Non Finito: Challenges in Rehabilitation

Abstract

“Non Finito” is a sculpting technique literally meaning that the work is unfinished. Non finito sculptures appear unfinished because the artist only sculpts part of the block, leaving the figure appearing to be stuck within the block of material. The idea of post-strengthening civil structures with carbon fiber reinforced polymer (CFRP) tapes was for the first time unveiled in an oral presentation at ETH Zurich in 1985. An appropriate feasibility study was published 2 years later. The reactions of the listening and reading audience were mixed. Most found the concept very crazy and absolutely not practicable. The method is meanwhile state-of-the-art. The goal of this paper is to discuss the very promising system of CFRP straps as active external reinforcement in present time and to list three examples of new “crazy” ideas which might be interesting for future R&D work and might show successful applications in 10, 20 or 30 years. (i) More and more lacy and very slender structural components of historic structures like in the matter of the dome of Milan are suffering cracking. Internal, post-tensioning along three-dimensional boreholes with thin CFRP wires could be powerful tool to close the cracks. (ii) After all the severe earthquakes within the last few years seismic retrofitting gained dramatically relevance. CFRP post-strengthening is a successful mean in many cases however not always applicable. For example in the case of a mosque with golden mosaic ceilings there is no possibility to adhere black CFRP strips to the surface. Why should we not work with huge airbags, corresponding gas generators and sensors? How could we avoid that such airbags kill people? (iii) In modern architecture it is more and more fashionable to design and construct lean high raised towers. Already in the past some of them faced oscillation problems due to aerodynamic excitations. Instead of the subsequent installation of tuned mass dampers an adaptive outer skin made of electro-active polymers might resolve this problem. “Non Finito” in this paper means only to sculpt ideas and leave the realization to the next generation of researchers and engineers.