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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

The UV-visible and IR properties of the Cu38 nanocluster depend to a great extent on the temperature. Density functional theory and nanothermodynamics can be combined to compute the geometrical optimization of isomers and their spectroscopic properties in an approximate manner. In this article, we investigate entropy-driven isomer distributions of Cu38 clusters and the effect of temperature on their UV-visible and IR spectra. An extensive, systematic global search is performed on the potential and free energy surfaces of Cu38 using a two-stage strategy to identify the lowest-energy structure and its low-energy neighbors. The effects of temperature on the UV and IR spectra are considered via Boltzmann probability. The computed UV-visible and IR spectrum of each isomer is multiplied by its corresponding Boltzmann weight at finite temperature. Then, they are summed together to produce a final temperature-dependent, Boltzmann-weighted UV-visible and IR spectrum. Additionally, Molecular Dynamics simulation of the Cu38 nanocluster was performed to gain insight into the system dynamics and make a three-dimensional movie of the system with atomistic resolution. Our results show the thermal populations at the absolute temperature of Cu38 cluster, and the disordered structure that dominates at high temperatures.