High performance steel fibre reinforced concrete: residual behaviour at high temperature

Autor: Matteo Colombo, Alessio Caverzan, Barbara Rivolta, Marco di Prisco
Rok vydání: 2014
Předmět:
Zdroj: Materials and Structures. 48:3317-3329
ISSN: 1871-6873
1359-5997
DOI: 10.1617/s11527-014-0401-9
Popis: Steel fibre reinforced concrete (SFRC) is considered as a profitable replacement for diffused reinforcement like welded steel mesh, especially for thin cross sections. In case of precast light roof elements, fire becomes a very important condition in the design. A previous experimental programme showed the benefits of steel fibre for fire resistance of bent members when macro-fibres (\(l_{\rm f}= 30\) mm; \(l_{\rm f}/d_{\rm f}=\) 45) are used with reduced contents (content by volume of 0.6 %). The interest to reduce the weight and to prevent the need of any water proofing membrane has suggested to use fibre reinforced high performance material. The material selected was also chosen self-compacting in order to be able to orient straight steel micro-fibres (\(l_{\rm f}= 13\) mm; \(l_{\rm f}/d_{\rm f}=\) 81) in the best direction just controlling the casting flow direction properly. The fibre content selected is equal to 100 kg/m3 (content by volume of 1.2 %), regarded as a minimum quantity to guarantee a safe hardening behaviour for thin elements in direct tension. The material has a cylindrical compressive strength of about 110 MPa. An experimental programme on prismatic specimens has been planned to investigate the behaviour of high perfomance cementitious composite reinforced by micro-fibres, when exposed to high temperatures. A third point bending set-up was adopted. The mechanical characterization was performed after thermal cycles up to three different thermal thresholds (200, 400 and 600 °C). Each thermal cycle was carried out in an electric furnace, by imposing a heating rate of 50 °C/h up to the maximum temperature, a two hours of stabilization phase, and a subsequent cooling at 25 °C/h. The tests confirmed the material as hardening in bending up to 400 °C. Moreover, the behaviour of the fibres were studied testing them at the same thermal damage level.
Databáze: OpenAIRE
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