دانلود رایگان مقاله انگلیسی بررسی کامپوزیت های فروسیمان برای تقویت ستون های بتنی - نشریه الزویر

abstract

The retrofitting and strengthening of concrete structures are becoming integral parts in construction and structural engineering practices owing to various situations that necessitate the enhancement in the capacity of structural members. Ferrocement composites are widely used for structural strengthening and rehabilitation in developing countries. The uniform distribution and high surface area-to-volume ratio of the reinforcement (wire mesh) of such composites improve the crack-arresting mechanism. Given these properties, ferrocement is an ideal material for repairing and strengthening old and deteriorated structures or structural members. Ferrocement composite has also been used as a jacketing material to strengthen axially loaded reinforced concrete (RC) members. Strengthening of concrete structures is an essential part of construction activities at present because these structures often suffer damage as a result of numerous environmental factors. The significance of these activities also increases with the insufficient capacity of structures that have been designed using old design codes. However, no codes have been developed for ferrocement composites as jacketing material to date. Moreover, a welldefined method for confining RC columns using ferrocement has not been established because of the lack of adequate research in this field. Thus, this study aggregates the current state of knowledge by reviewing available literature on the ferrocement jacketing of concrete columns and on ferrocement confinement effects. This study also determines research gaps in this field and suggests directions for future research to establish ferrocement composites as a feasible material for strengthening axially loaded concrete members.

7. Concluding

remarks The application of an effective and long-lasting strengthening technique can significantly increase the service life of concrete structures and thus reduce maintenance requirements. All the studies discussed in the current paper suggest that ferrocement jacketing effectively enhances the load-carrying and ductility capacities of RC columns. Although ferrocement is a labourintensive technology, it can be converted into labour-saving technology through modern mechanised pre-fabrication technology and the use of bolted connections to join precast units. Using high-performance mortar and high-strength reinforcing wire mesh can enhance the performance of ferrocement as strengthening material. The high in-plane shear strength and other improved engineering properties of ferrocement render it as an ideal, lowcost technology that is preferable over FRP or steel jacketing in strengthening RC columns, especially when increased shear strength is required. However, the theoretical and scientific background for the practical application of ferrocement must be enhanced through further extensive research. In addition, a practical guideline must be developed in relation to the use of this material to assist practicing engineers in structural strengthening.