FRC thin walled structures: opportunities and threats

Author(s): M. di Prisco, M. Colombo
Paper category: Conference
Book title: 8th RILEM International Symposium on Fiber Reinforced Concrete: challenges and opportunities (BEFIB 2012)
Editor(s): Joaquim A.O. Barros
Print ISBN: 978-2-35158-132-2
e-ISBN: 978-2-35158-133-9
Publisher: RILEM Publications SARL
Pages: 23 - 49
Total Pages: 27
Language: English

Abstract: 
FRC thin walled structures represent a challenge for the future constructions. The interest in this topic is connected to design of very light roofing and retrofitting of façade systems. The former structures are often prefabricated and usually are longitudinally prestressed in bottom chords, where steel is protected also by fire attacks, and fibres can substitute partially or totally diffused transverse reinforcement, traditionally made of welded steel fabric. These structures are subjected to in plane and out of plane stress states and often they are designed to fail in longitudinal bending. Material innovation offers to modern designers also the challenge of multilayer structures made of advanced cementitious composites. When HPFRCC is used, a significant residual strength in uniaxial tension after cracking is available. Textiles can be coupled to HPFRCCs to stabilize crack propagation, but for fibre amount not exceeding 1.5% by volume, the peak behaviour in uniaxial tension is not significantly changed by steel fibre addition, while the post-peak behaviour grows linearly with fibre amount. A suitable fibre orientation can improve the tensile behaviour along the flow direction, but in any case this improvement is always associated to a significant strength loss in the direction cast at right angle. The paper first presents the conceptual design of thin-walled elements made of FRC, then the mechanical characterization taking into account the effect of the reduced thickness and fibre orientation. Finally some special problems like size-effect, both in tension and in compression, fire resistance and instability are analysed to reasonably predict the serviceability and ultimate bearing capacity, when a thin-walled open-profile cross section or a composite layered structure are considered.

Online publication: 2013
Publication Type: full_text
Public price (Euros): 0.00