Views:0 Author:Site Editor Publish Time: 2020-04-30 Origin:Site
When I think of concrete buildings, I think of dense, heavy concrete with a high environmental impact: Cement manufacturing accounts for 5 percent of global CO2 emissions from human activity, a staggering total for one building material. But utilizing more environmentally-friendly alternatives, such as Eastland autoclaved aerated concrete (AAC) blocks, AAC panels, does offer many benefits.
Chemical reactions with gases make autoclaved aerated concrete a lighter, more insulatied and fire-resistant alternative to concrete. AAC blocks and panels can also be molded and cut into dimensional units. Generally, they're more popular in post-war Europe than in the US - and they have been widely used in the UK and Germany.
AAC blocks are 80 percent air and 50 percent lighter than clay blocks of the same size, meaning they require less energy than concrete to transport. Compared to concrete AAC is also easier to cut and shape, boosting design flexibility and reducing waste with more accurate cutting.
AAC blocks are insect - and rot-resistant, and they are not destroyed by floods, according to the Portland Cement Association. These attributes are especially appealing in humid climates, and the use of AAC blocks can help reduce or eliminate the use of drywall or wood, preventing mold issues. The blocks are also sound resistant, and because they are non-combustible, they do not give off toxic fumes in a fire.
The R-value is similar to a typical stick frame house, but the blocks have a greater thermal mass - making the home more resistant to changing temperatures. This seems like a light improvement over many code-built homes on the market, but AAC blocks alone don't make a house ultra energy efficient.
Drawbacks to AAC
Because AAC contains concrete, it does have some of the same environmental drawbacks of concrete - but to a lesser extent because less cement is used to make the product. AAC is more expensive than concrete blocks, thus some builders mix use of both tradtion cement and AAC.
Fly ash in concrete raises concern
As much as 30 percent of the concrete can be replaced by fly ash, a hazardous coal combustion byproduct from coal power plants. This practice is praised by many industry groups and criticezed by some environmentalists, who call it the new asbestos.It does raise safe handling and health concerns from production to end-of-life disposal.