An Indian-American researcher has helped develop a tough new ceramic material that is almost twice as strong as concrete and may be the key to providing high-quality, low-cost housing throughout the developing world.
Arun Wagh spent a decade at the Argonne National Laboratory here working on a ceramic material that offered the toughness of concrete. He finally developed a substance called ‘grancrete’, which can be used to quickly build houses at minimal expense.
"I was asked to create a material that could safely encase nuclear waste so that the waste did not get into ground water," said Wagh. The substance Wagh developed combined magnesium oxide and potassium phosphate with water and ashes.
The promising new technology may lead to affordable housing for the world’s poorest. Houses can be built by spraying grancrete on to a simple frame of Styrofoam and it hardens quickly and will not crack easily.
Experiments have proved that grancrete is stronger than concrete, is fire resistant and can withstand both tropical and sub-freezing temperatures, making it ideal for a broad range of geographic locations. It insulates so well that it keeps dwellings in arid regions cool and those in frigid regions warm.
"Grancrete is 50 percent sand or sandy soil, 25 percent ash and 25 percent binding material," Wagh said.
"Binding material is composed of magnesium oxide and potassium phosphate, the latter of which is a biodegradable element in fertilizer. So even if grancrete were to decompose, it would revitalize the soil," said the scientist.
"For every tonne of conventional concrete, you get a tonne of greenhouse gases. With one tonne of grancrete, you get one-tenth of the greenhouse gases."
According to an estimate by Casa Grande, the company that is collaborating with Argonne in making grancrete, the cost of building a grancrete home is about $6,000.
"Casa Grande made this estimate for building a house in Venezuela. In India, it would be much cheaper," said Wagh, whose goal is to see grancrete used throughout India, and the world, to produce housing for the poor.
In fact, a test house using grancrete is being built in India.
Wagh is familiar with the housing the poor live in. He grew up in a village in Karnataka where, even to this day, the homes have walls and ceilings made from knitted mats of palm leaves and the floors are made up of dried cow dung.
Grancrete is so versatile that Wagh even paints using it. "It becomes like a paste and you can add any colour to it… It is a little more difficult to use than oil paint.
"Every day I come to the office, I get a call from people telling me it can be used for something else. You can do anything with it. The only thing you cannot do is eat it," Wagh said.
Argonne and Casa Grande have extensively field-tested grancrete for structural properties, post application behaviour and production costs. Their next step will be to test it for both earthquake and hurricane resistance, after which they will make the product available worldwide.
According to Jim Paul, president of Casa Grande, workers need only two days of training to learn how to calibrate the machinery.
Casa Grande typically assembles a team of five people who can start in the morning and create a home that residents can move into that evening. Grancrete cures in 15 minutes, while conventional concrete can take hours, or even days, to dry.
Wagh completed his Masters in Mumbai and got a doctorate from the State University in New York. He returned to India, taught in Goa, and then spent 12 years in Jamaica.
In Jamaica, Wagh changed tracks from physics to materials science. Returning to the US, he joined Argonne as a materials scientist.