GREEN BUILDING BY SUPERADOBE TECHNOLOGY PRESENTED BY HARISHMA RAVEENDRAN

INTRODUCTION Form of earth bag construction Sand bag and barbed wire technology Developed by Iranian architect Nader Khalili in 1984

Nader Khalili

SHAPE Can be used to build a house of almost any shape Rectangular or circular like dome, arch, vault etc Circular domes are most stable bldg Commonly provide 60 degree inclination to the walls

HEIGHT Thickness of wall Placement of interior walls Placement of buttress walls For small domes ht = dia Some times conventional roofing systems are provide

MATERIALS 1. Bags may be polypropylene, or burlap 2.Fill material may be earth or sand, cement or lime, clay and gravel 3.Barbed wire and regular wire 4.Wheel barrow 5. Mechanical pumps 6.Compass 7.Additional materials are tampers, water, shovel, nails, scissors, woods or metal or pipes & small buckets or coffee cans

POLYPROPYLENE BAG BURLAP WHEEL BARROW

BARBED WIRE

REGULAR WIRE COMPASS COMPASS

PROCESS Collect tools

Prepare earth mix Add enough water to ball together

Dig fdn trench 30 cm deep & Level it and compact Place door away from wind

Place bags in the trench and fill bags like a short column Fill bags full as possible & check position with compass tool

Twist & tuck under the bag’s ends to close Compact the filled bags as hard as possible

Attach conts barbed wire Continue coiling bags

Door way and windows are made by proper cutting Stabilized earth must be cut after tamping at every row

Insert pipes for windows sloped to outside to rain

Provide arched entry to protect the entrance Sky light is provided at top Provide arched entry to protect the entrance

FINISHING Plaster the exterior Coating with water proof materials

Covered with reptile from top to bottom Cement or lime plaster finish

SERVICEABILITY CONSIDERATIONS Floor of a Superadobe building is usually finished last so that plumbing and electrical lines can be run underneath Plumbing pipes are placed on, in, or under the lower Superadobe layers and run vertically through small channels cut in to the walls Electrical lines are run through flexible conduit that follows the contours of the bags

STRUCTURAL CONSIDERATIONS Transfer their stresses along the surface of the structure and not from element to element like column- and beam-type building Excessive loads on their surface will first cause a puncture failure Cause only localized damage

Differential settlement and frost heaving do not pose severe problems DL and LL stresses are transferred to the supporting ground, spreading uniformly along the perimeter of a dome or bearing wall A dome or bearing wall built on a floating foundation, the base isolated by a layer of gravel or sand, provides the ideal earthquake-resistant structure.

The continuous or ring foundation can slide across the moving ground while the upper structure, which diminishes exponentially in mass toward the apex performs as a unified monolithic piece eliminating local failure higher up the building.

THERMAL PERFORMANCE R-value: ability of a structure or material to resist heat loss U = 1/R, where U= coeff of conductivity U value measures a material’s ability to store and transfer heat Earthen walls fn as an absorbent mass that is able to store warmth and re-radiate it back This temperature fluctuation is known as the “thermal flywheel effect”

Thermal performance is regulated by Effect of flywheel is a 12 hr delay in energy transfer from exterior to interior At hottest time of the day the inside of earth bag structure is at it’s coolest, while at the coolest time of the day the interior is at it’s warmest Thermal performance is regulated by placement and condition of windows and doors climatic zone wall colour wall orientation wall thickness 12 hr delay is only possible in walls greater than 30cm thick

EMERGENCY SHELTER shelters can be built using only dirt with no cement or lime Local resources can be used with ease windows can be punched out later simplicity of construction Labour can be unskilled high physical strength or formal training is unnecessary for the workers

so women and children are able to substantially contribute to the construction process temporary structure cover it with waterproofing and stucco, it will last for 30 or more years

SUSTAINIBILITY Realized as a green building technique System is extremely cheap and easy to build Soil can be taken right from the site, and the bags can be obtained for free or for a low cost Technique demands few skills Building technique is accessible to low income communities Building can be erected very quickly System is very flexible, allowing for alterations in design and construction

Major ingredient is earth, which is nontoxic and readily available In terms of energy conservation, the walls are very thick and have significant thermal mass, which reduces heating and cooling costs Provides sound insulation, structural integrity, fire resistance, and protection against pests

NEW APPROACH TO SAND BAGS SAND BAG CONSTRUCTION SUPERADOBE CONSTRUCTION No tensile capabilities Very low in height Curved, arched or domed structures were impossible Low shear capabilities Temporary structure Potential deterioration Develop tensile and shear capabilities Creates the capability of designing higher walls and curved surfaces Permanent structures are possible More durable

ADVANTAGES Earth quake safe

Fire proof

Wind proof Flood control User friendly Easy to learn Most of bldg material is free, local and used without harm to the environment

DISADVANTAGES It does take a lot of people to build a house by hands only It gets difficult after several hours of lifting the heavy bags   It isn’t easy to understand at first when you look at the way it is being built   It takes strength to lift and carry each bucket No mention of them in building codes High moisture content and dampness cause serious problems

Chili

India

Brazil

CONCLUSION Inexpensive Natural, reversible, recyclable building materials no harmful to our health and the environment Low energy input and environmental pollution small waste production Economic and environmentally friendly Statically strong, durable, and resistant even to extreme  weather conditions and natural catastrophes (flood, windstorm, hurricane, fire, earthquake) Reduce global warming Speed in construction