## 1 Introduction  
The idea of reinforcing brittle matrices with discrete fibers is somehow intuitive and can even be found in wildlife, whose most emblematic example may be the nest of the Hornero (_Furnarius rufus_), the engineer bird. Considering mankind, the concept dates from nearly 45 centuries ago--when straw fibers were mixed with mud and then molded in rectangular prisms to be sun-dried and produce improved construction blocks--and has been evolving ever since. Steel fiber-reinforced concrete (SFRC)--a mixture of a concrete matrix with randomly oriented short steel fibers--is probably the most popular application of the concept. This composite has been traditionally applied to flooring along with tunnel and mine linings [1]. Then, its utilization was extended to the compressive layer of bridge decks, precast concrete industry, nuclear waste vessels, water retention, and seismic-resistant structures, amongst others. Recently, SFRC has started to be utilized as complementary reinforcement in prestressed [2] and reinforced concrete [3, 4]. All these applications are grounded in the acknowledged ability of SFRC to control cracking development inside the matrix [5], thus improving the flexural and tensile behavior [6, 7, 8]. The widespread use of SFRC is naturally supported by extensive research that started in the 1960s [9]. The main outcomes of the research carried out so far are codes and recommendations for the testing and design of the mechanical behavior of SFRC [10, 11, 12, 13]. Durability is an important dimension of the performance of any material. According to [PERSON] and [PERSON] [14], this subject, concerning SFRC, has been studied since the early 1990s. The existing studies are mostly devoted to the influence of fibers on transport properties [15] and, concerning fiber corrosion, in cracked SFRC. [PERSON] et al. [16] reported an increase in transport properties with steel fiber content, while [PERSON] and [PERSON] [17] observed lower resistance to acid attack with the increase in fiber content. [PERSON] and [PERSON] [18] found no significant modifications in transport propertieswith fiber addition, which is in accordance with the results of the experiments carried out by [PERSON] et al., either in ordinary [19] or self-compacting concrete [20], concerning chlorides. The results of [PERSON] et al. [21] also show no significant influence of steel fibers on chloride diffusion, up to a volume content of 2%. The first major publication addressing fiber corrosion effects on the mechanical performance of SFRC is from 1987 and reports improvements in the mechanical properties of cracked SFRC subject to corrosion. This has been ratified in later studies. For instance, [PERSON] and [PERSON] [14] observed a strength increase for cracked SFRC subject to corrosion, despite the (light) corrosion of the fibers. The improvement is attributed to the rise in friction between fibers and matrix promoted by the accumulated corrosion products. [PERSON] et al. [22] concluded in their literature review that corrosion of fibers, bridging cracks with openings of less than 0.2 mm, is limited to staining and does not cause further cracking or spalling. Several studies [22; 23; 24] revealed that fiber corrosion is limited to a certain depth, ranging from 0.1 to 5 mm, but can reach as deep as 30 mm if the concrete is mixed with seawater [25]. However, this limited corrosion causes no detachment or spalling [24], but aesthetic damage. Moreover, improvements in the mechanical performance of uncracked SFRC were also reported [22; 26; 27]. Contradicting the idea of [PERSON] et al. [22] that, in SFRC, corrosion damage, either aesthetical or mechanical, tends to stabilize in time, loss of mechanical performance for longer test periods is disclosed in [19; 26; 28]. Further, for exposure to simulated marine showers, loss of performance at a constant rate is visible in the charts of [PERSON] and [PERSON] [27].