Corrosion of rebars in recycled glass concrete under tropical marine environment

Abstract

This study demonstrates the potential use of recycled powder glass as cement replacement to prepare durable concrete and avoid infrastructure corrosion in tropical marine environments using limestone as fine and coarse aggregates. Samples for corrosion measurements were prepared with #3 (~9.5 mm) bars and without reinforcement for carbonation, chloride penetration, and mechanical strength tests. Powder glass was used as partial cement replacement by 0 %, 5 %, 10 %, and 15 % (weight percent). Over two years, the corrosion behavior of rebars was recorded through corrosion potential measurements and linear polarization resistance. In addition, carbonation depth and chloride penetration were analyzed from samples that were not reinforced. Results showed that replacing cement with glass does not change the mechanical strength at 28 days, but after 90 days of curing showed an increment as a function of time and recycled glass powder amount. The chloride penetration and the carbonation front are reduced substantially. Consequently, a moderate corrosion level was observed when the corrosion onset was established. Excellent corrosion protection was identified for a 0.70 water to cement ratio and 5 % cement replacement. Keywords: Carbonation concrete / chlorides rebars / corrosion / glass waste recycling / tropical marine environment Schlüsselwörter: Karbonatisierter Beton / Chloride / Betonstahl / Korrosion / recyceltes Glas / tropisch-marine Umgebungsbedingungen