Honors Project Researches Quake-Proof Building Material
First Class cadet Donnie Martin has drawn upon his family’s background in missionary work and added in his own aptitude for engineering to come up with a construction proposal that could someday save thousands of lives in earthquake-prone areas.
Martin, a civil engineering major who graduated from high school in Richmond, Va., spent many of his formative years overseas thanks to his father’s employment with the International Mission Board of the Southern Baptist Convention.
From the age of 3 on, Martin lived in England while his father worked in Africa. Additional postings in Singapore, Cyprus, and Turkey followed. The Martins, including 8-year-old Donnie, were in Cyprus when a severe earthquake struck Turkey in August 1999, killing more than 17,000 people. Both of Donnie Martin’s parents were involved in the relief efforts.
At VMI, Martin began to wonder if there couldn’t be a way to save lives in earthquake-prone developing countries, where steel is too expensive to use as reinforcement in building construction and most earthquake-related fatalities result from people being crushed by falling walls.
Martin approached Maj. Matt Swenty, assistant professor of civil and environmental engineering, about undertaking research for an honors thesis on the use of ferrocement as a laminate over existing structures. Ferrocement is a type of reinforced concrete that has been used for over 100 years as a primary building material, but as Martin and Swenty did their research, they could find no reference to it being used for retrofitting an already finished building.
“This began as looking for concrete enhancements for developing countries,” said Martin, who hopes, after graduating from VMI, to work in civil engineering research and then attend graduate school.
To test the potential for ferrocement’s use as a laminate, Martin took cinderblock structures and coated them with ferrocement. For additional reinforcement between the ferrocement and the cinderblock, Martin tried chicken wire, steel welded mesh, bamboo, and burlap, to simulate the kinds of materials that might be commonly used in different regions of the world.
When he subjected the four types of structures to a compression test, Martin found that two of the cheapest and most commonly available materials – bamboo and burlap – held up best.
“Chicken wire and steel mesh both snapped, but then the bamboo and burlap just kept stretching and stretching and never gave way fully,” Martin explained.
For slum dwellers, Martin believes, retrofitting their existing homes would be invaluable, as these people can’t afford to move, nor can they afford to replace their homes if they become uninhabitable. Applying ferrocement to an already existing structure is a labor-intensive process, Martin and Swenty explained, but labor is cheap in the developing world.
“If we could provide a coating, something that’s more ductile, so that it bends more, … we could create a structure that could withstand a little more load from either a hurricane or an earthquake,” said Swenty. He added that buildings in developing countries typically cannot withstand the effects of even a minor earthquake, because structures there aren’t reinforced at all.
“[Martin] has come across a great thesis topic for a master’s or Ph.D.,” noted Swenty, whose specialty is concrete and bridge engineering. “If we really wanted to push this to the implementation stage, we would need to do some more larger-scale testing. … Donnie proved through his testing last summer that not only is the concept there, but the concept is viable.”