Surveying the damage:a concrete building that collapsed in the earthquake
Flickr/United Nations Photo
Straw and rubber tyres are among the materials being considered for the rebuilding of Haiti's cities, devastated in last month's (January) earthquake.
Many Haitians are still living outside so the country needs quick, cheap solutions for housing its citizens in earthquake-proof buildings.
Darcey Donovan, founder of the non-profit organisation Pakistan Straw Bale and Appropriate Building, suggests constructing buildings from straw bales instead of concrete which, while cheap, is heavy and brittle — a bad combination in an earthquake. Such straw houses withstand severe shaking in tests (see Straw house design passes earthquake tests).
Others say that concrete can still be used in a safe way. James Kelly, professor emeritus of civil engineering at the University of California, Berkeley, in the United States, suggests erecting buildings on rubber foundations to absorb shocks, as in Japan.
Recycled rubber tyres can be used for this, says John van de Lindt, a civil engineer at Colorado State University. And inserting bamboo buttresses into concrete walls would further reinforce them, he adds.
"This isn't sophisticated science," acknowledges van de Lindt.
But Haitians need to accept the new designs and building techniques — and quickly.
Haitian earthquake engineer Pierre Fouché says: "If nothing is done quickly … people there are going to do the same thing [as before]. They think, 'a big earthquake just happened so there isn't going to be another one for a while'."
Link to full article in Science
Comments (3)
PABLO KORACH
(
Chile
)
8 February 2010
Good morning: Reading scientist advvise about reconstruction in Haiti to use straw bales to build the homes is excellent but wood is better.There is a new technolgy called the HOLLOW BEAM that would be perfect for the following reason: 1)the low cost of this material 2)It could be rapidly supplied 3)The Haitians can help to buid their own homes and get paid for it as they learn from the carpenters from overseas 4)These homes, the way they are built will probably move as a whole but cannot be destroyed by an earthquake Last but not least these homes are green ,not because of the additions but for the fact that the Hollow beam only needs half of the volume of logs (trees) that are needed compared with today system using solid lumber best regards Pablo Korach Engineered wood prods M.A.Sc.Chemical Eng
Robert Miller
(
United States of America
)
8 February 2010
I have lived in California and Central America have constructed buildings in both areas in earthquake zones. Concrete block is inflexible, and so is the very poorest choice of building materials in such zones. In Quito, Ecuador, there is a modular home project using cast cement panels--again, poorly suited for fault areas. Earthquake zones require buildings that can move and flex without coming apart. The best in California appear to be of wood construction. However, since Haitians have cut down and burned for fuel most of their timber, lumber is at a premium and is not a possible choice. For a time there was an experiment in Honduras with the construction of cast poly foam panels, but this was short-lived because it depends on the importation of processed petrochemicals. The traditional use of adobe and straw commonly used elsewhere requires shelter from inclement rains to prevent the walls from literally melting, but may be the most economical choice for a country as impoverished as Haiti. Developed countries must resist the temptation of importing inappropriate materials that do not use existing resources and which require technologies that require electricity, expensive fabrication equipment, and are oil-based. USAID would be wise to look to the homes of native peoples in New Mexico and build upon the wisdom that has endured for centuries.
Don Miller
(
Vanuatu
)
9 February 2010
A further possibility is to use leaves for thatching roofs. Vetiver grass (Chrysopogon zizanioides) is a deep rooted conservation species that has great potential to stabilise the hill slopes of Haiti. It also provides large quantities of leaves that have been used as a long lasting thatch in a number of countries, most recently in Senegal, Ethiopia and Mexico, but also last century in Fiji and New Caledonia. The thatch being of relatively light weight, bamboo, if available, could be used for roof beams. Bamboo is used as beams quite satisfactorily in traditional Vietnamese houses with their much heavier tiles. Don Miller, Vanuatu
16 February 2012