Strengthening strategies and structural rehabilitation of existing buildings with innovative materials and techniques are today one of the main activities in the field of structural engineering. Externally bonded Fiber Reinforced Cementitious Matrix (FRCM), materials are spreading as an alternative strengthening technique to the more traditional Fiber Reinforced Polymer (FRP) ones, especially for masonry elements. This research focuses on the assessment of the shear strength of in-plane FRCM-strengthened masonry walls by means of code predictions and numerical results, with particular attention on the interpretation of diagonal compression tests simulated by means of Finite Element (FE) models. Firstly, the various approaches commonly adopted for the interpretation of diagonal compression tests in terms of shear strength were examined, since codes give generally provisions in terms of maximum shear force, while several experimental and numerical results of diagonal compression tests are available in literature. Then, the numerical simulations of diagonal compression tests obtained by several FE analyses in a previous work were examined in light of these different approaches; the corresponding predictions of the shear force are compared with code indications in order to individuate the most reliable approach both for the un-strengthened and the FRCM-strengthened walls. For the latter ones, a detailed analysis of the actual strain levels in the reinforcement was carried out, too, by means of FE analysis.

In the last decades Fiber Reinforced Plastic (FRP) have been widely adopted for strengthening and repair of damaged structures. Design indications about the use of FRP materials as external strengthening techniques for structures are available in Italy since 2004, while only in 2015 the Italian Ministry of Infrastructure and Transportation published Guidelines for the qualification of FRP products. This paper summarizes the results of several experimental activities for the qualification of preformed FRP products. Statistical analyses were carried out in order to provide indications on variability of FRP's mechanical properties and assess the reliability of the classes individuated by the Italian guidelines.

The present analytical work deals with the assessment of the performances of Reinforced Concrete (RC) Deck Arch Bridges under the non-seismic loading conditions required by the current mandatory Italian codes. In particular, the attention is focused on a specific RC deck arch bridge typology, better known as the "Maillart Type Arch Bridge", which is characterized by a very stiff deck beam and a slender and wide vault. As well as other existing RC structures which were designed under only gravity loads and without specific structural details, such as lower limits for longitudinal and transverse reinforcement bars, these bridges could be damaged by loading conditions not considered at the time of design. For the evaluation of the main critical issues related to the current performance of such bridges under the current non-seismic loading conditions, it has been defined a large inventory of simulated arch bridges in accordance to the design procedures usually adopted in 1950s which considered only gravitational loads, i.e. self-weight and moving loads. Each bridge of the inventory is modelled and studied by means of a Linear Gravitational analysis implemented in the structural software SAP2000, with support of an Application Programming Interface (API), such as Matlab. Due to the differences between the current loads and those considered at the design time and to the approximations of the design strategies of the time, a performancebased analysis of the existing bridges under non-seismic loads is important for the stakeholders as much as for the decisionmakers in order to plan risk mitigation programs and prioritize eventual retrofit interventions for risk reduction.

No abstract

The 20th century is known as the age that gave birth to the largest reinforced concrete structures. Many applications of this new material were realized at that time, both from a theoretical and practical point of view. With reference to bridges, the engineer Robert Maillart achieved a new concept of arched bridges, characterized by very stiff deck beams and slender and wide vaults, i.e., the "Deck-Stiffened Arch". The paper deals with the study of such bridge typology, particularly widespread in Italy around the 50s of the 20th century. While, nowadays, calculation tools allow developing very refined structural modelling, in the past very simple structural schemes were adopted in the design phase in order to simplify the calculation effort. The study starts from a "simulated design" of such a bridge typology adopting a reliable geometry and following the design rules and the simplified structural schemes of the time and, then, by means of a refined three-dimensional model, the performance of a typical "Maillart-Type Arch" bridge is analysed.