Carbon Nanotubes and Cement

In class the other day, while working in the library, I found an interesting study done that I was actually curious about (which can be founder here). I was curious about how the use of carbon nanotubes would effect flexible concrete. This conducted test measured multiple different strengths with multiple different forms of carbon nanotubes and was able to show that they actually do increase the strength within a cement mixture, a key part in concrete and flexible concrete. The amazing thing about carbon nanotubes is just how ridiculously small they are. As seen within the study, images were taken of the various forms of nanotubes tested and have to be referenced on the micrometer scale. That's .000001 meters or 1/39360000". Due to their size and tested strengths, they are a material that has one of the highest strength to weight ratios ever recorded. The only issue is that they, currently, can only be made to be extremely short in length, short enough that the nanotubes can still be measured in that micrometer scale. This also leads to an economical issue since the production of these ridiculously small objects tends to be very expensive. Hopefully one day they won't be and who knows what can come of this relatively new material. I'm looking forward to seeing if there is a way to make the nanotubes possible on the economic side in my next bout of research because, as seen in the conducted study, they worked extremely well on the strength side.