Dec 7 2015
Meetings in Paris this week on the climate brought forth a call for more environmentally friendly construction from a new alliance of nations and organizations, the Lima-Paris Action Agenda Focus on Building.
Rouzbeh Shahsavari (Photo by Jeff Fitlow/Rice University)
Rouzbeh Shahsavari, a Rice University materials scientist who studies concrete at the molecular level, confirmed that more careful thought about materials can bring about significant reductions in carbon emissions.
“When it comes to mega-urbanization imposed by a growing population, such infrastructure needs as concrete building, bridges and the like are necessary to meet the demand,” said Shahsavari, an assistant professor of civil and environmental engineering. “In this context, concrete always stands out as one of the primary material choices. However, the current manufacture of its key ingredient, cement, puts a doubt on the future of sustainable development to address climate concerns. We need to fundamentally rethink ‘cement’ in this age of global warming.”
Shahsavari said the annual worldwide production of more than 20 billion tons of concrete contributes 5 to 10 percent of carbon dioxide to global emissions, surpassed only by transportation and energy as a producer of greenhouse gas.
He recently showed that with a fundamental understanding of the behavior of defects in cement crystals, one can lower the energy consumption of cement production and its associated carbon dioxide emissions. “In light of the Paris talks, this approach may introduce one of the much-needed strategies to have a fresh look at the manufacture of this century-old infrastructure material,” he said.
In another study, he and colleagues at the Massachusetts Institute of Technology and Marseille University showed last year that fine-tuning concrete for specific types of construction can make the manufacturing process far greener.
“We learned that at any given calcium/silicon ratio, there are 10 to 20 different molecular shapes, and each has a distinct mechanical property,” he said. “This will open enormous opportunities for researchers to optimize concrete from the molecular level up for certain applications.”
Ibrahim Thiaw, deputy executive director of the United Nations Environment Program, noted at a press conference in Paris that buildings represent a third of global emissions and a third of energy and materials consumed worldwide.
“More than half the world’s population live in cities, and that will rise to 70 percent by 2050,” he said. “You can imagine the consequences of that on climate.”
Shahsavari is available for interviews. Contact Mike Williams, senior media relations specialist at Rice at [email protected] or at 713-348-6728.