In this work, basic guidelines are provided for the design of a polypropylene-based fiber reinforced concrete (PFRC) road pavement, as applied in an actual testing section resting inside a tunnel of the “Quadrilatero Marche-Umbria” road empowerment project, Italy. Results of a six-month monitoring carried out on actual traffic loads are also presented, as a feedback to the designing stage. Monitoring encompasses direct measurement of the strain level inside the cast as well as acoustic measurement. It is shown that the fiber reinforced concrete technology provides an efficient, safe as well as cost-effective design solution for roadways, especially inside tunnels

HPFRC/UHPC are today widely applied as repair and reinforcement materials for structures. One of the\ud drawback of commercial HPFRC/UHPC is that any modification of the matrix-fibers mix design, due to the\ud market requirements, affects the mechanical properties of the hardened concrete and therefore the data obtained\ud testing the previous version of the concrete are useless. Prediction models that link the properties of bothfibers\ud and matrix to the performances of the hardened concrete are of great practical interest. This paper present a\ud simple and effective model to account for the effect offibers on the compressive and tensile strengths of HPFRCs\ud as the aspect ratio and volume offibers changes, extending the range of application of the few existing models

This paper deals with the equilibrium problem in nonlinear elasticity of hyperelastic solids under anticlastic bending. A three-dimensional kinematic model, where the longitudinal bending is accompanied by the transversal deformation of cross sections, is formulated. Following a semi-inverse approach, the displacement field prescribed by the above kinematic model contains three unknown parameters. A Lagrangian analysis is performed and the compressible Mooney-Rivlin law is assumed for the stored energy function. Once evaluated the Piola-Kirchhoff stresses, the free parameters of the kinematic model are determined by using the equilibrium equations and the boundary conditions. An Eulerian analysis is then accomplished to evaluating stretches and stresses in the deformed configuration. Cauchy stress distributions are investigated and it is shown how, for wide ranges of constitutive parameters, the obtained solution is quite accurate. The whole formulation proposed for the finite anticlastic bending of hyperelastic solids is linearized by introducing the hypothesis of smallness of the displacement and strain fields. With this linearization procedure, the classical solution for the infinitesimal bending of beams is fully recovered.

The usage of a crystalline undulator (CU) has been identified as a promising solution for generating powerful and monochromatic [equation]-rays. A CU was fabricated at Sensors and Semiconductors Lab...

Anticlastic deformation (AD) is an established mechanical property of isotropic solid bodies, which has been recently used to steer particle beams through channeling in Si crystals. An analysis of AD in an anisotropic material, such as Si, has been worked out with particular emphasis to the cases used in channeling experiments. Both a theoretical model and finite element simulations were developed and compared to experimental data achieved by optical profilometry on bent Si crystals. A quantifier of the extent of AD, namely the ratio between primary and secondary curvature radii, has been found to be orientation dependent and determined analytically. The realistic case of crystal bending by a mechanical holder has been studied for applications. We addressed the case of the holder with a crystal at the energy currently under operation in the CERN super proton synchrotron and its possible extension to higher energy cases such as for the large hadron collider. Anisotropy-driven torsion of the crystal was investigated, determining a limitation to the portion of the crystal suitable for channeling. The geometry of the jaws clamping the crystal was considered too.