In this paper, economic analysis on the effect of polyester fibers with high strength on the behavior of Hot Mix Asphalt (HMA) is performed. The results indicate that strength is increased by adding fiber to asphalt. Also, unit weight of asphalt mixture was used as a variable parameter in the analyses. The results show that in some certain percentages of fiber, in addition to the enhancement in mechanical properties of HMA mixture the economic benefit value becomes more than the cost and therefore adding polyester fibers with high stability is suggested for the mixture of modified asphalt concrete. Finally, it can be concluded that adding fibers in values of 0.2% to 0.5% has the best result on the asphalt mixture, which because of high resistance and economic aspects makes it more efficient to be used in the highways of warm regions containing traffic.

In this study, the behavior of two buildings designed with steel structures Buckling Restrained Braced (BRB) and conventional bending frame was studied to analyze their strengths against progressive collapse. The structures were designed and analyzed in accordance with Iranian regulation No. 2800 for the design of buildings. Using nonlinear static pushover analysis, the performance of the structure after removal of the center and the corner columns were investigated and it was demonstrated that removing the corner column provides more critical conditions for the investigated buildings. Furthermore, the use of BRB elements provides better performance for the analyzed buildings due to the ability of BRB in absorbing and dissipating more energy induced from the external loading sources like the earthquake.