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Steel Days Scoping Study


November 2011, Luxembourg This booklet was produced in the context of the Steel Days Conference, organised by the IFRC Shelter Research Unit in November 2011with the purpose to open up the debate on the use of steel for humanitarian sheltering.

The scoping study is the outcome of a short term research project looking into the variety of steel options that are or could be pertinent for humanitarian sheltering, documenting implemented sheltering projects making use of steel and other interesting examples, and, thridly, highlighting references that could substantiate a discussion around steel for sheltering. This research was conducted by an independent researcher, Carmela Mayrink Martins. Luxembourg, November 2011 IFRC Shelter Research Unit 44, bd Joseph II – L – 1840 Luxembourg Cover Photographs by Jonas Bendiksen


Introduction


Humanitarian Sheltering

“Shelter is critical to survival. From the emergency phase until durable solutions, it is necessary to provide security and personal safety, while protection from the climate also protects from ill health and disease. Shelter and settlement support human dignity and family and community life, when populations are displaced or in their homes, maximizing communal coping strategies� (The Sphere Project, 2004). The physical space around us, our houses and settlements, are at the heart of the functioning of our families and communities. When a disaster hits, we don’t just lose our house, but we lose a place where to feel home, where to eat with our families, where to invite people to, where children can make their homework and feel safe. Moreover, the house often takes a crucial place in the household economy: as an investment and/or as a place to be productive. Humanitarian sheltering therefore is not easy: any solution needs to take into account how sheltering is strongly interlinked with all other aspects of life.

Logistics: Steel provides transport solutions that respond quickly, efficiently and economically. Food: Steel is part of every step of our food supply network; cultivation, manufacture, preservation and delivery. Water: Steel is involved in the process of water collection, management, purification and delivery. Health: Steel is in the hospitals we rely on, the pharmaceutical systems that manufacture our medicines, and in emergency equipment that gives medical assistance in rapid response. Livelihoods: Agriculture is vital to reestablish the population affected by catastrophes. It provides them food, clothing and livelihoods.

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Steel is the general name given to a large family of alloys of iron with carbon and a variety of other elements that can have dramatic effects on its properties. The amount of carbon it contains is crucial, most carbon steel has a carbon content of less than 1%. Carbon is the principle hardening element of steel. (European norm NEN-EN 10020 – Definition and classification of steel)

Humanity’s need for housing is great and growing, and innovative steel solutions can help meeting humanity’s need for shelter. Steel is long-lasting, versatile and 100% recyclable.

Steel

Among the steel types it is low carbon steel that is used extensively for roof sheets, structural steel and concrete reinforcement. It has up to 0.25% of carbon in its alloy, and is easy to assemble with all kinds of fasteners and techniques, it is malleable and ductile. Different mechanical and heat treatment can influence the properties of different steel products.

Photograph by Joseph Ashmore

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Scoping Study

Steel has not often been the object of study in the humanitarian sheltering world. Steel is however being used more and more. In more contexts, the local construction industry is accustomed to using steel in housing, which also allows the disaster affected population to carry more of their own response and recovery efforts. Steel has clear benefits, as its versatility, strength and the fact that it can be recycled. Both complete steel constructions as steel used in combination with other materials are becoming current practice in humanitarian sheltering, but there is scope for improvement. This scoping study is an attempt of the IFRC SRU to lay open the use of steel in humanitarian sheltering: presenting the current practice and discussing it, to open the way for improvements and innovation. We collected as much as we could and thought relevant for the discussion, we sorted, compared and commented. This scoping study is a stimulator for exchange, it is a draft that attempts to set a base line.

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Cases & Examples – Techniques – Reference Materials Building on no prior body of concerted knowledge on sheltering using steel, we set out to collect all we could using the net, and a few professional connections. To construct a starting point, we collected mainly three types of information: Implemented sheltering projects, examples of technologies, or partial projects Technical information on elements of steel in construction relevant to the construction of shelters Reference materials: websites, books, forums It is important to note that inclusion in this booklet does by no means mean that these are ‘approved’ solutions, or ‘recommended by the IFRC SRU’. The only criteria we used to decide on inclusion or not was: -Whether the technique or example is or could become relevant for humanitarian sheltering -Can the technique or example add constructively to the discussion and the formulation and development of improvements and innovation.

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« High tech versus low tech » & « temporary versus permanent » We proceeded by classifying and qualifying the information, giving further insight into how humanitarian sheltering uses and could use the techniques and examples presented in the booklet. You will quickly notice that, according to current day steel construction, nothing in this booklet is truly high tech. This classification however helps us to understand which technologies can be used in which contexts and in which phases of the disaster response. The three star rating, in comparison to the one star rating, indicates that the discussed example or item would require a greater financial input, more technical guidance or professional construction skill, better quality material and more time, but is likely to create a higher structural quality and hazard resistance. The one star rating can therefore, for example, more easily be seen used in shelter kit distributions to a large number of people with lesser technical or skilled input. Also temporary and permanent hardly exist in humanitarian sheltering. This distinction highlights that most shelters evolve in time; because construction takes time and it is a process of recovering and reconstructing rather than the immediate restitution of the lost or damaged physical structure present before disaster. Some products may thus be suitable for an immediate response sheltering people for a couple of weeks/ months, whereas other offer a more durable solutions. Notes are added all through the document . Sometimes they try to clarify the star rating attributed, on other occasions they highlight some crucial aspects qualifying the presented as a good or less good solution for sheltering.

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Many approaches to increase the resistance of, repair or rebuild houses can be applied throughout the disaster management cycle and don’t need to be pinned down to one phase. More and more the humanitarian world strives to increase the resilience of communities to reduce the impact of disasters. This booklet can be expanded and adjusted a lot, we are aware of that. It needs to be reviewed by a greater group, and enriched with many more implemented projects and a greater precision. The conference will be used as an occasion for that. In terms of examples and cases, we’ve basically included everything we could find through a simple network search and mailing a few professionals. Also therefore this review is important, to ensure that all is referenced as it should be and gets the presentation it deserves. Missing things are for example tools for steel construction, reflections on the process of construction and skills required, or engineering calculations necessary. Technologies, examples, project, and references: all the elements of an emerging reflection are here, they just needs to be elaborated. Booklet

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Shelter Designs and Examples

1 _ Wire mesh planned & unplanned …

a _ Sri Lanka - 2004 - Tsunami..................

13

b _ Somalia - 2009 - Conflict / Drought.......

14

c _ Vietnam – 2004 – Flood and Typhoons. d _ Haiti - 2010 - Earthquake....................... e _ Haiti - 2010 - Earthquake.......................

15 18 19

f _ Bangladesh - 2007 - Cyclone Sidr.........

20

g _ Indonesia – 2005 - Tsunami...................

21

h _ Haiti - 2010 - Earthquake......................

24

i _ Haiti - 2010 - Earthquake........................

27

j _ Thailand - 2006 - Tsunami......................

28

k _ Indonesia – 2004 - Tsunami..................

29

2 _ Wire and cables – E.S. Peru………… 42 3 _ Rebar – retro-fitting Bangladesh........ 44

4 _ Panels - MiiHome System................... 5 _ Panels _ UK 1945 post conflict…….. 6 _ Panels – Protea System..................... 7 _Profiles - Prototype...............................

46

9 _Profiles – TransHome........................... 10 _Profiles – Losberger...........................

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61 8 _Profiles – Family tent............................ 62

64

11 _ Profiles _ Reciproboo ....................... 66

12 _ Trusses _ Afghanistan....................... 67

13 _ Foundation - Phillipines .................... 73 14 _ Foundation - Central Vietnam............. 75 15 _ Foundation - South Vietnam................ 77

16 _ Foundation - Bangladesh................... Booklet

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Te c h n i q u e s A _ Items

29

Connectors.............................. Wires, cables, meshes, rods... Fasteners.................................

30 36 43

49

B _ Sheets and Panels Roofs and Walls...................... Panels.....................................

50 54

C _ Frames

59

Profiles..................................... Trusses....................................

60 65

Anchor, plates, boxes, screws..

92

2 _ Books and product info for the booklet 3 _ Websites for the booklet…………….

93

70

81

E _ Other Aspects Environment……………………… Climate Design…………….……... Aluminum……………………………

99 100

References

82 84 89

Booklet

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4 _ Other relevant websites................. 5 _ Selection of general shelter literature

69

D _ Foundation

1 _ Video sources for the booklet……………

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Only the technical aspects of these shelter designs are presented. It is however crucial to consider for each of these designs in which sheltering process it fits.

Shelter Designs

Design in humanitarian sheltering thus has a specific role: it’s giving shape not only to a space, not only to a dwelling to live is, but to a process of recovering from disaster as well. Some of these designs have been built in large numbers after a disaster. Others were prototyped in the field but never actually used in disaster responses.

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a. Sri Lanka - 2004 - Tsunami This is a transitional shelter design and has a 20,5m² area with enclosable veranda space. The structure was made from box-bar metal frame, that could be quickly and easily assembled for even those with little physical strength or no prior construction skills. The metal frame also permits that the shelters can be relocated and reused. The roofs were made from galvanized metal, with open eaves under the roofs to provide ventilation. A veranda was later added as an upgrade and can be used either as an additional living space or as a kitchen area. Sri Lanka Booklet

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b. Somalia – 2009 – Conflict / drought

These shelters have a 16m² area, and were constructed in two temporary settlements by low income families. This model has been based on shelters observed across Hargeisa, and was constructed using imported timber frame and corrugated iron roof and walls. They were executed with simple post foundations that can be easily dismantled and removed at any time, with easy transport components in case of relocation. Most families appeared to have upgraded the shelters.

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• • • • • • • •

IFRC 8 Shelter Designs

c. Vietnam – 2004 – Flood and Typhoons Materials: Galvanized steel frame and Zincalume corrugated roof sheeting Material source: Concrete, blocks, plywood and roofing: sourced locally. Steel frame: procured nationally. Time to build: 3 days Antecipated lifespan: 5 years Construction team: 6 people Number built: 215 Approximate material cost per shelter: Unkown Approximate cost per shelter: 1500 CHF

This shelter is an adequate design for low seismic areas but does not perform well under wind loading. The framing is relatively complex and has been adapted from previous designs. It is very tall which provides the opportunity to include a mezzanine level or raised floor; although the frame would have to be strengthened structurally to support these elements. The frame is made from very thin sections not typically used in construction and the stability relies on the continuity of elements as a moment frame rather than bracing. Its performance could be greatly improved by improving the foundations, the steel members and bracing the walls and roof. Vietnam IFRC 8 shelter designs

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IFRC 8 Shelter Designs

Ground Floor Plan

Roof Level Plan

Section X-X

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IFRC 8 Shelter Designs

Durability and lifespan In many cases the shelters have been upgraded and extended using salvaged and recycled materials. The shelters were designed to be demountable and reusable in other locations. As the cold formed steel sections are extremely thin they are susceptible to corrosion, especially in salty environments, and the durability of the shelter is therefore rather poor. Constructive aspects and upgrades This shelter is lightweight, and a has covered area of 3,6x8,4m on plan. The height of the roof varies from 3.2m at the eaves to 4.6m at the ridge. There are 12 columns, 6 of which have screwed-in-ground anchor foundations, connected in pairs by a braced truss to form a moment frame. The stability system is formed by these 3 moment fames tied together by two further moment frames on each edge of the building. The shelter has a 100mm thick concrete slab base and there is a low, non-structural, 0.5m brickwork wall providing a degree of flood protection. Upgrading the roof or walls with materials of similar weight would not change the structural performance of the shelter providing all cladding materials are adequately fixed to prevent damage under winds loads. Upgrading the roofs and walls with heavier materials, would mean that member sizes would need to be increased and connections and foundation capacities checked. Booklet

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d. Haiti - 2010 - Earthquake This shelter frame is completely made of steel, and each part as walls and roof, was assembled separately next to the site in work stations. Each element was screwed and has diagonal profiles to brace the side. After the first stage, the pieces was transported to the site and assembled together there. The final wall was made on site. After the frame structure was ready, the set was wrapped in tarpaulin. Then the metal mesh was added on top of the tarpaulin, and lastly, a layer of cement was added to the metal mesh to complete the solid structure.

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e. Haiti - 2010 - Earthquake This shelter is a transitional shelter model that can be modified using a range of finishes combined with the steel frame, after the emergency stage. The profile used to assemble the structure is a tubular steel frame 2" x 2" dimension, for both roof and wall. It’s simple to assemble, and can be bolted together eliminating the need of electric tools. Three lacquers were applied allowing for the salt spray life and rust protection. In Haiti at first these shelters were covered with tarpaulins. After the first stage, the walls were changed to a more durable solution, using masonry. The shelter has a 17,86m² area.

Developed by Versatube

Haiti

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f. Bangladesh - 2007 – Cyclone Sidr These shelters have 15m² area core designed to withstand tropical storms and cyclones. The roof structure is made of prefabricated welded steel roof trusses overlaid with corrugated galvanized iron sheets. The cores were expanded upon by the inhabitants itself, the walls were replaced by reused corrugated galvanized iron sheets. The structures were built upon a raised clay and mud-hardened foundation (plinth) with reinforced concrete columns with a Tshaped foot to strengthen and stabilize the foundation. This core shelter solution offers a strong core structure to protect against severe weather. This program trained the families to expand upon the structure, and maintain it, using simple improved local techniques. Bangladesh Booklet

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g. Indonesia – 2005 - Tsunami

• • • • • • •

Materials: Galvanized steel frame, steel sheet roofing, Radiata Pine/Douglas Fir or equivalent treated timber planks, steel foundation plates and anchors, door fixtures, nails, bolts and screws. Material source: Steel frames were manufactured regionally. The roof sheeting and timber imported internationally. Time to build: 1 day to construct the frame. 2 days minimum to clad the shelter. Antecipated lifespan: Minimum 5 years Construction team: 4-5 people Number built: 20.000 Approximate material cost per shelter: 4.765 CHF (2004) Approximate cost per shelter: 5100 CHF (2004)

IFRC 8 Shelter Designs

This shelter «kit» presents a good design solution that is appropriate in areas vulnerable to high seismic loading although minor alterations are required for wind loads. Ensuring that timber planks are nailed to create a diaphragm or substituting them for plywood panels, strengthened columns and upgraded foundation details would improve its performance significantly. It provides a transitional shelter option that is good quality, quickly scalable, and can be re-used or re-cycled. However, it is comparatively expensive and there may be delays due to importation of materials. The design is similar to that of vernacular housing, with the steel replacing the traditionally used timber for the framing material. Indonesia IFRC 8 shelter designs

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IFRC 8 Shelter Designs

Ground Floor Plan Roof Level Plan

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IFRC 8 Shelter Designs

Durability and lifespan The shelter frame, tools, timber planks and studs were delivered as a “kit”. The timber planks and studs were delivered to site pre-cut and treated. The plywood was supplied separately. Windows and gable materials were not provided in the kit to encourage local markets. The shelter “kit” was designed to be demountable and easy to relocate. The durability of the shelter is good since the steel members are galvanized and the timber is treated. Constructive aspects and upgrades The structure consists of a cold rolled, hot dip galvanized steel frame with pitched roof of 24.3 degrees and raised floor. The height is 4.15m to the ridge, and the platform area of the shelter is 25m2 with a cantilevering balcony. There are 6 columns fixed using column base plates nailed directly into the ground. In many cases the shelter has been upgraded by adding porches, partitions and extensions. The performance of this shelter would be significantly improved for a relatively small cost by providing intermediate studs, nailed plywood shear walls and roof bracing. If the shelter is adequately braced, the foundations modified and the column sizes increased, the roofs or walls of the shelter can be upgraded with materials of a similar weight to those already in use. Upgrading the shelter with heavier materials will require appropriate foundation upgrades, and are not recommended, mainly with very heavy materials as masonry. Booklet

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• • • • • • • •

IFRC 8 Shelter Designs

h. Haiti – 2010 - Earthquake Materials: Galvanized steel frame, timber studs, plastic sheeting walls, corrugated steel roof sheeting, concrete foundations, bolts, screws and nails. Material source: Steel frame: imported from Spain, Other materials: sourced locally. Time to build: 2 days Antecipated lifespan: 2 years Construction team: Unknown Number built: 5.100 Approximate material cost per shelter: 1700 CHF Approximate cost per shelter: 4300 CHF

This imported, pre-fabricated steel frame solution is relatively expensive, but quick to construct once the materials have arrived in-country. As designed, the steel frame has very limited lateral stability because there is no bracing in the walls or roof. As such, it does not perform well under seismic and wind loading. Significant alterations are required to improve its performance including modifications to foundations, steel members and bracing in the walls and roof.

Haiti IFRC 8 shelter designs

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IFRC 8 Shelter Designs

Roof Level Plan Ground Floor Plan

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IFRC 8 Shelter Designs

Durability and lifespan The shelter is demountable with foundation bolts that can be cut to reuse the frame. The intention is to put two shelters side by side to form a double pitched roof structure or four together to use as communal facilities. The frame is durable and has galvanized members. The plastic sheeting will require replacement. Constructive aspects and upgrades The shelter consists of a galvanized rectangular steel frame with an 8.5 degree mono-pitch roof and a suspended floor. The height is 2.55m to the ridge and there is no bracing. The shelter is 3x6m on plan and has 6 columns spaced on a 3m grid. The raised floor is also supported by 13 additional stub columns on 100x100x6mm base plates bearing directly to the soil. The main structure is three primary frames with rectangular hollow section columns. The shelter can be upgraded by replacing the plastic sheeting walls with plywood or corrugated metal sheet. To provide resistance to wind pressures, this upgrade will require : In-plane bracing for the roofs and walls, concrete foundations, upgraded main foundations (to prevent uplift and sliding), decreased column spacing and strengthened wall supports, roof beams and roof purlins. If the roof and walls are upgraded with heavier materials, member sizes should be increased and connections strengthened. The upgrade with masonry is not recommended. . If shelter modules are combined to create larger structures, the bracing must remain in the internal walls. Booklet

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i. Haiti - 2010 - Earthquake

This multi-story unit allows an increased living space in a small land footprint by utilizing the vertical space. This feature is beneficial in urban disasters where land is scarce. The structural frame is made up primarily of metal studs and tracks, floor levels of plywood, along with roof and wall panels of 5mm thick corrugated polypropylene connected with metal fasteners. The three enclosed floor areas in offer a total of 17.8 m².

Developed by Ubershelter

Haiti

The shelter rests on telescoping legs that can be raised or lowered to keep the shelter level on uneven terrain. Booklet

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j. Thailand – 2006 - Tsunami

This shelter is made completely of steel, In this example, the material used could provide a sustainable solution to help in the community that suffered a big tsunami in 2006. Through the creation of two stories it was possible to cope with future floods. In Addition, this structure was also designed to cope with earthquakes, typhoons and hurricanes.

150 houses supplied within weeks of flooding disaster in Thailand.

Could be erected with minimal tools and access to electricity, and it can be adapted or upgraded by families for future needs.

Thailand

Developed by BlueScope Steel. Booklet

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Low cost hospital supplied to north eastern Thailand within weeks of flooding. 26


k. Indonesia - 2004 - Tsunami This shelter is a pre-fabricated complete long term sheltering solution. A low cost housing solution that offers benefits of steel durability, termite and corrosion resistance, high strength, dimensional stability and light-weight structure. It is designed to be earthquake resistant, fire resistant, and thermally efficient due to the insulation executed under the roof. The insulation also lessens the rain induced vibration reducing the noise.

Buddhist Village – TzuChi-Desa Panteriek

It is easy to build and helps to reduce building costs through the lighter foundation structure.

Indonesia

Developed by BlueScope Steel Booklet

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Items can be also relevant in a disaster response to distribute immediately after disaster a part from the complete construction they may be part of, to enable people to repair their damaged house, or erect a temporary shelter using salvaged materials or new ones. It is thus relevant to address ‘items’ as a separate chapter.

A. I t e m s

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Connectors Strapping

•

Strapping is a simple technique to reinforce the structures in a building in order to prevent displacement. This example shows a prototype put together by strapping and tested to prove the system’s efficiency. The walls were constructed as panels, with straps on the top and bottom of the walls. The walls and the ceiling were assembled by strapping. Each rafter was strapped to the wall, and the purlins were strapped at each intersection to the rafters. After the prototype was prepared, the test was done. (see video link below). To have an efficient structure, all connections must be strapped. The building is only as strong as its weakest link.

Strapping is one of those techniques that does not cost a lot, nor requires high skills or efforts while it can contribute highly to the stability of a structure. It’s a technique relevant for disaster preparedness as well as reconstructing back better.

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Connectors • Scrap Metal Plate Connections This is a simple and cheap technique that is based on the use of thin sheet metal cut in the required shape and size to form a connector. These pieces are wrapped around the joints and firmly nailed onto the timber. The most suitable application of this method is in the prefabrication of pole timber trusses, that can be produced in the construction site before assembly of the structure, or in another place and transported to the site. To ensure uniform dimensions, the trusses are made with the help of a template laid on the ground and held in place by wooden or steel pegs, as we can see in the image on the right.

Developed at the Intermediate Technology in Cradley Heath, UK.

This technique uses scrap metal and is simple, so can be easily (re)produced. Booklet

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Connectors •

Steel Flitch Plate Connections This technique consists of mild steel sheets inserted into a longitudinal saw cut in the timber poles, connecting them by driving nails through the timber and the steel at right angles to the plate. Mild steel sheets up to 1mm thickness can be easily penetrated by normal steel nails without pre-drilling. Tests have shown that for most applications and timber species two 1mm plates provide sufficient strength to connections. (Considerations of cost suggest that it is better to increase the number of 1mm plates rather than their thickness.)

Developed at the building Research Established in Garston, UK.

The ability of the nailed flitch plate connection to sustain loads after initial failure is a characteristic which could prove valuable in areas where buildings may be subjected to earthquakes and high winds. Booklet

This is a quite basic technique, using very common materials. It is also easy to imagine to make more pieces and to see the approach copied in other shelters.

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Connectors • Steel pieces – different configurations The following examples show other prefabricated steel pieces, tailor made to make specific structural connections in a building. The programmed connections to use this kind of pieces are in traditional masonry, wood and concrete construction. Depending on the place of use, the adequate coating to cope with the environments is necessary to maintain the original structural properties.

Column Base

Elevated Post Base

Foundation Strap

Mansory Hanger

The installation is possible using different types of fasteners as nails, screws and bolts, alone or combined. The type and quantity of the fasteners used to install these tailor-made pieces is critical to the connector’s performance. For an emergency context this technique thus becomes irrelevant unless it is already practiced and known locally before the disaster hit. Booklet

Corner Brace

Purlin Hangers

Adjustable Rafter-To-Plate Connectors

Girder Truss Hangers

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Connectors • Connecting bamboo Using steel as a component in buildings made of bamboo has great advantages. Steel pieces are more secure and can be used to create all kind of connections. However, assembly with steel is very precise while assembly with bamboo isn’t. Bamboo is a material that can not be standardized and this is a major challenge.

Colombia: Footing detail

Bamboo is often combined with other materials such as concrete in fills and steel fittings to connections.

Prototype developed by Vrije Universiteit Brussel

Studies have been developed, to provide secure connections in roof structures and complete frames made of bamboo, as we can see in the example (left) developed by Vrije Universiteit Brussel. Booklet

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Sun roof at botanical garden, Miami

Refectory, Ecole Suédoise, Pointe Noire, Congo. Built in 1985, still intact.

Space Frame Connector of welded flat steel, developed by Habitropic. 34


Connectors • Space Frame Connections

This method is based on the use of short length pieces to construct space frames for large covered areas. These pieces were initially developed to work with local timber, but there are some studies that mention the use of these pieces to work with other materials as bamboo. The system is based on special space frame connector, comprising of cross-components of welded steel, and tail end connectors with screws, washers and nuts.

Developed in Sweden by Habitropic.

It’s not a cheap solution, but it’s a valuable idea to support a mixed use of materials, combining local resources with steel pieces.

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Wires, cables, meshes and rods •

Galvanized steel wire mesh and expanded metal

• Hexagonal wire mesh is the cheapest and easiest to use. It is very flexible and can be used in very thin sections, but is structurally not as efficient as meshes with square openings. It's popularly known as chicken wire. • Square welded wire mesh provides increased resistance to cracking. • Square woven wire mesh is a little more flexible and easier to work with than with welded mesh. • Expanded metal lath provides a good impact resistance and better crack control. It cannot be used to make components with sharp curves. Booklet

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Wires, cables, meshes and rods • Seismic retrofitting – belts

Anchoring vertical WWM to wall with nails.

Installing WWM around window opening

Galvanized Welded Wire Mesh (WWM)

Plastering vertical WWM belt using cement plaster. Booklet

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Completed encasement belt around window 37


Wire mesh in planned and unplanned constructions

xample Example

The shelters on the left were constructed after the tsunami in 2005, using hexagonal wire mesh or ‘chicken wire’.

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The shelters on the right were built in makeshift camps and refugee areas in Europe, mainly next to the Calais Port, France. They were built from all sorts of waste materials, including steel wire mesh tied together with bits of rope and tape.

Calais, France, March 2008.

Calais, France, July 2009.

Calais, France, July 2009. Booklet

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Wires, cables, meshes and rods • Space Frame Connections Structures can be braced for stability purposes (imperfections) and to accommodate horizontal loads (winds). The diagonals solid bars are connected to the beams and columns by means of bolted gusset plates or direct welding. Cables have a much higher strength than solid bars and can accommodate higher loads. However, they are considerably more expensive and must be prestressed during erection in order to prevent the cable from sagging. The lengths of tie bars provided with leftand right-hand threads at opposite ends can be easily adjusted on site by screwing them into matching end fittings.

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Wire and Cables • Emergency shelter - Peru This is an emergency shelter constructed in Pisco, after the earthquake in 2007, Peru.

Wire – IFRC Shelter Kit

The shelters were built from local materials and adequate to the context. The frame, walls and roof are made of materials commonly used in the area.

Pisco, Peru.

Example xample

The frame was prepared using the bracing technique with wire in form of “X” to act as tensors keeping the shelter stable. This is a simple way to improve the stability, and can be easily executed using hand tools.

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This project doesn’t have a foundation, and it was necessary to use steel wire to make sure that it didn't move. In structural terms, this element is known as a tensioned structure. In sheltering, this simple wire is mostly used to connect bamboo poles. In this case however it is the entire concept, of which the wire is part, that makes this structure a good solution for transitional sheltering.

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Wires, cables, meshes and rods • Rods and rebar The function of the bond element dictates the characteristics of the reinforcing bar used. Stitching element bar: Used to stitch together the withys of a thick wall, seismic belt shear connector bar: Used to anchor welded wire mesh seismic belt in masonry wall, vertical reinforcement shear connector bar: Used to anchor vertical reinforcing bar onto wall corner. Rebar is widely used for foundations and concrete reinforcement. For temporary shelters in humanitarian aid it is expensive, but is recommended when more resistant solution are necessary. Steel and concrete have similar coefficients of heat expansion. A concrete structural reinforced with steel will experience minimal stress. To counter concrete’s lack to stand tension, rebar sticks are cast into it complementing the compression resistance of concrete. Booklet

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Rebar • Retrofitting Bangladesh

Reinforced concrete post executed in Bangladesh.

xample Example

This is a relatively expensive option, certainly for its context, but is resistant to deterioration by water. All posts of the shelter should be made of reinforced concrete. Bamboo or timber post may rot at base and the structure may collapse. Should be used: four steel 3/ 8” diameter rebar, one at each corner, tied together with ¼” diameter stirrups ,with 8”-10” nominal spacing. Post section = 4” x 4“. Length should be determined according to depth of penetration required into plinth and ground according to local soil conditions and plinth height. It's better to have a small spread footing for stability and to avoid leaning over during flood.

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For attaching to roof structure, the re-bar can be bent around the purlin for better grip. To prevent rust, the re-bar should be painted with molten bitumen.

This is an example of how a structurally crucial element of a shelter can be an ‘item’ that can be prefabricated, installed and moved. In the Bangladesh context, where many shifting rivers take and make land constantly, this is a great benefit. Booklet

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Fasteners • Nails

These are simple nails for building with timber. They are part of IFRC’s shelter kit.

Roofing nails Roofing nails are special nails with washers used for fixing tarpaulins or roofing sheets to timber. When used properly the nails prevent rain seeping through.

Nails are handy for putting up and repairing temporary structures with little skill and equipment, though they can also be used in structures to resist more long term Booklet

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Fasteners • Screws Roofing Screws are widely used in the residential wood construction market, but their use is not as common as nails. However, screws and bolts are among the most important types of fasteners used in structural frameworks. The advantages of screwed connections: -Easy to handle on the building site. -Excellent availability in various qualities and strengths. -Easy removal if necessary – an important prerequisite for the dismantling and reerection of steel components.

Appropriate for installations in wood surfaces and mild steel plates without pre drilled holes.

Facade

Roofing

Facade Screws have more durable characteristics and needed to obtain minimum strength in certain parts of more durable constructions Booklet

Appropriate for steel surfaces.

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Fasteners •

Nuts and bolts

Bolts are often used for “heavy� connections and to secure wood to other materials such as steel or concrete. Bolts are typically used to anchor wood members to foundations, ledger plates to wall framing, or in wood decks. Bolts with a hexagon socket are approved for structural connections. Depending on the material of the bolt (strength grade) we can distinguish between standard and high strength bolts. Bolts can be loaded in tension, in shear or a combination of both. Foundation bolts, typically embedded in concrete or grouted masonry, are commonly referred to as anchor bolts, J-bolts, or mudsill anchors. In residential wood construction, bolted connections are typically limited to wood-to-concrete connections unless a home is constructed in a high-hazard wind or seismic area and hold-down brackets are required to transfer shear wall overturning forces.

Typical bolt types and connections for residence use.

Bolts are essential parts of more permanent structures to add resistance in crucial point of the structure. They however cost more and the effort to use them is greater. Booklet

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Fasteners • Rivets Riveting creates a non-detachable connection between parts of the structure. Due to the excessive noise and that they are labor-intensive, the traditional (solid) rivet has been replaced by the newer model. The newer, easy-to-use pop rivets are used in the building industry mainly for fastening thin sheet metal components. Pop rivets, which require access from one side only are especially useful when working with hollow sections.

Operations for inserting a pop rivet.

• Hooks One common use of J bolts is as cast-in-place anchor bolt. J bolts provide a great deal of support and stability, and the shape hooking the bolt in place fits adequately and will not come loose. When installed to fix purlins, they can avoid the roofing up-lift during high winds. Booklet

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Fasteners • Welding Welding involves fusing together two or more identical or very similar steels to form one homogeneous component, and this is done by melting them together at their interface through liquefaction or plastic deformation. This can be carried out with or without the addition of another material. Good quality weld seam.

For proper welding one needs electricity, an appropriate (‘clean’) environment and protection and skilled welders. Welding is thus not recommended for each context. Another important point is that the on-site weld seams should be treated with a subsequent application of corrosion protection coatings, which isn’t always possible to perform on site. Poor quality weld seam.

• Glue-ing Steel elements can be glued. Similar concerns regarding surface and environment cleanliness have to be taken into account as with welding.

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CGI sheets are probably the most common use of steel in humanitarian sheltering. CGI sheets has obvious benefits, but is often a poor solution. Other sheets and panel solutions are rather expensive for humanitarian sheltering, although they could reduce the issues encountered with CGI sheets.

B. S h e e t s a n d P a n e l s

Paneling systems can be self-supporting, avoiding the need for supplementary structural material. The fact that sheets and panels are usually pre-fabricated could be looked at, perhaps more local(ised) options are imaginable.

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Roofs and Walls

The most common uses of corrugated metal sheets are walling and roofing, in different thicknesses and coatings. To consider the use of galvanized sheeting in humanitarian aid, it is relevant to know that the sheet is not available in all countries which adds expensive shipping and local transport to the final price. To install the sheeting, wooden or steel purlins are fixed over the principal rafters. The spacing of purlins should be determined by the size of the panels, to avoid cutting. The spacing of the nails is crucial in areas prone to high wind speeds. Too many nails will turn the sheet into a ‘rip off paper sheet’, too little will allow the nailing holes to be punched through and the sheets flying off entirely. Corrugated metal roofs are cooler by 5°C when painted silver grey than they are when left in their natural state. There are two types of paint: emulsion and gloss. Numerous treatments can be applied to materials to protect them from wear and tear. Typically, one litter of paint will cover 10m². Red lead/oxide paint protects metal from rusting. Paints and treatments should always be applied in a well-ventilated space. Booklet

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Roofs and Walls • Roofs and walls

Sri Lanka – 2007 – Conflict Returnees

Kenya – 2009 – Conflict Refugees

Thailand – 2006 - Tsunami Somalia – 2009 - Conflict

Bangladesh – 2007 – Cyclone Sidr Booklet

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Corrosion in air: Humidity, temperature, rain, wind, impurities and how long the metal is wet have an effect on the corrosion rate. Corrosion occurs when the relative humidity of the air is 70 to 80%. Corrosion reaction is possible generally when the temperature is above 0°C and the relative humidity is over 80% (the surface is wet). Air impurities that dissolve in condensed water or rain water may accelerate corrosion. Settling of dust and dirt on the metal surface accelerates atmospheric corrosion. Steel Days

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Roofs and Walls •

Corrosion Metals react with the environment, producing corrosion products similar to the original ore from which the metal was obtained. Corrosion processes are electro-chemical reactions taking place at the surface of the metal. However, corrosion products (rust) may act as a barrier between the metal and its surroundings, slowing down the corrosion rate. In some cases this barrier very effectively delays corrosion. This is called passivation, and can increase the corrosion resistance of metal remarkably.

_ Hot Dip Galvanizing _ The most common method of

_ Corrosion Protection _ The most common surface

protecting steel construction products. Very simply, the process involves coating the surface of the steel with a corrosion-resistant metal, usually zinc or an aluminum/zinc alloy. Zinc and zinc-based coatings protect steel in two ways. Like paint, they provide barrier protection. Secondly, they provide galvanic protection. The zinc will sacrifice itself to protect steel.

protection methods for steel are: • Anti corrosive paint coating • Hot dip galvanizing • Electroplating • Spray galvanizing • Chromium plating • Aluminium spraying • Rubberising • Coil coating of sheet steel

_ Anticorrosive Painting _ Paints are barrier coatings that, when applied and used properly, give sufficient corrosion protection to steel. They are, however, not impervious to moisture, and rust can occur under even a perfectly applied paint if exposure time to moisture is long enough. For this reason, surface cleanliness and preparation are essential for good protection by anticorrosive paints. Booklet

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Roofs and Walls There is no doubt that the finished level of the steel sheet is directly related with the material's life expectancy on the shelters.

• Thickness versus price

In the graphic beside, we can see the comparative curves between the steel sheet painted price (colored), the steel sheet galvanized price and the steel sheet without treatment.

6

Price ($/m2)

5 4 3

One of the most commonly used thicknesses in temporary sheltering is about 0.40mm. However, the chosen thickness is often dependent on the availability in the local market, and the price demanded by suppliers.

2 1 0 0,2

0,3

0,4

0,5

0,6

Thickness (mm) Price (colored) Thickness

Price (galvanized)

Price (untreated)

0,2

0,3

0,4

0,5

0,6

Price (colored/painted)

2,64

3,3

4,08

4,8

5,64

Price (galvanized)

2,43

3,03

3,79

4,42

5,3

Price (untreated)

1,5

1,98

2,78

3,38

4,28

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The prices can be found in the table below, and the currency considered was USD per square meter. * Figures obtained from a Chinese supplier, excluding the shipping rate.

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Panels

Metal panels are usually a prefabricated element, however they can be made at the construction site as well. It's a durable material, lasting from 20 to 50 years, but requires skilled labor and special equipment to assemble. It can be adequate for a wide climate range and the cost is high for humanitarian standards.

Paneling is not much used yet in humanitarian sheltering. One of its possible benefits is the interior climate it can create.

Metal panels can be presented in two forms. The first system is similar to standing seam metallic roofing and differs only in the fact that the edges of adjoining panels are not seamed together, but overlap, providing a watertight seal. Generally the outermost layer protects the construction against the weather while the building performance requirements are achieved by the underlying layers. In terms of functioning, with or without an air cavity exist. The second system is prefabricated composite panels that can provide insulation and durable roofing or walling. These panels are composed of mineral wool or foamed insulation "sandwiched" between metal sheets. Booklet

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Composite Panels 54


Panels • MiiHome System The MiiHome is an emergency housing system, moveable and demountable.

Product information

The system is based on structural panel construction, replacing the need for traditional frames and trusses, cladding linings and veneers. The structural panels are interlocked and fixed together using various steel extrusions and fasteners. The panels are light weight and arrive at the construction site ready to assemble. Floor panels are 140mm thick and strengthened by a series of integrated bearers. The external walls are140mm thick and are engineered to achieve load bearing capabilities including a high level lateral load to cope with cyclonic, seismic and flood conditions.

4

The roofs panels are 125mm thick, manufactured with a roof sheet profile as an external outer skin, and a smooth prepainted underside skin for internal ceilings. The windows and doors are made of steel frames.

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Panels

• UK – 1945 – Post conflict (World War II)

This steel prototype shelter has 57m² area, a living room, two bedrooms, kitchen, bathroom, WC and shed. The British government built 156,600 prefabricated houses as a temporary measure over the space of three years, with an anticipated lifetime of 10 years. Many have been occupied for a far longer time, though the maintenance of these houses is expensive.

Example

The first prototype developed was a prefabricated single storey house with two layer steel walls. There was an aluminum foil lining between interior and exterior walls. The houses were built on a concrete slab, and in cold weather, the steel prototype suffered severely from condensation.

5

Following the failure of the first steel prototype shelter, four main types of house were later selected, which accounted for 90% of the final houses constructed. • 1st - Concrete base, steel frame and cement exterior cladding. • 2nd - The frame was made of plywood and timber, with asbestos wall sections. • 3rd - A wooden framed bungalow with precast concrete panel walls. • 4th - Aluminum bungalow – The aluminum bungalow was the most expensive to produce. In general there is now a policy of replacing prefabs, because it is cheaper to demolish and rebuild rather than continue to repair them. Bristol, UK. Booklet

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Panels

• Protea Protea is a modular construction system, and a structural panel construction as well.

Product Information

It's low cost high quality housing, using composite structural panels as walling, and insulated panels as roofing. Wall panels - Composite structural panels

The thicknesses can be adjusted in different climate conditions, and the panels have galvanized and pre painted coatings.

Roof panels - Insulated roof panels

The installation is made with different types of screws, and "U" profile elements are used to join walls and roof panels, fixed to the top of all the wall panels.

6

The system offers thermal and sound insulation plus seismic and wind resistance.

This type of solutions is too expensive for most contexts, but may be relevant for more middle-income contexts.

Developed by ArcelorMittal Construction Booklet

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Steel frames can be very relevant for humanitarian sheltering. Here the design challenge is possibly largest, as each frame should be adjusted to the context it is being used in.

C. F r a m e s

Some of the challenges are the local production and maintenance of steel frames, and the combination with local materials for roofing, walling, interior separations etc.

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Profiles

The variety of existing steel profiles is quite wide and we cannot expand upon that in this booklet. The structural strength, production speed and quick assembly that can be given by using metal profiles is probably one of the most interesting applications of steel for sheltering. To make this happen in combination with local materials and in conjunction with the local construction is an interesting challenges.

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Profiles This prototype offers 24m² area, and the dimensions are 4x3m. The frame was designed using galvanized steel as material, and the roof was designed with corrugated gauge Iron 0.4mm thick.

The prevision for the floor on the ground is rubble, the 1st floor plywood.

Prototype

The frame comes with a base plate to make the foundation in two ways. For permanent locations, cement and rebar or concrete expending anchors are recommended. For transitional locations, ground anchors can be used.

The structural parts are connected together with bolts and nuts, and the roof capping and the plywood are fixed to the structure with screws. It takes 4 hours to erect and no power tool are required to assemble it.

7

Draft Concept Design

Details of prototype by TU/e

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Profiles • Family tent IFRC – UNHCR ICRC

Product information

This product is designed to withstand many types of climates, and provide a good and protective shelter in both emergency situations, natural disaster or for refugees. The total area is 16m2. The outside dimensions of the tent are 4 x 4m, and the central height is 2,2m. The material used in the frame is Steel Tube 25/1,5mm, white epoxy.

8

The cover material can be used single fold or double fold, to have an ideal weather performance. Serves from 6 to 10 people.

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Profiles • TransHome This frame offers 17.64 m² living area and is made of mild and stainless steel.

Product information

Initially the walls and roof can be covered with polyethylene plastic sheet to get an emergency shelter. After the first stage, the walls can be replaced by a variety of material as for example bricks, mud, and bamboo, or even by other materials available locally; and the roof can be replaced by bamboo, straw, grass or even CGI steel roof. To cover the ground, the IFRC / ICRC type Polyethylene plastic sheet is used.

9

The required tools are; hammer, spanner, screwdriver and the assembly instruction.

Base Plate Developed by NRS International Booklet

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Profiles • Losberger This transitional shelter combines the emergency tent and temporary housing in an easy transportable and constructible shelter.

Prototype

For twice the costs of a traditional family tent, this shelter is a temporary house based on a re-useable and durable aluminum frame. This model was developed following the ‘transitional shelter standards’, and is made of aluminum L-profiles 2000x40x40x4mm, and 3mm steel cable, galvanized, for bracing. It has 17,5 m2 area, and 530x330x270cm (LxWxH) internal size.

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Developed by Losberger Booklet

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Trusses Steel trusses can be produced locally, can be placed and removed again to re-use somewhere else.

Mild Steel or Galvanized Iron roof structures can be made typically with 1½ inch x 1½ inch x 1/8 inch sections, and it is advisable to make trusses for better strength, to make a variety of designs with different loads possible. The roof structure elements can be welded to each other, but if welding equipment is not available or quality welding can not be guaranteed, they should be designed to be connected by nuts and bolts. Mild steel angle roof structures should be painted with corrosion resistant paint (red oxide fe).

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Profiles • Reciproboo This shelter prototype is a combination of a tubular steel frame, gabion and rammed earth.

Prototype

The steel forms a linking framework for the gabion blocks and rammed earth blocks or panels to be built around. Furthermore, the roof frame of interlocking steel tubes covers a large surface with minimum use of materials. It ensures that all the weight will be transferred vertically onto the load bearing walls without the "spread-forces" exerted by traditional roof structures.

11

Locally available building materials that are combined with a minimal imported framework. There are three basic frames and each one is made from being wired together interlocking 1m lengths of 22mm gauge steel tubing, as showed in the first picture above. Developed by Reciproboo

4

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Trusses Structural steel elements are assembled together to form a simpler structure as in this case where we can see a kind of beam grid, formed by an "I" section beam and purlins in different directions joined in one plan. The use of steel "I" section beams in humanitarian aid is regularly seen in mixed structures to form or give a stronger base to receive the roofing.

Example

• Afghanistan repatriation, 2002-2008 This shelter project in Afghanistan began with building mud-blocks shelters with wooden roofs, windows and doors. Due to supply and sustainability issues, steel was used to replace the timber. We can see in the pictures beside a flat roof made of steel beams "I" section and steel purlins. The doors and windows were also replaced by steel frame structures.

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Certainly because of insecure land ownership in many countries in the world, foundations for shelter can be challenging.

D. F o u n d a t i o n s

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Anchor • Earth anchors The arrow anchors vary in size from 2" up to 17" in width, and the illustration on the right shows how they can be installed. The installation can be made manually or with hand tools, reducing costs. The arrow head does not require any costly digging, sophisticated machinery or excessive manpower. The anchor can penetrate quite stiff and rocky soils because of the triangular design that tends to thread its way between obstacles.

This technology is very useful to give a minimum of strength to both temporary and transitional sheltering solutions, also because it’s quite easy to install and not expensive.

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Steel Plate • Loose rubble foundation This foundation is not as strong as a concrete foundation but might have several advantages in an emergency situation where no other technologies are available. This is dry construction. The rubble material available after a natural disaster is being made useful to construct a shelter. This technique avoids burying timber posts, and will last until the weld mesh corrodes. First it is necessary to dig holes, in the size and number required by the shelter's design. Then, the weld-mesh square should be placed at bottom of each foundation pit. Minimum 10mm weld mesh. The hooks in a length of 10 or 12 mm rebar should be fixed to the mesh (1st image). After that, the holes should be filled with rubble. It's useful if the larger pieces are put on the bottom, and after that the voids are filled with well compacted dirt (2nd image). Timber or steel structure can be connected by bending the re-bar (3rd image). If there is a necessity to have a more durable solution, the foundation can be improved encasing the weld mesh in a weak concrete mix. Booklet

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Anchor • Heavier anchor foundation The anchoring system is better than conventional methods of stay anchoring, and requires no excavation thus saving time and labor. With the use of portable tools, multiple anchor installations can be achieved by a team of two within a very short period of time. The design on the right shows the foundation's details in a core wooden frame shelter, executed with the anchor system. In the draft below we can see how the anchor is installed in a building site.

This version of an anchor foundation starts to be too complicated for many emergency situations.

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• Phillipines This concept emphasizes the mixed use of materials to reinforce a shelter against the lateral wind loads. The method consists of the use of iron bars box and an anchor piece in the extreme of the timber poles, buried into the concrete. In 2006 and 2008 the typhoons Durian and Fengshen struck the Philippines.

Example

5.3 _ Box Box

The Philippine Red Cross, with support of the IFRC, launched a reconstruction and recovery program to help people build their own homes while introducing more durable shelter solutions.

13

About 14000 beneficiary families have adopted these improved construction techniques.

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Steel Plate • Steel plate This system uses a steel plate as base to support the foundation. It's a simple method where a hot dipped galvanized steel piece screwed to a timber pole is used, treated in advance. After putting the elements together, it is necessary to dig a hole and place the pole. The hole should be filled with compacted soil or concrete to finalize the foundation.

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Box • Central Vietnam This shelter was constructed in Central Vietnam after a flood happened in November 1998. The platform has a 24m² including mezzanine, the frames and roofing are completely made of steel and the foundation is made of 4 rebar pieces joint with a square wire mesh buried in concrete.

Example

This foundation is appropriate for more durable shelter solutions due to the resistance offered to the structure.

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Screw • Foundation repair for damaged structures

Resistant solutions for foundation problems, based on soil conditions, damage and structure's weight. The installation begins by excavating down the footing at each screw location. The footing must then be notched to accommodate the bracket. A hydraulic torque drive is used to screw each piece into stable sub soil, until designated depth is achieved. The bracket is then installed on each pile and securely attached to the foundation. The foundation is raised to the predetermined level and stabilized. After that, all holes are backfilled and the site returns to the original condition.

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Screw • South Vietnam This shelter was constructed in South Vietnam after a floods in august 2000. The platforms are 26m² and the screw foundation support a steel frame. To install this, it is necessary that a turning moment is applied to the head of the screw pile, and the pile is "twisted" into the ground.

Example

The advantages are the rapid installation without complicated equipment, the immediate load-bearing capacity and that no casting or dewatering required. It can be removed and reused. This is a heavier and more expensive element, still it is easy to install, gives high quality. The fact that it can be removed and reused is an extra benefit.

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• Concrete Stump - Kaatla

Example

Method used in Bangladesh for protecting the base of bamboo/timber posts by supporting them by concrete stumps embedded into the plinth or ground. The posts are connected by mild steel clamps, locally known as kaatla or shiri.

16

The greatest advantage is the reduction of recurrent expenditure on replacing bamboo or wooden posts. A bamboo post protected from the ground by kaatla, lasts five years or longer, which is double the normal lifespan. For a bamboo post supported by kaatla, it is better to paint the lower end with bitumen for additional damp proofing. The bar should have two 3/8" holes towards the upper end to insert screws for attaching the post, thus serving as a clamp. Casting should be done with cement. To prevent rust, the Mild Steel clamps should be painted with molten bitumen.

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The images beside shows the kaatla foundation being prepared to be installed and in the scheme, the kaatla supporting bamboo poles. Concrete stump (kaatla) for protecting lower end of bamboo post

Details of hollow kaatla and its production

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E. Other Aspects

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Recycling Steel is produced from iron ore, one of the most abundant elements on our planet. However, since it is 100% recyclable, and easily handled and separated from other materials, 42% of the total world crude steel annually produced is made from scrap. Around the world, about 80% of all steel that becomes available is reused or recycled in some form. In terms of construction, at the end of useful life, steel buildings can be disassembled and the various components can be re-used or recycled without loss of properties. Over the last fifty years, the consumption of energy required for the production of steel as well as the CO2 emissions have been reduced.

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Life Cycle Steel products present a lot of advantages, but it is necessary to analyze the material’s life cycle to understand the environmental implications in using it. The life cycle of a building and components provides a framework with the various environmental impacts, for the identification of sources and possible improvement. The graph on the left hand page shows us the steps and the fluxes of different natures.

Steel construction has some features that lessen the impact on local environments: Waste: Prefabricated steel products generate less waste. Moreover, the waste generated is easily collected, segregated and recycled. Water and dust: Steel construction is mainly based on "dry techniques" and dust-free.

The first thing that should be evaluated is to consider procurement abroad to have steel elements. Many countries in a fragile situation don't have steel industries.

Duration: Steel construction is fast and minimizes the duration of the site occupation for construction activities.

On site using steel is very clean compared with traditional techniques. But the raw material extraction, industrialization process and transport is rather different.

Natural resources: The steel use in construction avoids the inordinate use of natural resources and prevents deforestation without replacement, and even illegal logging in the remaining rainforests.

There is no doubt that each case should be evaluated to apply the best material solution, depending on location, climate, local culture, environment and response speed

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Climate design Using steel sheets to cover shelters is fast, easy and in many cases the cheapest option available in an emergency situation.

Inside a shelter the dynamic is the same. When the sun hits the construction, the hot air inside the building becomes less dense and rises, creating a stationary hot layer, heating the shelter.

However, the use of this material is inadequate in many areas that have intense solar radiation and rapid temperature changes because of the excessive heat inside the shelter, condensation problems or lack of insulation. In addition, shelters covered with sheets can be very noisy.

In the design above, we can see the dynamic air scheme on the atmosphere.

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Strategies If we work with openings, at the top of the roof and walls, the hot air will move inside the shelter searching a superior exit. However, there are many techniques to ventilate depending on the available materials, the direction of the wind and the shape of the roof. In addition, a better climate inside the shelter can be achieved if we use other strategies also, as is shown below. A _ This method consists on wind flowing in through one eave or window out of the roof, and allows a great interior comfort. B _ The circulation B is made with the wind flowing through the eaves. C _ In this example, the wind flows through the upper part of the wall. D _ This technique is used to restrict solar gain through the window‘s shading.

A

B

C

D

E _ In this example an insulating material between the roof and shelter interior restricts the gains by conduction. This method helps also to reduce sound transmission. E

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Strategies • Shelter orientation Another important way to have better ventilation inside a shelter, is to locate the building properly in relation to the prevailing wind in the area. In the table below, we can see the ventilation percentage, related to the window opening axis. When openings are located in a strategic position, it can have a greater percentage of ventilation . Situation Plan Perpendicular Wind

Parallel Wind

Axis opening x angle

%

0

100

45

97

60

87

70

31

90

0

Prevailing wind

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Strategies • Ventilation area Elevating a shelter from the ground is also beneficial for ventilation.

This case in Vietnam is shows an elevated shelter. In this construction a steel frame was used, whose properties contribute to building a two storied shelter or even an elevated first floor. This alternative is often used to cope with flood areas, but can contribute also to the better climate inside the shelter through ventilation made possible under the shelter. South Vietnam Booklet

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Strategies • Window Design 1 and 2 – 100% ventilation, while opened. 2 – Has an hygienic ventilation, because there is a possibility of air changes with the shelter. 3 – Reduced area to enter the winds, but provides the possibility of free direction of the winds. Works as a « barrier», protecting the shelter against the sun. It’s ideal to rainy days, because provides light and wind without rain water. 4 and 5 – 50% ventilation, while opened.

1

2

• Walling

3

The walling solution beside is widely used in tropical climate countries where there is a need for good ventilation. This technical solution can be used in both low cost and high cost housing.

4

The technique consists in using a wall made of leaked plot wood or other materials. It’s very efficient, because the openings provide air changes and visual privacy. 5

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Aluminum - Aluminum is a common element, but the energy needed to reduce alumina (or aluminum oxide) to the metal is very high.

- Aluminum is simpler and more versatile than steel to produce and fabricate. - Aluminum is the third most common element in the earth crust, after oxygen and silicon.

- The aluminum modulus of elasticity is only one-third that the steel, and compared to stainless steel it's more liable to buckle, and it also deflects more.

- Aluminum can be cold-rolled like steel and stainless steel.

- Because of its higher deflection, it is usually necessary to use aluminum sheet that is thicker than steel sheet would have to be for the same purpose.

- One main advantage of aluminum over structural and low-alloy steels is its corrosion resistance - The lower weight is also frequently an advantage, certainly for humanitarian aid.

- One main disadvantage is its higher cost.

Recent decades have seen a great increase in the use of aluminum for windows, curtains, walls, reflective insulation, roof sheets and builder hardware. Booklet

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Sources

91


VIDEO SOURCES 1

http://www.youtube.com/watch?v=7GZDI8iT-jQ

2

http://www.youtube.com/watch?v=EnORQpv5Okg

3

http://www.youtube.com/watch?v=_a_OWYNSrPE

4

http://www.youtube.com/watch?v=Rr-U0GcbE9I&feature=player_embedded

5

http://www.youtube.com/watch?v=eThTpMvdst4

6

http://www.youtube.com/watch?v=ZwCMX2pm5k8&feature=related

7

http://www.youtube.com/watch?v=X1Z2XFsAgVo&feature=player_embedded

8

http://www.youtube.com/watch?v=M4tg_wudimw

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SOURCES Transitional Settlement: displaced populations Tom Corsellis and Antonella Vitalle / University of Cambridge Shelterproject, Shelter Centre, Oxfam GB (2005)

Manual for Restoration and Retrofitting of Rural Structures in Kashmir UNESCO – New Delhi Office, UNDP India (2007)

Hybrid Wood and Steel Details Builder's Guide Prepared for US Department of Housing and Urban Development by NAHB Research Center, Marlboro, MD (2003)

Connect with confidence – USP Professional Design Manual and Product Catalog USP Structural Connectors – 56th Edition.

Designer Handbook _ Stainless Steel Fasteners Directory of Fasteners Manufacturers

Steel and you – Sustainable Solutions for Life International Iron and Steel Institute

TS 200 – Transitional Shelter Losberger

Handbook on Design and Construction of Housing for FloodProne Rural Areas of Bangladesh Dr. K. Iftekhar Ahmed / Asian Disaster Preparedness Center (2005) Booklet

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Shelter Kit Brochure International Federation of Red Cross and Red Crescent Societies (2009)

Detail Practice - Building with Steel – Details, Principles, Examples. Alexander Reichel, Peter Ackermann, Alexander Hentschel, Anette Hochberg (2007)

Appropriate Building Materials – A catalogue of Potential Solutions Roland Stulz and Kiran Mukerji (1981)

Roofing Primer: A Catalogue of Potential Solutions Roland Stulz (2003)

Designer Handbook _ Standard Practices for Stainless Steel - Roofing, Flashing, Copings. Specialty Steel Industry of North America

The Barefoot Architect – A Handbook for Green Building Johan van Lengen (2008)

Shelter Projects 2008 UNHABITAT, UNHCR, Internacional Federation of Red Cross and Red Crescent Societies (2009)

Fencing_Installation Guide BlueScope Steel (2003)

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TransHome - Transformable Shelter NRS International - Noor Relief Services

Shelter Projects 2009 UNHABITAT, Internacional Federation of Red Cross and Red Crescent Societies (2010)

The Transitional Shelter Programme Internationql Federation of Red Cross and Red Crescent Societies (2007) Shelter Henk Wildschut (2010)

Product Catalogue – Transitional to Permanent Shelter Framing Packages Versatube Building System

Pakistan Earthquake – Challenges & Innovations After the 2005 Earthquake Habitat for Humanity (2008)

Bangladesh Cyclone - Rebuilding after the Cyclone Sidr Habitat for Humanity – Asia-Pacific Office

Haiti Transitional Shelter Design UNOPS – Haiti Operations Centre

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Protea_Brochure web ArcelorMittal Construction (2011)

Hurricane Resistant Shelter_Strapping Bill Flinn / Sustainable Construction Workshops - Oxarch

Emergency House Solution The Pearls Mii Home (2003)

Bamboo Tour Ingemar Saevfors, architect; Stockholm, Sweden (2007)

Transitional Shelters - Eight designs International Federation of Red Cross and Red Crescent Societies (2011)

Family Tent 16m² International Federation of Red Cross and Red Crescent Societies

Steel Shelters for Emergency Relief BlueScope Steel (2010)

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UberShelter UberShelter (2010)

Flat Pack Home Haiti House / Perma Shelter

Tru-lift Pier Tech Systems

Basic Manual for Assembling CHF Temporary Shelters Calgary Homeless Foundation (2010)

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http://www.ifrc.org/ http://www.haitihouse.org http://www.livingsteel.org/ http://www.habitat.org/ap http:/www.miihome.com.au http://www.alpinter.com/ http://www.reciproboo.org/ http://www.dinsons.com/nrs/trans-homes https://www.milspecanchors.com/ http://www.piertech.com/index.php http://www.bluescopesteel.com/ http://www.ubershelter.org/about.html http://www.usaid.gov/ www.steelelements.com http://www.transitionalshelter.org/www.transitionalshel Losberger ter.org/TS200.html Versatube http://www.versatube.com/ Steel Elements International http://www.steelelements.com/documents1.cfm https://sites.google.com/site/shelterhaiti2010/technica IASC_Inter-Agency Standing Committee l-info/library-of-best-practice

WEBSITES USED FOR BOOKLET

IFRC Haiti House Living Steel Habitat for Humanity The Pearls MiiHome Alpinter ReciproBoo NRS International Mil Spec Anchors Pier Tech Earth Screws BlueScope Steel Uber Shelter USAID Steel Elements

Photograph by Jonas Bendiksen

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Literature review for shelter after disaster Royal Roads University, FP Innovations, Shelter Centre (2011)

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S H E LT E R I N G L I T E R AT U R E

Shelter after disaster UK Department For International Development, Shelter Centre (2010) Handbook for emergencies United Nations High Commissioner for Refugess (2007) Humanitarian charter and minimum standards in shelter response The Spherer Project (2004) Emergency shelter cluster: key things to know Emergency Shelter Cluster (2011) Transitional shelter: understanding shelter from the emergency through reconstruction and beyond Sam Collins, Tom Corsellis, Antonella Vitale / Active Learning Network for Accountability and Performance in Humanitarian Action (2010) Transitional shelter: essential criteria to be met Practical Action (2008) Transitional shelter quality, standards and upgrading guidelines United Nations High Commissioner for Refugees (2005) Myths and realities of prefabrication for post-disaster construction Colin Davidson, Gonzalo Lizarralde, Cassidy Johnson (2008) Transitional shelter standards 10b (draft) Shelter Centre (2010)

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www.alnap.org www.adpc.net www.clustercoordination.org http://www.sheltercluster.org/default.aspx www.humanitarianreform.org

R E L E VA N T W E B S I T E S

Active Learning Network for Accountability and Performance in Humanitarian Action (ALNAP) Asia Disaster Preparedness Centre (ADPC) Cluster Coordination Emergency Shelter Cluster Humanitarian Reform International Federation of Red Cross and Red Crescent Societies (IFRC) Reliefweb Red Cross Red Crescent Climate Centre

www.ifrc.org www.reliefweb.int www.climatecetre.org www.sheltercentre.org; www.shelterlibrary.org www.sphereproject.org www.unhabitat.org

Shelter Centre The Sphere Project Un Habitat

Photograph by Jonas Bendiksen

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Steel Days Scoping Study 021111 as printed SDs(1)