de la Fuente, A.; de Figueiredo, A.D.; Aguado, A.; Molins, C.; Chama, P. IBRACON structures and materials journal Vol. 5, num. 1, p. 12-25 DOI: 10.1590/S1983-41952012000100003 Data de publicació: 2012-01 Article en revista
This paper is part of an extensive work about the technological development, experimental analysis and numerical modeling of steel fibre reinforced concrete pipes. The first part (“Steel fibre reinforced concrete pipes. Part 1: technological analysis of the mechanical behavior”) dealt with the technological development of the experimental campaign, the test procedure and the discussion of the structural behavior obtained for each of the dosages of fibre used. This second part deals with the aspects of numerical modeling. In this respect, a numerical model called MAP, which
simulates the behavior of fibre reinforced concrete pipes with medium-low range diameters, is introduced. The bases of the numerical model are also mentioned. Subsequently, the experimental results are contrasted with those produced by the numerical model, obtaining excellent correlations. It was possible to conclude that the numerical model is a useful tool for the design of this type of pipes, which represents an important step forward to establish the structural fibres as reinforcement for concrete pipes. Finally, the design for the optimal amount of fibres for a pipe with a diameter of 400 mm is presented as an illustrating example with strategic interest.
de Figueiredo, A.D.; de la Fuente, A.; Aguado, A.; Molins, C.; Chama, P. IBRACON structures and materials journal Vol. 5, num. 1, p. 1-11 DOI: 10.1590/S1983-41952012000100002 Data de publicació: 2012-01 Article en revista
This paper is the first part of an extensive work focusing the technological development of steel fiber reinforced concrete pipes (FRCP). Here is presented and discussed the experimental campaign focusing the test procedure and the mechanical behavior obtained for each of the dosages of fiber used. In the second part (“Steel fiber reinforced concrete pipes. Part 2: Numerical model to simulate the crushing test”), the aspects of FRCP numerical modeling are presented and analyzed using the same experimental results in order to be validated. This study was carried out trying to reduce some uncertainties related to FRCP performance and provide a better condition to the use of these components. In this respect, an experimental study was carried out using sewage concrete pipes in full scale as specimens. The diameter of the specimens was 600 mm, and they had a length of 2500 mm. The pipes were reinforced with traditional bars and different contents of steel fibers in order to compare their performance through the crushing test. Two test procedures were used in that sense. In the 1st Series, the diameter displacement was monitored by the use of two LVDTs positioned at both extremities of the pipes. In the 2nd Series, just one LVDT is positioned at the spigot. The results shown a more rigidity response of the pipe during tests when the displacements were measured at the enlarged section of the socket. The fiber reinforcement was very effective, especially when low level of displacement was imposed to the FRCP. At this condition, the steel fibers showed an equivalent performance to superior class pipes made with traditional reinforced. The fiber content of 40 kg/m3 provided a hardening behavior for the FRCP, and could be considered as equivalent to the critical volume in this condition.
Toralles-Carbonari, B.; Pialarissi Cavalaro, S.H.; Mendes, J.; Guacelli, P.; Catiste, C. IBRACON structures and materials journal Vol. 3, num. 4, p. 494-511 Data de publicació: 2010-12 Article en revista
This main objective of this research is to evaluate the variability of the mechanical properties (compressive strength, modulus of elasticity
and tensile strength) and bond strength of the self-compacting concrete (SCC), with 50 MPa compressive strength at 28 days, varying
the maximum aggregate size and the SCC fluidity. The tests were made in 15 x 30 cm concrete cylinders and in beams standardized by
Rilem-Ceb-Fib (1973). In agreement with the obtained results, can be concluded that the variability of the self-compacting concrete is
small for the modulus of elasticity and for the compressive strength, but the tensile strength presented a significant variability due to the
failure mode. About the bond strength, the variability was small showing that the self-compacting concrete is reliable and possesses great potential for use in the civil construction.