Chloride-induced corrosion in reinforced concrete and fiber reinforced concrete elements under tensile service loads

Abstract

Corrosion of rebars is one of the main issues affecting the service life of Reinforced Concrete (RC) structures. It is well-known that the use of fibers enhances the mechanical behavior of RC structures at both Serviceability Limit States (SLS) and Ultimate Limit States (ULS). In the former, fibers mainly influence the cracking pattern, leading to narrower and more closely spaced cracks. The crack width is a key parameter for controlling the durability of RC structures along with concrete quality and the thickness of the concrete cover. Even though many research studies have been carried out on this topic, the behavior of RC elements, with and without fibers, in both cracked stage and aggressive environments is still not well understood. This article describes an innovative test procedure specifically developed to evaluate the chloride-induced corrosion in RC elements with and without fibers in service condition (under tensile stress and in the cracked stage). Prismatic specimens 90 × 90 × 830 mm with Ø12 rebar (called hereafter tension ties) were subjected for 280 days both to a tensile load and to wet-dry cycles in a water solution containing 5% of NaCl. Experimental results indicate that this test procedure was suitable to assess the chloride-induced corrosion in tensile elements in the cracked stage. Furthermore, a positive influence of fibers was observed, while no relationship between crack width and pitting depth was found.