Concrete Blocks

Technical Data
Building element Wall
Size Various sizes
Mixing ratio 1 cement : 6-8 aggregate
Cement used per m3 250 - 300kg
Resistance to earthquakes Very good
Resistance to typhoons Very good
Resistance to rain Very good
Resistance to insects Very good
Climatic suitability All climates
Stage of experience Widely used method
2
Production costs per m Rp. 55,000
Durability Approx. 30 years

Short Description Advantages

Concrete block construction has gained importance and Technical advantages
has become a valid alternative to fired clay bricks. The Solid blocks:
essential ingredients of concrete are cement, aggregate
n High compressive strength, resistance to weathering,
(sand, gravel) and water. Concrete blocks are produced in impact and abrasion
a large variety of shapes and sizes. They can be produced
n Capability of being moulded into components of any
manually or with the help of machines.
shape and size
Most commonly used concrete blocks are sized: n Good fire resistance up to about 400°C

Length: 40cm (half blocks: 20cm) n Rapid construction

n Very good stability
Height: 20cm
Width: 8/10/15/20cm Hollow blocks:
ArCli uses the sizes 14,5 x 29 x 14cm, 14,5 x 14,5 x 14cm n Can be made larger than
(width x length x height) solid blocks
n Are lighter in weight
Solid blocks have no cavities, or- according to US stand-
ards- have no voids amounting to not more than 25% of the n Construction of walls is
easy and quick
gross cross-sectional area.
n The voids can be filled with
Hollow blocks are the most common type of concrete steel bars and concrete,
blocks, having one or more holes that are open at both achieving high earthquake
sides. The total void area can amount to 50% of the gross resistance
cross-sectional area. n The air space provides
good thermal insulation
n The cavities can be used
for electrical installation
and plumbing
Economic advantages
n Production can be started
with little capital.
n Less working time required
for brick laying work with
concrete blocks.
n Less mortar consumption
n Generally, production costs
of concrete blocks are
slightly lower than of fired
bricks.
 n Add some water.
Limits of Application
n Raw materials must be locally available, of good quality
and economically viable.
n Relatively large amount of cement is needed, which can
be expensive and difficult to obtain.
n Special knowledge and experience of the production
n In hot climates, the fresh mix must be shaded from the
process is needed.
sun.
2. Moulding:
Raw Material
n Put the mixture into wooden
Cement: or steel mould boxes or
n Ordinary Portland Cement moulding machine.
n Special cements

Aggregate:
n Sand or gravel
n Max. particle size of coarser aggregates is 10mm.
n Suitable aggregates are usually obtained from natural n Demould blocks immediately
sources (river beds, gravel pits, volcanic deposits) or after compaction.
from industrial by-processes (granulated blast furnace
slag, sintered fly ash).
Cement-Aggregate Ratio:
n Suitable proportion of aggregate to cement must be
found by testing
n Common ratios are 1:6, 1:8
n Test the quality of blocks produced

Water-Cement Ratio: 3. Curing:

n Only drinking quality water should be used to mix the n Cover demoulded blocks with plastic sheets for 24hrs.
concrete. n Keep the concrete blocks moist by keeping under water
n Recommended water-cement ratio is 0.5 in tanks or by regularly spraying with water for 7 days.
4. Storing:
Equipment n Do not expose to direct sun light; keep the blocks in a dry
and covered area.
n Masonry tools
n Store for 2 weeks before usage.
n Mixers: Pan mixers; Trough mixers
n Blockmaking machine: Hand-operated; “Egg-laying” mo-
bile machines; fully mechanised stationary machines
Skills required
Concrete making and masonry skills

Costs for Equipment

n Manual press machine Rp. ####
n Semi automatic press machine Rp. ####
n Mould full size block Rp. ####
n Mould half size block Rp. ####
n Hand press Rp. ####

Equipment Supplier
Production Process Parry Associates, UK
www.parryassociates.com
1. Batching and mixing:
n Batch aggregates and ce- TARA Technology and Action, India
ment by weight. www.devalt.org/TARA/
n Mix cement and aggregates Appro-Techno, Belgium
using mattock, shovel or
www.appro-techno.com
mixer until it reaches homo-
geneous condition. Local suppliers (for hand operated equipment)

Text & Layout by: Skat, Vadianstrasse 42, CH-9000 St.Gallen, Switzerland, phone: +41 71 228 54 54, mail: info@skat.ch, web: www.skat.ch
Cement Floor Tile
Technical Data
Building element Floor
15 x 15 x 1.4cm (w x l x t)
Sizes in cm 20 x 20 x 2.0
25 x 25 x 2.4
30 x 30 x 2.6
Mixing ratio 1 cement : 5 aggregates
Cement used per m3 300 kg
Weight per m³ 2.3 t
Resistance to earthquakes -
Resistance to typhoons -
Resistance to water Very good
Resistance to insects Very good
Climatic suitability -
Stage of experience Widely used method
Production costs per m3 Rp. 20,000
Durability Approx. 30 years

Short Description Limits of Application

Cement Floor Tiles are used for the finishing of indoor n Raw materials must be locally available of good quality
floors. and economically viable
n Relatively large amount of cement is needed which can
They are prefabricated in diverse sizes according to the
be expensive and difficult to obtain
planned design and needs of the customer. They are pro-
n Special knowledge and experience of the production
duced either through the wet method (wet head tile) or the
process is needed
dry method (dry head tile). The upper layer is made from
portland cement with or without coloring or additives. The n Can be laid only on solid under-structure
bottom layer is made from a strong mixture of cement and
sand (1:5).
Cement Floor Tiles are an excellent value-for-money and a
good alternative to ceramic tiles
Raw Material
Head Layer Cement
Body Layer
n Ordinary Portland Cement
n Special cements and colours

Aggregate
n Sieved stone dust
Advantages n Sand (sieved with Ø 5 mm sieve)
n Gravel
Technical advantages
n Max. particle size of coarser aggregates is 10mm
•n Capability of being moulded in different sizes, shapes,
and colours n The ideal aggregate is of hard fine aggregate (passing an
ISO 8mm sieve) by using 8 - 4 - 2 - 1 - 0,500 - 0,250 mm
n Good stability
sieves
n Easy to produce
n Aggregate must be well cleaned
n Easy laying
n Good indoor climate (balanced humidity; cool) Cement – Aggregate Ratio
n Various attractive patterns can be formed •n A test is recommended to select the appropriate mixing
of aggregate and cement
Economic advantages
•n Common ratio is 1:5
n Production can be started with little capital
n Can be massed produced Water-Cement Ratio
•n Equipment to produce tiles can be easily made by local n Only drinking quality water should be used to mix the
workshop concrete
n Can be an attractive business for small-scale enterprise n Recommended water-cement ratio is 0.4
 4. Storing
Equipment
n Do not expose to direct sun light, keep the tiles in a dry
n Mixers : Pan Mixers, Trough mixers and covered area
n Matras cement tile n Store for 2 weeks before usage
•n Manual moulds
•n Pallet
n Masonry tools

Costs for Equipment

n Mechanized equipment sets range up to 5000 USD
n Hand operated equipment is 150 USD

Production Process Skills Required

1. Batching and mixing n Concrete making and masonry skills
n Prepare mix for cement tile with the ratios of 1:5 (cement/ n Special training at ArCli is recommended
aggregate) for the body layer, and 1:0.2 (cement/ stone
dust) for the head layer.
n Add some water
n In hot climates, the fresh mix must be shaded from the
sun

2. Moulding
n Prepare first the head layer:
n Fill the mix into prepared tile moulds up to fixed level to
obtain uniform thickness of first layer
n Secondly, prepare the body layer:
n Fill the prepared mix in stages on top of the first layer
until the mould is completely filled
n Demould tiles after compaction

3. Curing
n Cover demoulded tiles with plastic sheets for 24 hours
n Keep the tiles moist by keeping under water in tanks or
by regularly spraying with water for 5 days.

Text & Layout by: Skat, Vadianstrasse 42, CH-9000 St.Gallen, Switzerland, phone: +41 71 228 54 54, mail: info@skat.ch, web: www.skat.ch
Concrete Beam
Technical Data
Building element Beam of slab system
Mixing ratio 1 cement : 4 aggregates
3
Cement used per m 460 kg
Resistance to earthquakes Very good
Resistance to typhoons Very good
Resistance to rain Very good
00
.4
ax

Resistance to insects Very good

m

Climatic suitability All climates

Stage of experience Experimental
6

Production costs per m2 Rp. 95,000 - 115,000

per beam
10
Durability Approx. 30 years

Short Description Raw Material

n Prefabricated reinforced concrete beams with integrated Cement:
iron brackets n Ordinary Portland Cement
n Beams are produced for slab system
Aggregate:
n Appropriate dimensions for the reinforcement have to be
calculated according to span length and load n Sand or gravel
n Max. particle size of coarser aggregates is 10mm
Size: 10 x 6 x max. length 400cm
n Suitable aggregates are usually obtained from natural
sources (river beds, gravel pits, volcanic deposits) or
from industrial by-processes (granulated blast furnace
slag, sintered fly ash)

Advantages Cement-Aggregate Ratio:

n Suitable proportion of aggregate to cement must be
Technical advantages found by testing
n High structural strength
n Common ratio is 1:5
n Good fire resistance up to about 400°C
n Rapid construction Water-Cement Ratio:
n Only drinking quality water should be used to mix the
Economic advantages concrete.
n Production can be started with little capital n Recommended water-cement ratio is 0.5
n Economises on building material, through longer spans
Steel reinforcement:
n Less wood is consumed
n U 24, U 39

Limits of Application Equipment

n Span length is limited to max. 4m n Ordinary masonry equipment: spades pans, sieves, trow-
n Skilled labourers and engineers required els, sand and cement batching boxes, balance, etc.
n Engineer has to calculate reinforcement dimensions and n Testing equipment
details n Shuttering for beam moulds
Production Process Skills Required
n Prepare the cement mix using cement, aggregates, and n Special training is needed
water (cement-aggregates ratio is 1:5) n Engineer has to calculate reinforcement of beams

Equipment Supplier
No special equipment required

Costs for Equipment

n Prepare formwork by placing it on an even and neat floor No special equipment required
with 10cm empty spaces in between
n Place the steel reinforcement and stirrups in the beam
moulds
n Cast the moulds with the mortar to produce the beams
n Cover with plastic sheet; keep the beams moist
n Let the beams cure for 7 days before demoulding
n Store the beams for 2 weeks before use

Text & Layout by: Skat, Vadianstrasse 42, CH-9000 St.Gallen, Switzerland, phone: +41 71 228 54 54, mail: info@skat.ch, web: www.skat.ch
Rooster
Technical Data
Building element Wall

Size 29 x 14.5 x 14cm

(length x width x height)
Mixing ratio 1 cement : 6-8 aggregates
3
Cement used per m Depends on ratio and pattern
Resistance to earthquakes Very good
Resistance to typhoons Very good
Resistance to rain Very good
Resistance to insects Very good
Climatic suitability All climates
Stage of experience Widely used method
Production costs Rp. 50,000
Durability Approx. 30 years

Short Description Limits of Application

Ventilation Blocks (also known as Rooster) are widely used n Can not be used as load bearing elements
in walls (external and internal) to maintain necessary air n Raw materials must be locally available of good quality
circulation within buildings and screens. They can be also and economically viable
used for toilet parapets and fencing walls. n Relative large amount of cement is needed which can be
The empty spaces within expensive and difficult to obtain
the ventilation block can n Special knowledge and experience of the production
be designed according process is needed
to the required volume
of fresh air circulation.

Raw Material
Cement

Advantages •n Ordinary Portland Cement

•n Special cements
Technical Advantages
n Capability of being moulded into components of any Aggregates
shape and size n Sand and gravel
n Can have same size as concrete blocks n Max. particle size of coarser aggregates is 10 mm
n Good stability, resistance to weathering, impact and
n Suitable aggregates are usually obtained from natural
abraison
sources (river beds, gravel pits, volcanic deposits) or
n Easy to produce from industrial by-processes (granulated blast furnace
n Can be easily built into walls slag, sintered fly ash)
n More durable than window shutters
Cement – Aggregate Ratio
Economic Advantages •n Suitable proportion of aggregate to cement must be
n Production can be started with little capital found by testing
n Can be massed produced n Common ratio is 1: 5
n Equipment to produce rooster can be easily made by lo-
cal workshop Water-Cement Ratio
n Production of roosters can be easily combined with con- n Only drinking quality water should be used to mix the
crete blocks concrete
n Can be an attractive business for small-scale enterprise n Recommended water-cement ratio is 0.5
Equipment Costs for Equipment
n Mixers: Pan mixers, Trough mixers n Manual press machine Rp. ####
n Matras Rooster n Semi automatic press machine Rp. ####
n Manual moulds n Block mould Rp. ####
•n Pallet
n Masonry tools

Production Process Skills required

1. Batching and mixing n Concrete making and masonry skills
n Batch aggregates and cement by weight n Special training at ArCli is recommended
n Mix cement and aggregates using mattock, shovel or
mixer until it reaches homogeneous condition
n Add some water
n In hot climates, the fresh mix must be shaded from the
sun

2. Moulding
n Put the mixture into wooden or steel mould boxes or
mould machine
n Demould blocks immediately after compaction.

3. Curing
n Cover demoulded blocks with plastic sheets for 24 hours
n Keep the concrete blocks moist by keeping under water
in tanks or by regularly spraying with water for 7 days

4. Storing
n Do not expose to direct sun light keep the blocks in a dry
and covered area
n Store for 2 weeks before usage

Text & Layout by: Skat, Vadianstrasse 42, CH-9000 St.Gallen, Switzerland, phone: +41 71 228 54 54, mail: info@skat.ch, web: www.skat.ch
Curved Concrete Tile
Technical Data
Building element Tile of slab system
Mixing ratio 1 cement : 4 aggregates
Cement used per m3 460 kg
Resistance to earthquakes Very good
Resistance to typhoons Very good
Resistance to rain Very good
Resistance to insects Very good
Climatic suitability All climates
Stage of experience Experimental
Production costs per m2 Rp. 4,000- 5,000 per tile
Durability Approx. 30 years

Short Description Raw Material

n Curved concrete tiles are prefabricated and used in Slab Cement:
Systems n Ordinary Portland Cement
n Tiles are manufactured using high strength concrete
made of an optimised mix of cement, aggregate and Aggregate:
water n Sand or gravel

Size: 30 x 60 x 2cm n Max. particle size of coarser aggregates is 10mm

n Suitable aggregates are usually obtained from natural
sources (river beds, gravel pits, volcanic deposits) or
from industrial by-processes (granulated blast furnace
slag, sintered fly ash)

Cement-Aggregate Ratio:
n Suitable proportion of aggregate to cement must be
found by testing
n Common ratio is 1:4

Water-Cement Ratio:
n Only drinking quality water should be used to mix the
concrete.
Advantages n Recommended water-cement ratio is 0.5

Technical advantages Steel reinforcement:

n High structural strength n U 24, U 39
n No shuttering required
n Rapid construction

Economic advantages
n Production can be started with little capital Equipment
n Less wood is consumed
n Ordinary masonry equipment: spades pans, sieves, trow-
els, sand and cement batching boxes, balance, etc.
n Screeding machine: includes a vibrating surface and a
Limits of Application
hinged frame (MCR vibrating table)
n Skilled labourers required n Testing equipment
Production Process Skills Required
n Prepare the cement mix using cement, aggregates, and n Special training is needed
water (cement-aggregates ratio is 1:4) n Engineer has to calculate reinforcement of beams

Equipment Supplier
ArCli, Banda Aceh

Costs for Equipment

Tile production equipment incl. 100 tile moulds:
n Apply cement on vibrating table and make it plane
Rp. 15,000,000
n Apply and align the wet concrete tile on mould
n Let the freshly cast moulds dry for 24hrs to attain a mini-
mum strength
n Demould the curved tiles
n Stack the tiles and cure them in water for minimum of 7
days

Text & Layout by: Skat, Vadianstrasse 42, CH-9000 St.Gallen, Switzerland, phone: +41 71 228 54 54, mail: info@skat.ch, web: www.skat.ch
 Architecture Clinic

MCR Micro Concrete Roof

Technical Data
Building element Roof
Size 25 x 50 x 1.0 cm
Mixing ratio 1 Cement : 2-3 Aggregates
Cement used per m² 5-7 kg
Weight per m² 37 kg
Resistance to earthquakes Good
Resistance to typhoons Satisfactory
Resistance to rain Good
Resistance to insects Good
Climatic suitability All climates
Stage of experience Mature technology
Production costs per m² Rp. 26,000
Durability 15-20 years

Short Description Limits of Application

Micro Concrete Roofing (MCR) is a roofing technology de- n MCR tiles are used for sloping roofs with minimum incli-
veloped 20 years ago. It consists of concrete tiles made of nation of 20°; (25° in regions with tropical heavy rains or
a cement mortar mix. MCR tiles are produced on a small typhoons)
vibrating table, which can be operated by a single trained n Good quality raw materials are necessary to produce
worker. MCR allows for decentralised and small-scale pro- high quality MCR tiles.
duction.
n An MCR rooftop can not function as an area for gather-
Dimension and shape: ings, drying of cloth or placing aerial antennas, etc.
n In areas where there is no tradition in the use of concrete
roof tiles, extra efforts to boost the product in the market
are necessary.
n If MCR tiles are not painted, fungal and algal growth is
common in tropical humid climates.
n The manufactory of MCR tiles should be located closely
to the reseller’s market (not more than 100 km) in order
to reduce handling and transportation cost.
n Special training is required.

Advantages Raw Material

Technical Advantages Cement: Ordinary Portland Cement; Cement/aggregate
n Good stability and durability, if properly manufactured ratio is 1:3
and installed.
Aggregates consist of:
n MCR tiles are easy to handle.
n In hot climates, houses covered with MCR remain cooler Sand: Angular particles and good grain size distribution be-
compared to metal sheet roofs. tween 0.06 and 2 mm (33%); free from silt and clay.
n MCR tiles are lighter than pressed concrete tiles. Gravel: Mix of grain sizes: 2-4 mm (33%), 4-6 mm (33%);
n MCR tiles are more environmental friendly produced and
Sand/gravel ratio is 1:2
recycled compared to metal sheet roofs.
n MCR can be produced in many different colours. Water: Good quality water (drinkable water); water/cement
ratio is 0.5-0.65 by weight
Economic Advantages
n Locally produced and low-cost Admixtures: Waterproofers are used, if the sand is not
n Labour-intensive well graded, and colorants, if the grey cement colour is not
n Only little investment is needed desired.
Equipment Surface Treatment
n Ordinary masonry equipment: spades pans, wheelbar- n Painting of tiles with elastomeric or rubberised paints for
rows, sieves, trowels, sand and cement batching boxes, a durable fungus-resistant top coat.
balance, etc.
n Fungicidal washes such as sodium silicate, copper sul-
n Screeding machine: includes a vibrating surface and a phate or even household bleaching.
hinged frame.
n Painting needs to be re-applied after some years.
n Setting moulds: made of impact-resistant PVC or fibre
glass, with rib markings (for accurate positioning of the
tile edge) and supporting frame for stacking.
n Testing equipment
Installation of MCR
n MCR tiles are fixed well to the substructure in order not to
be torn off by typhoon or earthquake.
Production Process
n MCR tiles are laid on timber laths or steel angles (spaced
1. Prepare the aggregates (sand, gravel) in ratio 1:2 at 40 cm).
2. Mix cement and aggregates by using shovel, hoe or me- n Fixed with wire loops, nailed or tied onto the timber laths
chanic mixer. Then add sufficient water. or steel angles.
3. Put the wet mix onto the polythene interface sheet on the
screeding machine and, under vibration, smooth with a
trowel to the same level as the surrounding steel frame.

Skills required
Training from well-qualified and experienced resource
persons is a must before an MCR production unit is estab-
4. Lift off the steel frame from the screeding surface. Pull a lished
polythene sheet over the PVC setting mould.

Equipment Supplier
Parry Associates, UK
www.parryassociates.com

Eco Sur, Ecuador

ecosur@ecosur.org

TARA Technology and Action, India

www.devalt.org/TARA/

Appro-Techno, Belgium
www.appro-techno.com

5. Place the mould with the fresh tile on a stack of moulds

for initial setting and curing for 24 hours.
Costs for Equipment
6. Demould tiles afterwards and let them cure for 2 weeks in Vibrating screeding machine, 200 moulds, and accessory
water tanks. pack: Rp. 15,000,000

Text & Layout by: Skat, Vadianstrasse 42, CH-9000 St.Gallen, Switzerland, phone: +41 71 228 54 54, mail: info@skat.ch, web: www.skat.ch
Paving Blocks
Technical Data
Building element Yards, sidewalks
Size Various sizes
Mixing ratio 1 cement : 8-10 aggregate
Cement used per m3 250-300kg
Resistance to earthquakes Very good
Resistance to typhoons Very good
Resistance to rain Very good
Resistance to insects Very good
Climatic suitability All climates
Stage of experience Widely used method
2
Production costs per m Rp. 50,000
Durability Approx. 30 years

Short Description Raw Material

Paving blocks are prefabricated in many shapes and sizes. Cement:
They are made of cement, aggregates and water. n Ordinary Portland Cement

They can be used for home yard floors, sidewalks or roads

Aggregate:
because of their high resistance to rain and heavy weather.
n Sand and gravel
Size and shape are variable. n Max. particle size of coarser aggregates is 10mm
n Suitable aggregates are usually obtained from natural
sources (river beds, gravel pits, volcanic deposits) or
Advantages from industrial by-processes (granulated blast furnace
slag, sintered fly ash)
Technical advantages
Cement-Aggregate Ratio:
n Easy to produce
n Common ratios are 1:8, 1:10
n High compressive strength, resistance to weathering,
impact and abrasion n Test the quality of blocks produced
n Capability of being moulded into components of any
shape and size Water-Cement Ratio:
n Only drinking quality water should be used to mix the
n Rapid laying
concrete.
n Very good stability
n Recommended water-cement ratio is 0.35 - 0.45
Economic advantages
n Production can be started with little capital.
n Time and cost efficient to produce
n Time and cost efficient to install Equipment
n Masonry tools
n Mixers: Pan mixers; Trough mixers
Limits of Application
n Moulding machine
n Relatively large quantity of raw material is needed
n Moulds
n If paved area is used for vehicles, special preparation of
the ground is needed
 4. Storing:
Production Process
n Do not expose to direct sun light; keep the blocks in a dry
1. Batching and mixing: and covered area
n Batch aggregates and cement by weight n Store for 2 weeks before usage
n Mix cement and aggregates using mattock, shovel or
mixer until it reaches homogeneous condition

Skills Required
n Concrete making and masonry skills
n Semi-skilled labour

n Add some water

Costs for Equipment
n Manual press machine Rp. ####
n Semi automatic press machine Rp. ####
n Mould Rp. ####

n In hot climates, the fresh mix must be shaded from the Equipment Supplier
sun
Parry Associates, UK
2. Moulding: www.parryassociates.com

n Put the mixture into wooden or steel mould boxes or TARA Technology and Action, India
moulding machine www.devalt.org/TARA/
n Demould blocks immediately after compaction
Appro-Techno, Belgium
3. Curing: www.appro-techno.com
n Cover demoulded blocks with plastic sheets for 24hrs Local suppliers
n Keep the concrete blocks moist by keeping under water
in tanks or by regularly spraying with water for 7 days

Blocks cured in water tank

Text & Layout by: Skat, Vadianstrasse 42, CH-9000 St.Gallen, Switzerland, phone: +41 71 228 54 54, mail: info@skat.ch, web: www.skat.ch
Beam Block
Technical Data
Building element Wall

Size 14,5 x 29 x 14cm

(width x length x height)
Mixing ratio 1 cement : 6-8 aggregates
3
Cement used per m 250-300kg
Resistance to earthquakes Very good
Resistance to typhoons Very good
Resistance to rain Very good
Resistance to insects Very good
Climatic suitability All climates
Stage of experience Widely used method
Production costs per m Rp. 7,500
Durability Approx. 30 years

Short Description Limits of Application

Beam Blocks (u-shaped) are used for reinforced ground n Raw materials must be locally available, of good quality
beams, lintels, and ring beams. The usage of Frame Block and economically viable
minimises wood consumption because formwork is no more n Relatively large amount of cement is needed, which can
necessary. be expensive and difficult to obtain
n Special knowledge and experience of the production
process is needed

Raw Material
Cement:
n Ordinary Portland Cement

Aggregates:
Advantages
n Sand and gravel
Technical Advantages n Max. particle size of coarser aggregates is 10mm
n Very good stability n Suitable aggregates are usually obtained from natural
n For strong and light walls sources (river beds, gravel pits, volcanic deposits) or
from industrial by-processes (granulated blast furnace
n Rapid construction
slag, sintered fly ash)
n Voids can be filled with steel bars and concrete
Cement-Aggregate Ratio:
n Are lighter in weight than solid blocks
n Suitable proportion of aggregate to cement must be
n The cavity provides good thermal insulation
found by testing
Economic Advantages n Common ratios are 1:6, 1:8
n Production can be started with little capital
Water-Cement Ratio:
n Less working time required for brick laying work with
n Only drinking quality water should be used to mix the
concrete blocks
concrete
n Less mortar consumption
n Recommended water-cement ratio is 0.5
n Generally, production costs of Frame blocks are slightly
lower than of fired bricks
Equipment Skills Required
n Blockmaking equipment n Concrete making and masonry skills
n Masonry tools n Special training at ArCli is recommended
n Manual moulds

Production Process Costs for Equipment

1. Batching and mixing: n Manual press machine Rp. ####

n Batch aggregates and cement by weight n Semi automatic press machine Rp. ####
n Mould beam block Rp. ####
n Mix cement and aggregates using mattock, shovel or
mixer until it reaches homogeneous condition

Equipment Supplier
Parry Associates, UK
www.parryassociates.com

TARA Technology and Action, India

www.devalt.org/TARA/

ArCli, Banda Aceh

n Add some water Local suppliers

n In hot climates, the fresh mix must be shaded from the

sun

2. Moulding:
n Put the mixture into wooden or steel mould boxes or
moulding machine
n Demould blocks immediately after compaction

3. Curing:
n Cover demoulded blocks with plastic sheets for 24hrs

n Keep the concrete blocks moist by keeping under water

in tanks or by regularly spraying with water for 7 days

4. Storing:
n Do not expose to direct sun light; keep the blocks in a dry
and covered area
n Store for 2 weeks before usage

Text & Layout by: Skat, Vadianstrasse 42, CH-9000 St.Gallen, Switzerland, phone: +41 71 228 54 54, mail: info@skat.ch, web: www.skat.ch
Concrete Door & Window Frames
Technical Data
Building element Door and window frame
Size Various sizes
Mixing ratio 1 cement : 4 aggregates
Cement used per m3 460 kg
Resistance to earthquakes Very good
Resistance to typhoons Very good
Resistance to rain Very good
Resistance to insects Very good
Climatic suitability All climates
Stage of experience Commonly used
Production costs Please fill in!
Durability 50 years

Short Description Raw Material

Concrete doors and windows frames are an attractive alter- Cement:
native to wooden frames where there is scarce wood. And it n Ordinary Portland Cement
can help to save wood and therefore to protect natural forest
n Special cements
resources.
Aggregate:
Advantages n Sand and gravel, max. particle size of coarser aggre-
gates is 6mm
Technical Advantages n Suitable aggregates are usually obtained from natural
n Good weather resistance sources (river beds, gravel pits, volcanic deposits) or
from industrial by-processes (granulated blast furnace
n High structural strength
slag, sintered fly ash)
n Fast construction
n Easy installation Cement-Aggregate Ratio:
n Flexible in use n Suitable proportion of aggregate to cement must be
found by testing
n Frames can be adjusted to the building design
n Common ratio is 1:4
n Easy maintenance
n Good fire resistance up to 500°C Water-Cement Ratio:
n Only drinking quality water should be used to mix the
Economic Advantages concrete.
n Savings in working time through fast construction
n Recommended water-cement ratio is 0.45
n Cost-efficient and durable compared to wooden frames
n Steel reinforcement
(up to 50% saving)

Limits of Application Equipment

n Raw materials must be locally available, of good quality n Masonry tools
and economically viable n Mixers: Pan mixers; Trough mixers
n Special knowledge and experience of the production
n Frame moulds
process is needed
n Formwork/moulds must be accurate and of very good
quality, preferably made of steel
n Regular quality control is a must
n Fixing of hinges and locks require special skills
n Doors and window shutters must match with frames
Production Process
1. Batching and mixing:
n Batch aggregates and cement by weight
n Mix cement and aggregates using mattock, shovel or
mixer until it reaches homogeneous condition

n Add some water

Equipment Supplier
TARA Technology and Action, India
www.devalt.org/TARA/

bmtpc, India
www.bmtpc.org/machines/CC-1.htm
n In hot climates, the fresh mix must be shaded from the
sun Local suppliers

2. Moulding:
n Put the mixture into moulds
Costs for Equipment
n Let dry for min. 7 days
n Frame mould: 50-100 USD
n Demould frames
Optional:
3. Curing:
n Frame Moulding machine: ca. 1,000 USD
n Keep the concrete frames moist by keeping under water
n Mixer machine: ca. 1,200 USD
in tanks or by regularly spraying with water for 7 days

4. Storing:
n Do not expose to direct sun light; keep the frames in a dry
and covered area
Skills Required
n Store for 2 weeks before use Special training is needed

Text & Layout by: Skat, Vadianstrasse 42, CH-9000 St.Gallen, Switzerland, phone: +41 71 228 54 54, mail: info@skat.ch, web: www.skat.ch
CEB Compressed Earth Block

Technical Data
Building element Wall
Size Various sizes
Mixing ratio Cement/soil 1:5-10
3
Weight per m 1,7-2,2t
Resistance to earthquakes Good
Resistance to typhoons Good
Resistance to rain Good
Resistance to insects Good

Climatic suitability Suitable for all climates,

except very wet climates
Stage of experience Used in many countries
Production costs per m3 Please fill in!
Durability 50 years

Economic Advantages
Short Description
n Lower production cost and energy input compared with
To produce Compressed Earth Blocks (CEB), soil (raw or fired bricks
stabilised) is slightly moistened, poured into a steel press, n Locally produced (less transportation costs)
and then compressed. n Flexible production size unit (from small scale workshop
to large scale plant)
The usage of stabilisers allows building higher and thinner
n Labour intensive. Creates jobs.
walls, which have a much better compressive strength and
water resistance. n Saves on wood consumption. No wood is required.
n Profitable business if well managed
Various sizes and shapes can be produced.

A common size of CEBs in Indonesia is 22x10x8cm.

Limits of Application
n Lack of good soil
n Lack of good equipment
n Cannot be used for big loads or in high rise buildings
n Cannot be used underwater or in continuously wet condi-
tions

Advantages Raw Material

n Environmental-friendly technology n Suitable soil with a good grain size distribution and a clay
content of 10-25%
n Stabiliser (cement, lime)
n Waterproofing agents are optional

Equipment
n Block press (manually or mo-
torised operated)
n Masonry tools (sieve, crusher,
Technical Advantages wheelbarrows, mixer, basic
n Good stability and strength tools, PVC sheets, etc.)
n Thermal insulation n Quality control devices
n Very regular in size and shape
n CEBs can be produced in various shapes and sizes.
n Easy transportation of dried blocks
 Curing of the blocks:
Production Process
n Stack the CEBs
Preparation of the soil:
n Select soil with good grain size distribution and good
cohesive performances

n Keep the CEBs moist

n Pulverise the raw material and sieve out clay lumps, n Cure for 4 weeks
gravel and stones
n A hot and humid atmosphere gives best results
n Do not expose to sun and rain

Equipment Supplier
Development Alternatives, Delhi- India
Email: tara@devalt.org
n Mix the prepared soil with the stabiliser
Auroville Earth Institute
Auroshilpam, Auroville- India
Email: earth-institute@auroville.org.in

Parry Associates, UK
www.parryassociates.com

Fernco Metal Products

n Moisten the mix with water Email: fernco@ferncometal.com

Costs for Equipment

n Hand operated press machine costs ca. 900-1,200 USD
n Air/hydraulically operated press is ca. 1,800 USD

Compression of the mixture: Skills required

n Pour into a steel press Special training is needed

n Compress manually or motorised

Text & Layout by: Skat, Vadianstrasse 42, CH-9000 St.Gallen, Switzerland, phone: +41 71 228 54 54, mail: info@skat.ch, web: www.skat.ch
Well Ring
Technical Data
Building element Well Ring
Size Variable
Weight per unit 125 kg (size: 90 x 30cm)
Mixing ratio 1 cement : 8 aggregates
3
Cement used per m 300 kg
Resistance to earthquakes Very good
Resistance to typhoons Very good
Resistance to water Very good
Resistance to insects Very good
Climatic suitability All climates
Stage of experience Widely used method
Production costs per unit Rp. 80,000
Durability Approx. 30 years

Short Description Limits of Application

Well ring units are used to build wells, water tanks, latrines, n Not recommended for overhead water tanks
and culverts. n Raw materials must be locally available of good quality
and economically viable
Ring wells can be also used as supporting rings during the
building of foundations. Well rings hold the surrounding soil n Special formwork of steel or wood is required
and prevent it from collapsing during the casting of founda-
tions.
Well rings can be produced in many sizes and shapes. The
most common size is:
Outer Diameter: 90 cm
Raw Material
Inboard Diameter: 80 cm
Height: 35 cm
Cement
n Ordinary Portland Cement

Aggregates
n Sand and gravel
n Max. particle size of coarser aggregates is 10 mm
n Suitable aggregates are usually obtained from natural
sources (river beds, gravel pits, volcanic deposits) or
from industrial by-processes (granulated blast furnace
Advantages slag, sintered fly ash)
Technical Advantages Cement – Aggregate Ratio
•n Can be produced in various shapes and sizes n Proportion of aggregate to cement can be optimized
n High compressive strength through testing
n Resistance to soil acids, impact and abrasion n Common ratio is 1: 8 (cement: aggregates)
n Very good stability
Water-Cement Ratio
n Easy to produce
•n Only drinking quality water should be used to mix the
n Rapid construction concrete
Economic Advantages n Recommended water-cement ratio is 0.5
n Production can be started with little capital
•n Can be mass produced
n Is an attractive business for small-scale enterprises
Equipment Skills Required
n Mixers: Pan Mixers, n Concrete making and masonry skills
Trough mixers
n Manual moulds
•n Masonry tools
n Steel formwork
Equipment Supplier
n Steel or wooden formwork can be produced locally

Production Process Costs for Equipment

1. Batching and mixing •n Steel formwork: Rp. #####
n Batch aggregates and cement by weight n Wooden formwork: Rp. #####
n Mix cement and aggregates using mattock, shovel or
mixer until it reaches homogeneous condition

n Add some water

n In hot climates, the fresh mix must be shaded from the

sun

2. Moulding
n Put the mixture into wooden or steel mould (round tun
shaped)
n Let dry for min. 7 days
n Demould well rings

3. Curing
n Keep the well rings moist by keeping under water in large
tanks or by regularly spraying with water for 7 days.

4. Storing
n Do not expose to direct sun light and rain
n Store for 2 weeks before usage

Text & Layout by: Skat, Vadianstrasse 42, CH-9000 St.Gallen, Switzerland, phone: +41 71 228 54 54, mail: info@skat.ch, web: www.skat.ch
Rubble Stone Masonry Foundation
Technical Data
Building element Foundation
Size Width: 30-40cm
Heigth: 80-150cm
Mixing ratio -
Cement used per m3 -
Weight per m3 -
Resistance to earthquakes Good
Resistance to typhoons Good
Resistance to rain Good
Resistance to insects Good
Climatic suitability All climates
Stage of experience Widely used
Production costs per m3 Rp. 500,000
Durability 50 years

Short Description Limits of Application

Stone foundations are made of rubble stone. A similar n Construction should start on firm, uniform, and strong
construction is possible with concrete from demolished subsoil
buildings. n Do not construct on grass, black fertile soil, filled up ma-
terials, or mud
The quality of mortar is of high importance to achieve good
n In earthquake areas, reinforcement with wire mesh or
strength.
steel rods is required; professional advice should be
Suitable size of stones is 10-25cm. sought

Raw Material

Stone:
n Cleaned rubble stone stone, or concrete pieces

Mortar:
n Made of cement, sand, and water
n The recommended ratio for cement/sand is 1:4
n The recommended water-cement ratio is 0.5

Advantages Equipment
Technical advantages n Ordinary masonry tools
n Good stability
n Long lasting
n Raw materials are locally available and easy to trans-
port
n Easy to be processed by semi-skilled labourers

Economic advantages
n Cost efficient to construct
n Generally, material costs are lower than of concrete foun-
dations
n Processing can be started with little capital
Production Process
n Prepare foundation trenches in the soil (min. depth
40cm)
n Apply a layer of lean concrete (min. 5cm) or tramped
sand
n Mount carefully the stones in required width and height
n Keep joints as narrow as possible
n Fill all cavities well with mortar
n Refill foundation trenches
n Compact the refilling

Skills Required
n Masonry skills
n Semi-skilled labour

Costs for Equipment

No special equipment required

Equipment Supplier
No special equipment required

Text & Layout by: Skat, Vadianstrasse 42, CH-9000 St.Gallen, Switzerland, phone: +41 71 228 54 54, mail: info@skat.ch, web: www.skat.ch
Prefabricated Concrete Footings
Technical Data
Building element Foundation
Size As per engineer’s calculation
Mixing ratio 1 cement : 4 aggregates
Cement used per m3 Equivalent to P 350 (in CH)
3
Weight per m 2,3 t
Resistance to earthquakes Very good
Resistance to typhoons Very good
Resistance to rain Very good
Resistance to insects Very good
Climatic suitability All climates
Stage of experience Commonly used
Production costs per m3 Please fill in!
Durability Approx. 50 years

Short Description Limits of Application

Prefabricated concrete footings are a solid and durable al- n Size and required reinforcement should be calculated by
ternative to rubble stone masonry foundations. an engineer
n Raw materials must be locally available, of good quality
Concrete footings have a very good resistance to earth-
and economically viable.
quakes and can be used in various types of grounds and
n Special knowledge and experience of the production and
soils.
installation process is needed.
n The bottom of foundation has to be well prepared with a
soling and neat for the placement of the footings

Advantages
Technical advantages
n High compressive strength, resistance to weathering,
impact and abrasion
n Lifting equipment is required
n Capability of being moulded into components of any
shape and size according to the type and pressure of the
planned building, and the type of soil Raw Material
n Rapid construction
Cement:
n Very good stability
n Ordinary Portland Cement
n Long lasting n Special cements

Economic advantages Aggregate:

n Production can be started with little capital n Sand and gravel

n Time and cost efficient to produce Cement-Aggregate Ratio:

n Time and cost efficient to install n Suitable proportion of aggregate to cement must be
n In good soils and non-earthquake zones, footings can be found by testing
made without reinforcement n Common ratio is 1:4
Water-Cement Ratio: 3. Curing:
n Only drinking quality water should be used to mix the n Cover demoulded footings with plastic sheets for 24hrs
concrete. n Keep the concrete footings moist by keeping under water
n Recommended water-cement ratio is 0.5 in large tanks or by regularly spraying with water for 7
days
Reinforcement
n Steel bars of 12-16mm diameter, as per engineer’s cal- 4. Storing:
culation n Do not expose to direct sun light; keep the footings in a
dry and covered area
n Store for 2 weeks before use
Equipment
n Ordinary masonry equipment: spades pans, sieves, trow-
Costs for Equipment
els, sand and cement batching boxes, balance, etc.
n Mixers: Pan mixers; Trough mixers Has to be requested from ArCli, Banda Aceh
n Moulds
n Reinforced concrete making equipment (spacers, steel
cutter)
Equipment Supplier
n Lifting equipment No special equipment needed

Production Process Skills Required

1. Batching and mixing: n Concrete making and masonry skills
n Batch aggregates and cement by weight n Skilled labour

n Prepare the cement mix using cement, aggregates, and

water
n In hot climates, the fresh mix must be shaded from the
sun

2. Moulding:
n Prepare molds/formwork Vertical section
n Place the steel bars and necessary brackets in the
moulds

n Fill the cement mix into prepared moulds

n Demould footings immediately after compaction Horizontal section

Text & Layout by: Skat, Vadianstrasse 42, CH-9000 St.Gallen, Switzerland, phone: +41 71 228 54 54, mail: info@skat.ch, web: www.skat.ch
 Architecture Clinic

Wooden Roof Truss

Technical Data
Building element Roof structure
Size -
Mixing ratio -
Cement used per m3 -
3
Weight per m -
Resistance to earthquakes Good
Resistance to typhoons Good
Resistance to rain -
Resistance to insects Needs protection treatment
Climatic suitability All climates
Stage of experience Commonly used
Production costs per m3 Please fill in!
Durability 50 years

Economic advantages
Short Description
n Economic use of timber
The wooden roof truss system is used as roof sub-construc- n Mass production of trusses economises in production
tion. Different types of roof coverings can be combined with costs
it. n Advantage in transport and assembly compared to con-
ventional roof structures
The wooden roof truss is a structure with straight members
forming triangles to support a load. The pieces of the trian- n Relatively small profiles required
gles are placed under tension and compression, but must
not bend.
Roof trusses can be made for flat, single and double pitched
roofs. Limits of Application
Joints of wooden roof trusses can be made with nails, bolts n Requires Engineer’s calculation or use of Roof Truss
or plate connectors Guide
Spans of nail trusses can vary from 6- 20m. n Timber must have good resistance against rot, insects
and fungal attack
n Timber must be protected fully against weather impacts

Raw Material
n Timber of good quality and well dried
n Nails (min. tensile strength 600 N/mm²) or screws, or
bolts
n Plate connectors

Advantages Equipment
Technical advantages n Carpenters tools
n Good stability
n Light weighted
n Suitable for construction in remote areas and at sites
without lifting equipment. Can be handled manually.
Production Process Skills Required
Wooden roof trusses can be prefabricated or in situ as- Good carpentry skills
sembled.
n Prepare a template by drawing the dimensions of the
truss on a flat surface Costs for Equipment
n Cut the truss members and assemble them according to
the template No special equipment required
n Prepare template for the nail fixing at the ends of the
truss pieces
n Connect the timber pieces using nails, bolts or plates Equipment Supplier
Local suppliers
Installation
n Trusses must be fixed properly to the supporting ring
beam or column
n Wooden roof trusses need a carefully fixed bracing
against wind forces
n Distance between the trusses depends on size of purlin
and weight of roofing materials

Text & Layout by: Skat, Vadianstrasse 42, CH-9000 St.Gallen, Switzerland, phone: +41 71 228 54 54, mail: info@skat.ch, web: www.skat.ch