I think I’m going to have a Science Cafe NH later this year on the topic of building materials and carbon sequestration. I suspect most of it will cover modern lumber technology like cross-laminated timber, since we have so many trees, but I’d like to find a panelist to talk about efforts to improve the carbon-intensive production of making concrete.
The Union-Leader ran a Bloomfield article about one of those efforts: adding hemp to the cement that is used to make concrete. (Article is here)
Cement makers are responsible for about 7% of global carbon dioxide emitted into the atmosphere every year, with copious volumes entering via limestone kilns needed to produce the material.
While architects and developers have traditionally concentrated on the energy used by their buildings once they’re are standing, it’s actually the materials required in their construction that represent the brunt of a structure’s lifetime carbon footprint. Replacing high-carbon-intensity materials like cement with greener alternatives like hemp can dramatically reduce greenhouse gas pollution.
Hemp fields absorb carbon when they’re growing. After harvest, the crop continues to absorb greenhouse gases as it’s mixed with lime or clay. Hempcrete structures also have better ventilation, fire resistance and temperature regulation, according to their proponents.
Cement is an ingredient in concrete. The same way flour is an ingredient in bread.
I know that one is an ingredient in the other but for some reason I can’t keep it in my head which is which. Both starting with “C” and having two syllables probably doesn’t help.
When I think ‘cement’ I think of glue like when building models as a kid. Cement sticks stuff together, like the other components in concrete.
When I think ‘concrete’ I think of hard rocky stuff like sidewalks, driveways, and buildings.
David , Think of concrete as creating. Making an amalgam, so cement is an ingredient.
You should connect with Saint Gobain, the building materials company. They do a lot of work with us at Greentown Labs in Somerville, MA and have a large presence in NH.
Thanks. I’m familiar with their crystal-growing plant in the Souhegan Valley but that’s all I know.
forget adding it to cement!
build with hemp itself!
The Incas made bridges out of long fibers woven together, so maybe …… it would require quite a change to building codes, however.