1,720,975 research outputs found
Bending and uni-axial tensile tests on concrete reinforced with hybrid steel fibers
No full textBased on the idea of taking simultaneous advantage of the effects of different types of fibers, new materials called hybrid fiberreinforced concretes have been developed by combining fibers of different geometry and material. In the present paper, the benefits in terms of concrete toughness from a combination of micro- and macrosteel fibers are evaluated under both bending and uniaxial tensile tests on specimens of different sizes. Experimental results are very sensitive to the strain gradient in the cracked section, to the fiber geometry and to the area of the cracked surface. In fact, a larger scatter in the experimental results was observed in specimens with smaller cracked surfaces where a greater variation of the macrofiber density occurred. For this reason, beside the size effects, the fiber size and the dimension of the cracked section markedly influence the characteristic value of the fracture parameters. A numerical simulation based on nonlinear fracture mechanics of the experimental test was carried out in order to better identify the fiber contribution in the fracture propagation.
Steel fiber concrete slabs on grade: a structural matter
No full textAn extensive experimental investigation with the aim of studying the structural behavior of slabs on ground made of steel fiber- reinforced concrete (SFRC) is presented in this paper. Several full- scale slabs reinforced with different volume fractions of steel fibers having different geometries were tested under a point load in the slab center. A hybrid combination of short and long fibers was also considered to optimize structural behavior. Experimental results show that steel fibers significantly enhance the bearing capacity and the ductility of slabs on ground.
The nonlinear behavior of these SFRC structures is well captured by performing nonlinear fracture mechanics analyses where the constitutive relations of cracked concrete under tension were experimentally determined. Finally, from an extensive parametric study, design abaci and a simplified analytical equation for predicting the minimum thickness of SFRC slabs on ground are propose
Steel Fiber Concrete Slabs on Ground: A Structural Matter
No full textAn extensive experimental investigation with the aim of studying the structural behavior of slabs on ground made of steel fiber-reinforced concrete (SFRC) is presented in this paper. Several full-scale slabs reinforced with different volume fractions of steel fibers having different geometries were tested under a point load in the slab center. A hybrid combination of short and long fibers was also considered to optimize structural behavior. Experimental results show that steel fibers significantly enhance the bearing capacity and the ductility of slabs on ground. The nonlinear behavior of these SFRC structures is well captured by performing nonlinear fracture mechanics analyses where the constitutive relations of cracked concrete under tension were experimentally determined. Finally, from an extensive parametric study, design abaci and a simplified analytical equation for predicting the minimum thickness of SFRC slabs on ground are proposed
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