The excessive production of worn tires remaining from the transportation system and the lack of proper procedures to recycle or reuse these materials have caused critical environmental issues. Due to the rubber’s toughness, this material could be implemented to increase concrete toughness, and by crushing the tires concrete aggregates can be replaced proportionally with rubber crumbs and large quantities of scrapped rubber. However, this substitution decreases the concrete strength. In this study, crushed rubber with sizes from 1 to 3 mm and 3 to 6 mm were replaced by 5%, 10%, and 15% sand; the combination of two additives of nano silica and metakaolin additives with optimum values was used to compensate the degradation of the strength and improve the workability of the concrete. Moreover, the compressive strength, tensile behavior, and modulus of elasticity were measured and compared. The results indicate that the optimum use of nano silica and metakaolin additives could compensate the negative effects of the rubber material implementation in the concrete mixture while improving the overall workability and flowability of the concrete mixture.
Steel plate shear walls (SPSWs) are among the most desirable load-bearing systems, which have been used wildly in various structures. Recently, designers have tended to SPSWs with only beam connections showing several problems. In the present research, several SPSWs with various types of connection conditions between infill plate and boundary elements, and various stiffness of boundary elements have been studied. The result illustrates that by having the full connection between infill plate and boundary elements, at least a 33% interconnected infill plate to columns could eliminate the significant loss of fundamental factors in SPSWs connected to beam only. Furthermore, increasing the stiffness of columns has more effect on the performance of SPSWs in comparison with beams.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.