Further thoughts from Dr. Edwards (again via Andy Price) on the Pugno study:  

“The supportive interaction between the CNTs already exists in several forms:
1) van de Walls forces
2) physical “knotting” or twisting like cotton or any other fiber and
3) functionalized nanotubes

Any one of these could be used to cross link CNTs and effectively transfer loads and greatly reduce the overall strength reduction of any weak CNT.  There are a couple other options as well, but these have been shown to work.  By not including this in a discussion of a macroscopic material, Pugno is insuring that the material will fall apart.  Compare a raw mat of cotton to a spun cotton thread – the performance is a little different.  I can assure everyone that raw cotton fibers are not perfect throughout their length (much less so than quality CNTs) but strong threads can still be made from them.”