However, Michelle Pelletier, a graduate student at the University of Rhode Island, has discovered a way for concrete to heal itself.  Pelletier found that after fracturing concrete mixed with a microencapsulated sodium silicate agent into standard concrete can cause the concrete to regain up to 26 percent of its original strength.  It is speculated that a higher concentration of the sodium silicate will result in a higher rebounding strength.

After the concrete fractures, the sodium silicate particles break apart and mix with calcium hydroxide (a standard agent in concrete).  The mixture then forms calcium-silica-hydrate which fill the cracks.  This simple chemical reaction could lead to less potholes and longer road lifespans, and ultimately leading to saving more natural resources.

The best part about this is unlike most “smart” materials and technology.  This one is very cost effective and means that it could be implemented quickly and efficiently.

via uri.edu

image via imactlab.com

Fly ash is a waste product of a coal combustion plant.  It is the non-combustible portion of coal that used to be released into the air before through the smoke stack before the government put more strict regulations on what can be release into the atmosphere.  The particles themselves are spherical and smooth and more fine than cement particles.

When fly ash is added to concrete, it reduces separation,increases the workability, and reduces permeability.  Fly ash cement has greater corrosion resistance, substantially higher fire resistance (up to 2400° F), high compressive and tensile strengths, a rapid strength gain, and lower shrinkage.  This translates to higher durability.   The lifecycle of this kind of concrete can be measured in hundreds of years instead of decades.

There are over 600 fly ash dump sites in the US all of which can be turned into concrete.  This kind of concrete could save hundreds of acres of dump sites currently used for the disposal of coal combustion products, and could also protect water sources from being polluted as a result of fly ash leaching into water supplies.

via science daily and bulkgroup

1.  Make sure there is as little portland cement in the mix as possible.  Portland cement takes a lot of energy to produce, and thought the end product may be green, the process is not.

2.  Use industrial waste byproducts such as fly ash, slag cement, and silica fume.  This is all waste from steel mills, and coal-fired power plants.  These materials can also add wonderful color to the cement as well.  According to concretenetwork.com, fly ash makes cement  more durable, stronger and easier to work with.

3.  Use recycled glass and/or stone as aggregate substitutes.  This can also add a lot of visual appeal instead of having just a plain grey countertop.

4.  Consider using glass-fiber reinforced concrete or GFRC.  It uses far less portland cement than traditional concrete, and it has a lot of recycled material already in it.  Depending on the thickness it can be more expensive, however, since GFRC is stronger than traditional concrete, it can be poured to .75 to 1″ rather than the industry standard of 1.5-2″.  Less material is needed so the cost is comparable.

5.  Watch what goes on top of the concrete as well.  Make sure the sealer is not petroleum based.  There are many vegetable oil based products out there that to a wonderful job such as Bio-Release EF from Dayton Superior and Farm Fresh from Unitex.  There are also water-based sealers like V-Seal 101 (www.vseal.com) and Pro-Seal US II-A (www.prosealproducts.com) that are also environmentally friendly and, like the vegetable oil based sealers, will have very low VOCs.

via concretenetwork.com

image via truformconcrete