Thereby, the maximum shear capacity is mainly affected by the aggregate interlock mechanism, the dowel action of longitudinal reinforcement, the restraining action of stressed reinforcement crossing the crack interface and the possible presence of stirrups.
To appropriately describe the stress singularities at the crack tip and show the discontinuities of displacement and slope crossing the crack, previously used corner functions, as well as a new set of functions, are added to the well known admissible functions consisting of regular polynomials.
Meanwhile, the steel fibers crossing the crack came into play.
The recovery is initiated with sufficient number of fibers crossing the crack, which provide the required resistance across the surface of the crack.
This shear force must be balanced by the forces acting at the stirrups crossing the crack A v f v (z/s) cot θ.
This is attributed to the considerable contribution to shear resistance provided by both the stirrups crossing the crack and the strong dowel action provided by the MMFX longitudinal bars.
Hwang and Lee (2000) pointed out that the used concrete softening model tended to overestimate the softening effect in situations where behaviour was governed by yielding of all reinforcement crossing the crack direction.
In fiber-reinforced concrete (FRC), on the other hand, fibers crossing the crack interfaces significantly contribute to the load-carrying mechanism so that considerable tensile stress, being the sum of the tensile resistance provided by fibers and tension softening of the concrete matrix, respectively, can be achieved even with large crack widths (Lee et al. 2011).
In LGB with fibers perpendicular to the loading direction that do not cross the reduced area plane, the crack is inclined 45 degrees with respect to loading direction.
The results showed that the EMG-EBCs could resist the cracks from propagating through them due to the variation in elastic modulus along the depth beneath the surface, and thus could protect the composites from water-vapour corrosion, while the cracks could cross the single Sc2Si2O7 or BSAS coating to provide channels for oxidative gas diffusing and attacking the composites inside.
