Browsing by Author "Chalangaran, Navid"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Experimental Investigation of Sound Transmission Loss in Concrete Containing Recycled Rubber Crumbs
    Chalangaran, Navid; Farzampour, Alireza; Paslar, Nima; Fatemi, Hadi (Technopress, 2021-05-15)
    This study represents procedures and material to improve sound transmission loss through concrete without having any significant effects on mechanical properties. To prevent noise pollution damaging effects, and for reducing the transmission of the noises from streets to residential buildings, sound absorbing materials could be effectively produced. For this purpose, a number of several mixture designs have been investigated in this study to reduce the sound transmission through concrete, including control sample and three mixtures with recycled rubber with sizes of from 1mm up to 3 mm to limit the sound transmission. The rubber is used as a replacement of 5, 10, and 15 percent of sand aggregates. First, 7, 14 and 28-day strengths of the concrete have been measured. Subsequently, the sound transmission losses through the samples have been measured at the range of 63 Hz up to 6300 Hz by using impedance tube and the transfer function. The results show specimens containing 15% fine-grained crumbs, the loss of sound transmission were up to 190%, and for samples with 15% coarse-grained rubber, the loss of sound transmission were up to 228%, respectively. It is shown that concrete with recycled rubber crumbs could effectively improve environmental noise absorption.
  • Thumbnail Image
    Investigations on The Structural Behavior of Steel Plate Shear Walls with Partially Interconnected Infill Plates
    Paslar, Nima; Farzampour, Alireza; Chalangaran, Navid; Mansouri, Iman; Wan Hu, Jong (2023-07-08)
    Steel plate shear walls are considered an effective lateral load-resisting system widely used in space-constrained high-rise buildings. Steel plate shear walls could improve several structural parameters such as strength, energy absorption, and stiffness. Recently, there is a tendency to have limited connection between the infill plate and boundary elements to prevent significant direct demands on columns, and possible brittle modes of behavior leading to the economical design of various structural elements. However, previous studies showed that the absence of the interconnection between infill plate and columns in steel plate shear walls with beam-connected systems could reduce the performance of the system significantly. In the present study, procedures to improve the performance of the steel plate shear walls with limited infill plate interconnections with the boundary elements are provided. Subsequently, computational steel plate shear wall models, with and without boundary infill plate stiffeners and different widths of the infill plate have been investigated after fully validating the computational modeling methodology to find efficient procedures for eliminating the lack of interconnections. The results show that utilizing boundary stiffeners increased ultimate strength, energy dissipation and stiffness by 15%, 20%, and 24% on average. Although boundary stiffeners cannot fully control the out-of-plane displacements of the infill plate, they would be useful in improving the formation of tension field actions. Furthermore, it is shown that the width of the infill plate and boundary stiffeners are the key factors in the performance of the system.
  • Thumbnail Image
    Nano Silica and Metakaolin Effects on the Behavior of Concrete Containing Rubber Crumbs
    Chalangaran, Navid; Farzampour, Alireza; Paslar, Nima (MDPI, 2020-11-08)
    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.