CEE civil engineers have for the first time identified what causes the most frequently used building material on earth — concrete — to gradually deform, decreasing its durability and shortening the lifespan of infrastructures such as bridges and nuclear waste containment vessels. In a paper published in the Proceedings of the National Academy of Sciences (PNAS) online Early Edition the week of June 15, Professor Franz-Josef Ulm and recent graduate Matthieu Vandamme say that concrete creep (the technical term for the time-dependent deformation that occurs in concrete when it is subjected to load) is caused by the rearrangement of particles at the nanoscale. Read more.