<p dir="ltr">Post-tensioned concrete is a popular structural system in modern bridge design, allowing for longer bridge spans and the construction of curved, spliced, and segmental girders. When designed and constructed properly, post-tensioned concrete can offer improved durability over reinforced concrete as it is more resistant to cracking. However, corrosion of prestressing strands can compromise the integrity of post-tensioned construction. Grouting has been the primary method of providing corrosion protection to the prestressing strands. However, grouting of tendons presents numerous limitations and results in multiple problems in practice. As a result, there has been increased interest in the use of unbonded tendons. Corrosion protection can still be achieved in unbonded tendons through the use of flexible fillers such as grease and microcrystalline wax. Limited research has been conducted on unbonded tendons, and no known research exists regarding the behavior of unbonded tendons subject to torsion. The objective of this research was to investigate the torsional behavior and strength of unbonded post-tensioned bridge girders. The scope of work included testing six specimens to investigate the difference in behavior between bonded and unbonded tendons as well as the influence of internal versus external ducts. The influence of transverse reinforcement was also considered.</p>

El presente trabajo, consiste en la implementación de estos disipadores fluido-viscosos en una edificación con predominación de muros estructurales de 5 niveles que presenta un comportamiento torsional. El diseño de estos disipadores, parten con el objetivo de diseño de daño moderado y bajo un sismo de 475 años de periodo de retorno, es decir que la deriva objetivo necesario para el diseño es 0.58%. Se analiza bajo la colocación en diagonal para amortiguadores lineales y no lineales. La colocación se hace de manera uniforme, y de manera que compense el movimiento torsional. Se colocaron un total de 40 disipadores en todo el edificio. Entre los principales resultados, la fuerza fuerzas en los disipadores fueron en un orden de 213 ton-f y comportamiento torsional debido a zonas frágiles de la estructura fueran reducidas en 80%. La implementación de los disipadores fluido-viscosos permiten reducir la deriva en 60% y todas las derivas se mantienen por debajo de 0.58%, en teoría. En un futuro, en el Perú, será necesario implementar una normativa para el diseño y el aporte de amortiguamiento en el edificio. / The present work consists of the implementation of these fluid-viscous dissipators in a building with a predominance of structural walls, of 5 levels that presents a torsional behavior, as well as fails to comply with the permissible drift limit established by Norma Técnica E.030. The design of these dissipators starts with the design objective of moderate damage and under an earthquake of 475 years of return period, whose corresponding objective drift assumes a value of 0.58%. It is discussed under diagonal placement for linear and nonlinear dampers. The placement is done uniformly, and in a way that compensates for torsional movement. A total of 40 heatsinks were placed throughout the building, 8 per floor. Among the main results, the forces in the dissipators were in the order of 200 ton-f and torsional behavior due to flexible areas of the structure were reduced by 80%. The implementation of fluid-viscous heatsinks allows the drift to be reduced by 60%, and all drifts are kept below 0.58%, that is, both linear and non-linear devices meet the target drift, even though the latter have a higher drift, given their lower C, therefore, lower force, less drift control, even so, they are efficient, both structurally and economically, given their lower strength. In the future, in Peru, it will be necessary to implement a regulation for the design and the cushioning contribution in the building. / Trabajo de investigación