In reality, concrete structures are normally under various loadings, and results of different studies have shown that cracks in these structures and their materials, due to their nature as well as the loading type, do not develop along the crack plane (pure mode I); rather, they expand under mixed modes, making the crack growth studies under these modes a very important issue. In the crack growth phenomenon, the fracture toughness is a very effective parameter usually calculated by ENDB samples because they are easy to handle. In this study, several samples were made by changing the maximum aggregates size (dmax = 9.5, 12.5 & 19 mm) and the amount of hooked-end steel fibers (SF = 0.1, 0.3 & 0.5%), and tested under different loading modes (pure/mixed modes I and III) using the strain control jack device. According to the results, the lowest fracture toughness belonged to pure mode III, aggregates with dmax = 12.5 mm performed better in the self-compacting concrete reinforced with steel fiber, Also, the results show that the increasing trend of steel fibers does not have a positive effect on the fracture toughness performance.

Banks are the most important tool for preparing and supplying money in each country. In recent years, by institution of the new private banks and privatization of the governmental banks, banking competition has become very complex. This paper performs an empirical investigation to study the effects of different factors on return on assets and return on equities on 18 selected Iranian firms over the period 2002-2011. Using different regression models, the study studies the effects of total assets, debt ratio, etc. on return of assets (ROA) and return on equities (ROE) on selected eighteen Iranian banks as statistical community. The study considers total assets, ownership ratio, deposits to assets ratio, and loans to assets ratio as independent variables, and ROE and ROA as dependent variables. The results indicate that the private banks returns were better than governmental banks and the commercial banks’ returns were better than special banks. There is a reverse relationship between logarithm of total assets and ownership ratio with profitability based on return of assets.