By Stephen Markley on June 2, 2010
That’s the idea behind University of Rhode Island grad student Michelle Pelletier’s concrete concoction. By mixing a microencapsulated sodium silicate agent into normal concrete, Pelletier created a road material that can regain 26% of its original composition after being fractured.
When the concrete tears or breaks, the sodium silicate capsules break as well, releasing a catalyst that mixes with the normal concrete component of calcium hydroxide. This forms a calcium-silica-hydrate that fills in the cracks, strengthening the material.
Pelletier achieved the 26% strength regeneration with only a 2% solution of sodium silicate, and she believes a higher concentration could lead to even better results.
Pelletier also says her solution is relatively inexpensive; cost is usually the major downside to “smart” building materials. If the solution could pay for itself by saving municipalities road-repair funds, it could be rapidly adopted by penny-pinching state and local governments.