There are different ways to insulate and strengthen concrete walls. Forms of Polystyrene, for example, serve two purposes: creating a mold for concrete pouring and acting as an air barrier to better insulate your home. Natural materials, such as straw, also can improve the performance of concrete walls. Adding straw to the concrete mix before pouring helps reinforce the bonds between the aggregate and cement, and it creates air pockets that improve insulating properties like an air-entraining agent. The mixture also retains moisture, which slows the curing process and improves the final strength of the wall.
Put on the safety goggles, a breathing mask, thick gloves, a long-sleeved shirt, pants and shoes with reinforced toes.
Place the bale on a tarp or concrete surface.
Saw the bale into thirds with the chainsaw. Set aside two-thirds of the bale.
Cut through the remaining third of the bale with the chainsaw to divide the pieces into 4- to 6-inch lengths.
Transfer the bale pieces to a wheel barrow by hand. Cut the straw as you transfer it to ensure every piece is 4- to 6-inches long.
Mist the straw lightly with a hose to keep the pieces from flying away.
Pour concrete powder into a concrete mixer or wheel barrel.
Add straw gradually to the mix as you make concrete. Stir and incorporate one-third of the bale of chopped straw in to the mixture for every cubic yard of concrete mix.
Use a cup or bucket to add water in small amounts. Add just enough water to keep the concrete mixture pourable; too much water can weaken the concrete mixture.
Things You Will Need
- Safety goggles
- Breathing mask
- Long sleeves
- Long pants
- Strung bale of straw
- Water hose
- Heavy-duty scissors
- Concrete powder
- Concrete mixer or wheel barrel
- "Ultimate Guide to Masonry and Concrete: Design, Build, Maintain"; Creative Homeowner Press; 2006
- National Ready Mixed Concrete Association; What is Curing; 2000
- "Serious Straw Bale: a Home Construction Guide for All Climates"; Paul Lacinski, et al. ; 2000
- "Better Houses, Better Living: What to Look for When Buying, Building Or Remodeling"; Myron E. Ferguson; 2004
- U.S. Department of Transportation; Air-Entraining; 2011
- "Reinforced Concrete and the Modernization of American Building, 1900-1930"; Amy E. Slaton; 2001