JEC COMPOSITES MAGAZINE - Issue #35 - September 2007 - 26

BUSINESS Trends Italian guidelines: on the use of innovative materials for structural purposes Those involved in research and design activities in the field of strengthening with fibre-reinforced polymer composites (FRP) consider that Italy is gaining a worldwide reputation, both for the value of its contribution to improving the knowledge in this field and for its significant building heritage, [1-6] which includes buildings of historical and architectural relevance and more recent structures in masonry, reinforced concrete, prestressed concrete, or steel. Most of the latter structures need structural rehabilitation. Externally Bonded FRP Systems for Strengthening Existing Structures – Materials, RC and PC Structures, Masonry Structures”, provides guidelines within the constraints of Italian regulations for the design and construction of externally bonded FRP systems for reinforcing existing structures [7-9]. It is important to highlight that a guideline is not a binding regulation, but merely an aid for practitioners interested in the use of composites. The document deals with the materials and basic concepts used in FRP reinforcement, including a summary of the many advantages and some disadvantages of FRP Specific guidelines . are also provided for the strengthening of reinforced and prestressed concrete structures and for masonry structures for constructions subject to earthquakes, in accordance with the most recent national and international design codes (Figures 1 & 2). An appendix presenting notions on the mechanical characterisation of composite materials is also included. FRPs in the rehabilitation of timber structures Document CNR-DT 201/2005, or “Guidelines for the Design and Construction of Externally Bonded FRP Systems for Strengthening Existing Structures – Preliminary Study. Timber Structures”, aims to inform the technicalprofessional community on the use of FRPs in rehabilitating timber structures and to identify safe, suitable reinforcement systems. This study is only a first step towards specific design guidelines, which should be forthcoming in the near future, once a more complete and universally accepted understanding of the subject is reached from ongoing theoretical and experimental studies world-wide. The most widespread application of FRPs is the reinforcement (primarily in bending) of timber elements such as single beams, floor beams, or individual components of more complex structural elements such as trusses and frames (Figure 3). Reinforcement can consist of laminae or sheets of various materials, applied according to those criteria offering the best advantages in terms of strength, deformability and ductility. Another use is the reinforcement of structures subjected to in-plane forces. A typical application is timber or mixed floors. Such structures, quite widespread throughout many European countries, L. ASCIONE & A. GIORDANO DEPARTMENT OF CIVIL ENGINEERING, UNIVERSITY OF SALERNO, ITALY T he Italian National Research Council (CNR) has been pushing for a series of guidelines on the structural use of innovative materials, and in particular for the design and construction of externally bonded FRP systems for reinforcing existing structures. Italy’s Advisory Committee on Technical Recommendations for Construction approved the first of these technical documents, No. 200/2004, as a draft version on July 13, 2004. Following incorporation of the modifications derived from the public hearing, the document was approved as a final version on April 26, 2005. Four additional documents were eventually licensed by the CNR. Materials and basic concepts of FRP strengthening Document CNR-DT 200/2004, or “Guide for the Design and Construction of Fig. 1: FRP-reinforced Fig. 2: FRP reinforced beam/column joint. vault. JEC Composites Magazine / No35 September 2007

JEC COMPOSITES MAGAZINE - Issue #35 - September 2007

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #35 - September 2007