Durability of Recycled Steel Fiber Reinforced Concrete in Chloride Environment

Abstract

For structural elements exposed to chloride environments, an important aspect of Recycled Steel Fiber Reinforced Concrete (RSFRC) durability is the corrosion resistance. In the present work, an experimental program was carried out to evaluate the long-term effects of chloride attack on the post-cracking behavior of RSFRC by performing splitting tensile tests and round panel tests. Two RSFRC mixtures defined based on the packing density optimization were produced with a fiber content of 0.8% and 1% per volume of concrete. The influence of different periods of chloride immersion was investigated, as well as the influence of fiber dispersion at crack surfaces of the specimens. Additionally, a simplified prediction of the long-term chloride penetration depth into uncracked RSFRC under immersion aggressive chloride exposure conditions was estimated. The RSFRC revealed high susceptibility to surface corrosion under the chloride exposure conditions adopted. However, the post-cracking resistance of RSFRC was not significant affected. The addition of RSF had a negligible effect in the diffusion of chloride ions into concrete, and the critical chloride content was higher than that found in conventional reinforced concrete structures.

Experimental Investigation on the Freeze–Thaw Resistance of Steel Fibers Reinforced Rubber Concrete

“…Steel fiber is one of the most popularly used fibers to enhance the mechanical strength of concrete [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43]. Nguyen et al indicated that the effects of rubber aggregates and fiber reinforcement could result in better cracking resistance for cement mortar [28].…”

Meso-Scale Formulation of a Cracked-Hinge Model for Hybrid Fiber-Reinforced Cement Composites

“…As for the contribution of fibers, it is controlled by the crack opening displacement w k expressed in Equation (11). Moreover, the present formulation assumes a complete reorientation of fibers crossing the cracked section: regardless of their initial inclination (described by the angles α x,k and α z,k ) they are supposed to exert axial stresses σ f,k depending on both the lateral bond stress τ mobilized throughout the lateral area and the possible contribution F of the hooked end (see Section 3.3).…”

“…Fiber-reinforced cementitious composites (FRCCs) are a class of concrete-like material developed in the last two decades with the aim of mitigating the inherent fragility of concrete in tension [1]. Several types of fiber are currently adopted as spread reinforcement in FRCCs, which range from the very common steel fibers [2][3][4][5], to the ones either made of plastics [6] or, more recently, obtained from plants [7,8], or produced by recycling waste tires [9][10][11]. Moreover, FRCCs can also be produced by blending different types of fibers to produce a class of composites often referred to as hybrid-FRCCs (Hy-FRCCs) with the aim to mobilize a synergistic action from each fiber [12][13][14][15][16][17].…”

Influence of the Chloride Attack on the Post-Cracking Behavior of Recycled Steel Fiber Reinforced Concrete

“…In recent years, several investigations have explored the potential of end-of-life tires by-products in the construction industry, such as the use of recycled steel fibers (RSFs) in the reinforcement of cement-based materials [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ], namely, in fiber reinforced concrete (FRC). FRC is being used in slabs and shells, such as the case of flooring and tunneling since the support redundancy of this type of structure favors the occurrence of a high level of stress redistribution during crack propagation, which increases their ultimate load regarding their cracking load [ 8 , 9 ].…”