanish), and pisé(de
terre)(French), is atechnique for building
walls using the raw materials of earth,chalk,
lime and gravel. It is an ancient building
method that hasseenarevival in recent
years aspeople seekmore sustainable
building materials and natural building
methods. Rammed-earth walls are simple to
construct, incombustible, thermally massive,
strong, and durable.
• Theycanbe labour-intensive to construct
without machinery (powered tampers),
however, and they are susceptible to water
damageif inadequately protected or
maintained. Thesecond method has
developed from the cob wall soasto
standardize or regularize the thickness ofthe
wall.
24. RAMMEDEARTH
• Building arammed-earth wall involves compressing a
damp mixture of earth that hassuitable proportions of
sand, gravel and clay (sometimes with an added
stabilizer) into an externally supported frame or mould,
creating either asolid wall of earth or individual blocks.
Historically, suchadditives aslime or animal blood were
used to stabilize the material, whilst modern
construction useslime, cement or asphalt emulsions.
Somemodern builders also add coloured oxides or
other items, suchasbottles or pieces of timber, to add
variety to thestructure.
• It is also an attempt to increase the strength of the wall
by ramming it. It is known asthe RammedEarth
method.
• Twoparallel planks are held firmly apart by metalrods
and clips or bolts, or by small crosspiecesofwood.
• Stiff mud is thrown in between these two planks and
rammed down with either awooden or metalramrod.
25. RAMMEDEARTH
increases as it cures; it takes some time to dry out, as
much as two years for complete curing. Exposed walls
should be sealed to prevent waterdamage.
• Thecompressive strength of rammed earth can be up
to 4.3 MPa(620 psi). Thisis lessthan that ofconcrete,
but more than strong enough for usein domestic
buildings.[3] Indeed, properly built rammed earth can
withstand loads for thousands of years, asmany still-
standing ancient structures around the world attest.[4]
Rammedearth using rebar, wood or bamboo
reinforcement canprevent failure caused by
earthquakes or heavy storms.Adding cement to clay-
poor soil mixtures canalso increase astructure's load-
bearing capacity
• When one section is completed and hard, the two
boards are moved along and the process isrepeated
• Thetwo planks are then raised up and asecond
course of rammed earth is repeated over thefirst.
• Thecompression strength of the rammedearth
Holy Cross Episcopal Church) in Stateburg,
South Carolina,
EDEN PROJECT
26. ADOBE
• Adobe is anatural building material made from
sand, clay, water, and some kind of fibrous or
organic material (sticks, straw, and/or manure),
which the builders shapeinto bricks usingframes
and dry in the sun.
• Adobe buildings are similar to cob and mudbrick
buildings.Adobe structures are extremely
durable, and account for some of the oldest
existing buildings in the world. In hot climates,
compared with wooden buildings, adobe
buildings offer significant advantages due to their
greater thermal mass,but they are known to be
particularly susceptible to earthquakedamage.
27. ADOBE
• Buildings made of sun-dried earth are common in the
West Asia, North Africa, West Africa,[3] South America,
southwestern North America,Spain
• CompositionAnadobe brick is acomposite material
made of clay mixed with waterand an organic material
such asstraw or dung. Thesoil composition typically
contains clay and sand. Straw is useful in binding the
brick together and allowing the brick todry evenly.{{[9]
}} Dung offers the sameadvantage and is also addedto
repel insects. Themixture is roughly half sand (50%),
one-third clay (35%), and one-sixth straw (15%)by
weight.
• Bricks are made in an open frame, 25 cm (10 in) by
36 cm (14 in) being areasonable size, but any
convenient sizeis acceptable. Themixture is molded by
the frame, and then the frame is removed quickly.
After drying afew hours, the bricks are turned onedge
to finish drying. Slow drying in shade reducescracking.
28. ADOBE
• Thesamemixture to make bricks, without the straw,is
usedfor mortar and often for plaster on interior and
exterior walls. Someancient cultures usedlime-based
cement for the plaster to protect against rain damage
• Reinforcement caninclude manure, straw, cement,
rebar or wooden posts. Experience hasshown straw,
cement, or manure added to astandard adobe
mixture canall produce astronger, more crack-
resistant brick
• An adobe wall can serve as a significant heat reservoir
due to the thermal properties inherent in the massive
walls typical in adobeconstruction.
29. ADOBE
• Blocksshall be kept covered with air tight
polythene sheets for first 48 hrs withrelative
humidity up to 100.
• Polythene sheets shall be removed after 48
hrs and the blocks shall be kept in shaded
area like having enough air circulation.
• Sprinkle water over blocks daily, asmany
times needed, during 28days.
• Write date of production on blockcorner.
• Cover stackstop with coconut leaves orany
other cover to avoid directsunlight.
• Principle is that blocks shall not dryfor
4weeks.
Image:Iran, Bam.
30. COMPRESSEDEARTHBLOCK
• CompressedEarthBlockoften
referred to simply asCEB,is atype of
manufactured construction material
formed in mechanical pressthat
forms an appropriate mix of dirt,
non-expansive clay, and an aggregate
into acompressedblock
• CEBblocks are installed onto the wall
by hand and aslurry made of asoupy
version of the samedirt/clay mix,
sansaggregate, is spread or brushed
very thinly between the blocks for
bonding.
31. COMPRESSEDEARTHBLOCK
• Theadvantages of CEBare in the wait time
for material, the elimination of shipping
cost, the low moisture content, and the
uniformity of the block therebyminimizing,
if not eliminating the useof mortar and
decreasing both the labor and materials
costs.
• CEBcanbe pressed from humid earth.
Becauseit is not wet, the drying time is
much shorter. Somesoil conditions permit
the blocks to go straight from thepressonto
the wall. Asingle mechanical presscan
produce from 800 to over 5,000 blocks per
day, enough to build a1,200 square feet
(110 m2) house in one day.TheLiberator, a
high performance, open source CEBpress,
canproduce from 8,000 to over 17,000
blocks per day.
32. WATTLEANDDAUB
• Wattle and daub method is an old and
common method of building mudstructures.
• Therebamboo and caneframe structure that
supports the roof.
• Mud is plastered over this mesh ofbamboo
caneand straws
• Dueto excessive rainfall the Wattleand
Daubstructures gets washed off.
• However, the mesh of caneor splitbamboo
remains intact and after the heavy rain is
over the mud is plastered onagain.
33. EARTHBAGCONSTRUCTION
• Thismethod was developed from the
bunkers made by the military
• Thebasic construction method begins by
digging atrench.
• Rowsof woven bags(or tubes) are filled with
available inorganic material
• After the foundation is laid, eachsuccessive
layer will have one or morestrands
of barbed wire placed ontop.
• The weight of this earth-filled bag pushes
down on the barbed wire strands, locking
the bag in place on the rowbelow.
• Themost popular type of bagis madeof
woven polypropylene.
• Organic/natural materials such
ashemp, burlap or other natural-fiber bags
(like "gunny sacks") can be used.
34. FOUNDATION
• Often it is feasible to build the walls of a
home on mud, but some more solidmaterial
is needed for the foundation andbasement.
• If stone is locally available it canbeused.
• Thereare times when the topsoil may be
soft and uselessbut there may be
reasonable harder subsoil capable of
carrying the weight of asingle storey mud
house. In this situation remove the soilfrom
the trench you would normally dig for a
stone or brick foundation.
• Slightly dampen the excavated soil and then
replace a part of it to fill the trench about 6
to 9-inches. Ramthis very hard - then repeat
until the trench isfull.
• If there is bamboo is available, it can be used
to make narrow rafts of split bamboo. Having
done the first 6-inches infilling and ramming,
araft of bamboo strips is laid allaround.
35. MORTAR
• SUITABLEMORTARFORMASONRY
• Stabilised Earth Mortar is best suitedfor
masonry using mud blocks.
• Mud mortar shall be stabilised 1.5times
more than the mudblocks.
• Add course sand(0.2 to 2mm) to reduce
shrinkage.
• Prepare plastic mix rather than drymix.
• Ideal mix =soil suitable for mud block +40%
to 50%of sand by weight +7.5%cement.
36. MORTAR
• Testthe mortar before use
• Procedure
– Start with amix of 1 vol. Cement +6vol.
Soil +6 vol. Sand.
– Apply alayer of 1cm mortar on ablock
soaked in water and let itdray in shade.
– Observe the mortar forcracks.
• Interpretation
– If cracksappear, reduce the soiland
increase the sand proportion. 1
cement +5 soil +7 sand.
– If mortar is too crumbly, increase thesoil
and reduce the sandproportion.
1 cement +7 soil +5 sand
• nt.
37. TREATMENTAGAINST
TERMITES
• Mud is the natural home oftermites
soin areaswhere they are common
the sameprecautions have to be
taken asin all buildings to prevent
their moving up into the walls and
eating wooden frames etc.
• Aone-inch thick layer of mortar
(one part of cement to 3-parts of
sand) canbe laid all over the top of
the basement wall before building
the mud walls above it. Thisis
helpful in keeping out bothtermites
and damp.
38. TREATMENTAGAINST
TERMITES
• Evenbetter is to construct an apron
of burnt brick or stone (or it can be
rammed earth) all round the
building (to prevent damageto the
walls by splashing, of rain water)and
this too canbe plastered over with a
rich cement mortar.
• Any thin sheet metal may be laid
over the basement wall with a3-
inch downward projection before
starting to build thesuperstructure
mud wall above. Thisis expensive
but veryeffective.
• There are various chemicals on the
market, which can be used.
39. WATER
• Water and dampness are one of the
major problems for mud as
construction material.
• Thebest way of protecting anywall
from either rain or sun is to have a
good big overhang to yourroof.
• Thesloping, or pitched roof isbetter
because the walls need not be so
high asfor aflat roofedhouse.
• Provide trenches round the houseto
receive dripping water and drain it
away.
