The enhanced toughness of Fiber Reinforced Concrete (FRC) comes from the ability of fibers to carry stresses after cracking of the concrete matrix, improving the energy absorption of the material during fracture; this is mainly due to the pull-out mechanisms that occur between fibers and concrete matrix during the fracture process. The ability of FRCs to absorb energy is one of the most important benefits of using fibers into the plain concrete. Many tests have been developed to characterize the energy absorption capacity of FRCs using simple loading configurations such as compression, tension and flexure. The bending test is the most widely used because it is simple to be performed and it represents a typical service condition for structural elements. This paper shows the results of an experimental study based on flexural tests of concrete reinforced with steel and polyester fibres. Different volume fractions of fibers and water-cement ratios (a/c) were analysed in order to investigate their influence on the FRC’s toughness and workability. While the influence of the fiber type and the fiber content has been widely investigated, their combination with the influence of the a/c ratio of the matrix still requires further studies. The experimental program concerns compression tests and four point bending tests on notched specimens. Durability aspects concerning FRC structures will be also discussed. In particular, water permeability tests were performed on cracked and uncracked specimens in order to evaluate the influence of the fiber type, the fiber volume content and the crack opening on the permeability of the matrix.
Valutazione sperimentale delle caratteristiche di tenacità e durabilità di calcestruzzi fibrorinforzati con fibre di acciaio e sintetiche
VASANELLI, EMILIA;MICELLI, Francesco;AIELLO, Maria Antonietta;
2008-01-01
Abstract
The enhanced toughness of Fiber Reinforced Concrete (FRC) comes from the ability of fibers to carry stresses after cracking of the concrete matrix, improving the energy absorption of the material during fracture; this is mainly due to the pull-out mechanisms that occur between fibers and concrete matrix during the fracture process. The ability of FRCs to absorb energy is one of the most important benefits of using fibers into the plain concrete. Many tests have been developed to characterize the energy absorption capacity of FRCs using simple loading configurations such as compression, tension and flexure. The bending test is the most widely used because it is simple to be performed and it represents a typical service condition for structural elements. This paper shows the results of an experimental study based on flexural tests of concrete reinforced with steel and polyester fibres. Different volume fractions of fibers and water-cement ratios (a/c) were analysed in order to investigate their influence on the FRC’s toughness and workability. While the influence of the fiber type and the fiber content has been widely investigated, their combination with the influence of the a/c ratio of the matrix still requires further studies. The experimental program concerns compression tests and four point bending tests on notched specimens. Durability aspects concerning FRC structures will be also discussed. In particular, water permeability tests were performed on cracked and uncracked specimens in order to evaluate the influence of the fiber type, the fiber volume content and the crack opening on the permeability of the matrix.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
