Il comportamento flessionale di elementi sottili in HPC

The bending behaviour of thin HPC structural elements is governed by high compressive strength and by the possible presence of fibres, which significantly affect the post-cracking tensile behaviour. Although various types of fibres are produced for concrete, the metallic ones are the most interesting with reference to mechanical aspects. In Civil Engineering applications the content by volume is limited to 1% (78 kg/m3) for economical reasons. After an introduction on the most attractive applications in this framework, several examples are discussed in order to check fibre efficiency, which is strictly connected with the degree of structural redundancy. Then, the mechanical characterisation, starting from the choice of the constitutive model in uniaxial tension and the definition of design generalised stresses, is investigated. Finally some advanced problems on size-effect and instability are briefly discussed.