No abstract

Unlike the conducted studies in the field of reinforcing the asphaltic mixture, this research has used the multi-criteria decision-making method to determine the optimal percentage of the asphalt mix, which was reinforced with rubber powder and carbon fibers. After adding different percentages of two kinds of additives, i.e. rubber powder and carbon fibers conjointly, conducting Marshall Tests, analyzing the data and plotting the needed diagrams, it was observed that adding these two additives leads to a change in the results of Marshall Tests. Analyzing the diagrams, the optimal percentages for combining the rubber powder with carbon fibers were obtained, 15% and 0.5%, respectively having the best effect on the asphalt mix. Subsequently, the extra cost caused by adding the additives to the asphalt was evaluated by conducting an economic analysis. Then, six Mar-shall Parameters were used as six indices in the concordance analysis method, which is a multi-criterion decision-making method. Ultimately, the superior alternatives were proposed according to the results of the ranking. Ac-cording to the results, the suggested alternatives differed from the estimated alternative and the concordance analysis method proposed better alternatives.

In this article by adding different percentages of carbon fiber with high strength and doing the necessary Marshall tests, it was observed that the Marshall Resistance and its Flow increased. Due to their armed properties, the carbon fibers have a positive effect on Marshall Resistance. According to the results, in-creasing the percentage of fibers, reduces the resistance, so that the resistance of the sample containing 1.5% of carbon fiber is almost 32% more than the resistance of the sample without fiber. According to the results, the increased resistance compared to the previous researches and other fibers stems from the kind of fiber used in it and its high resistance. After increasing the fiber percentage to 3, a 12% decrease in the resistance was seen. On the other hand, by changing the percentage of the fibers added to the aggregates, the Flow will change, so that the sample containing 3% of fiber is almost 189% more Flow than the base sample. The economic analysis was used for a three-lane road. The results showed that economically speaking, due to their high price, these types of fibers are recommended to be used in restricted and optimal areas.

No abstract

No abstract

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.

The main purpose of Hot Mix Asphalt (HMA) is to choose the most suitable and the most affordable mix of bitumen and aggregates, so that it can maintain the technical properties of the asphalt concrete in certain amounts. Different methods have been suggested for mixing the Hot Mix Asphalt (HMA) including the Marshall method, the modified Marshall method, Hveem method, and the Superpave mixing method. Concurrently, the project of mixing Hot Mix Asphalt (HMA) in Iran is done based on the Marshall method and the modified Marshall method. Regarding the weaknesses of the asphalt mixes in different situations, the engineers try to modify and improve the properties of the asphalt mix by use of different additives. On the other hand, the additional expenses of various additives to the asphalt mix for building one kilometer of the road is a negative parameter. However, by use of the additives, the technical properties of the asphalt mix improve. Therefore, to decide on a proper choice out of the alternatives would be a difficult task. This paper, tries to provide an appropriate method for evaluating and choosing the best alternative by taking into consideration all the technical criteria. In this article, we first evaluate the score and the weight of each alternative in each criterion. Then, the weight of each criterion is evaluated using the best-worst method, and eventually, taking all aspects into consideration, the rankings of different alternatives will be determined based on two situations: certain situation and uncertain situation.

No abstract