عنوان مقاله [English]
This research aims to introduce an optimized design with minimum possible fiber content while having the maximum possible energy absorption capacity. A series of laboratory tests were conducted with various additive and fiber contents to reach this goal. General recommendations for achieving the optimized results were proposed based on the experimental results. Beam and panel tests were used to account for energy absorption capacity.
Due to the relevance of the energy absorption capacity of fibrous concrete, several entities have been proposed for evaluating this property that include the toughness indices, the equivalent flexural strength and the fracture energy. Among these entities, the fracture energy is the most used in the constitutive models for characterizing the concrete tensile post-cracking behavior. The other entities have not been widely used in numerical simulation of the behavior of Fiber-Reinforced Concrete (FRC) structures. The generic mechanical response contains a linear regime, in which very little permanent micro-structural changes and deformation take place, and a nonlinear regime, in which permanent micro-structural changes occur in a stable manner.
Methodology and Approaches
In order to obtain the most appropriate mix characteristics with the highest energy absorption, an experimental study using 33 beam and rectangular panels was performed by the author. Tests were conducted for various fiber contents and the maximum specific absorbed energy was measured. The small amount of energy absorbed by plain concrete panel was ignored.
Results and Conclusions
The experimental study performed for finding optimized mix design of fiber reinforced concrete showed that applying some changes to the mix design, we can reduce the amount of fiber while keeping the energy absorption capacity constant. This totally results in a high performance of self-compacting fiber reinforced concrete with rather high strength and high energy absorption capacity. Such composite shows high resistance and ductility and can be excellent for both normal and special structural applications. Higher energy absorption levels may also be obtained by following a similar procedure as was performed in this study. Note that, although more fibers result in more energy absorption up to a certain level, the failure mechanism and structural behavior do not change, and thus, the same objectives can be met by using minimum amounts of fibers.