RESUMEN
The objective of this study is to evaluate the effect of Fiber-Reinforced Polymer (FRP) coatings on the mechanical properties of concrete structures, especially those used in the production of power distribution poles. These coatings consist of carbon, glass, hybrid, and aramid fibers embedded within a polyurethane matrix. Aramid fabrics from discarded ballistic garments were used to produce FRP. To achieve this, flexural, Charpy impact, and adhesion tests were conducted on the FRP-reinforced concrete. Additionally, Scanning Electron Microscopy (SEM) analyses were performed on the fracture regions of materials tested for impact resistance. The results indicated that all fabrics utilized in the study enhanced the mechanical properties of the concrete specimens in terms of flexural strength and toughness. The observed differences between the fiber types can be attributed to the unique chemical structures of each fiber and their respective interactions with the PU matrix at the interface. These findings suggest that such coatings can significantly improve the mechanical performance of concrete structures.
RESUMEN
This work presents a methodology for polycyclic aromatic hydrocarbons (PAHs) trapping from vehicular emissions using an in-tube extraction device (IT-FEx). Trapping selectivity studies were conducted, evaluating the interaction profile between the aromatic compounds and the polymeric phase (composed of polydimethylsiloxane and internal to the IT-FEx devices), as in an aqueous equilibrium system (25 min of sampling), and as in gaseous dynamic phase (30 s of sampling), regarding a qualitative evaluation. The adsorption profiles were similar, with greater affinity for medium-sized PAHs (four aromatic rings) than for the smaller (one to three rings) and larger (five to six rings). The device was attached to a vehicle emission sampler to evaluate the qualitative emission of diesel-powered vehicles. Certain PAHs, such as phenanthrene, fluoranthene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, and benzo[k]fluoranthene, were effectively trapped by the IT-FEx device and detected by the GC-BID analysis. Finally, it was possible to develop a process that combined the steps of sample preparation and instrumental analysis, using the IT-FEx device and applying it to the gaseous matrix in the dynamic phase; until then, little was elucidated regarding the use of this apparatus. This sampling device, combined with analysis by gas chromatography with a barrier ionization discharge detector (GC-BID), is a powerful tool for identifying many compounds from vehicular emissions and does not require solvents in sample preparation.