An ordinary portland cement and two portland limestone cements [15 and 35% weight-to-weight ratio (w/w) limestone content] were used for concrete and reinforced mortar specimens preparation. The specimens were exposed to two corrosive solutions (chloride sulfate and chloride) at 5°C. Total (acid-soluble) and free (water-soluble) chloride contents, and apparent chloride diffusion coefficients, were determined in concrete specimens. Reinforcement corrosion half-potential and current density, mass loss of steel rebars, and carbonation depth were measured in mortar specimens. Limestone cements showed very good behavior, although the environments were very corrosive. Total and free chloride ions concentration increased with exposure time and limestone content. Limestone cements showed less capability of binding chlorides than pure portland cement. The cement with low limestone content was the most effective in preventing reinforcement corrosion during mortar exposure to the combined chloride-sulfate solution, although it allowed the most intensive corrosion in the case of the chloride-bearing solution. The presence of sulfates led to higher chloride ion concentrations, less chloride binding and, generally, higher values of chloride diffusion coefficient, and also promoted reinforcement corrosion to a greater extent. Low temperature conditions retained a relatively low corrosion rate.

An experimental investigation was carried out to study the effect of thermoplastics’ addition to reinforcement corrosion and the durability of concrete. A long-term study is necessary for the final decision on the possibility of the utilization of materials, and this study is contributing to this direction. Two types of thermoplastics were used, high-density polyethylene and polypropylene. The percentage of replacement of conventional aggregates was 0% and 12% by volume. After being demolded and cured for 7 days, the specimens were immersed in 3.5 wt% NaCl solution for 240 days. Afterwards, they were left in laboratory ambient air up to 11 years. Carbonation depth and the volume of permeable voids were determined. Optical microscopy, stereoscopy, and electrochemical impedance spectroscopy measurements were performed. Results showed that replacing conventional limestone aggregates with the particular two thermoplastics does not have a negative impact on rebars’ corrosion behavior. Optical microscopy and stereoscopy of rebars’ surface revealed that the corrosion process has initiated and carbonation is observed in all mixes, but corrosion rates are negligible for all the mixes studied.

Poly(vinyl butyral) (PVB) is widely used as an interlayer in laminated safety glass in automotive and construction applications. The increasing quantities of PVB arising from end-of-life laminated glass represent a waste stream with significant potential for recycling. This study investigates the durability of high-quality retrieved PVB (re-PVB) separated from laminated glass wastes and evaluates the effect of restabilization against UV aging. Neat unplasticized PVB (u-PVB) and re-PVB were subjected to artificial UV weathering (ISO 4892-3) for up to 1500 h and then characterized in terms of chemical structure, yellowness, melt flow behavior and molecular weight. The results showed that u-PVB exhibited pronounced photooxidative degradation, while re-PVB remained comparatively stable. UV–Vis spectroscopy revealed the presence of residual UV absorbers in re-PVB, indicating that the components of the initial stabilization system might remain functional after the end of its life. Unexpectedly, the restabilization of re-PVB with phenolic antioxidants (AOs) reduced its photooxidative stability, despite their established effectiveness against thermo-mechanical degradation in melt reprocessing. A possible antagonistic effect was suggested between the newly introduced AOs and the residual stabilization system. These findings highlight that re-PVB is a valuable waste, and restabilization should be carefully considered when designing its second service life.