Mohammad Javad Gudarzi; Mahdi Vajdian
Abstract
Concrete strength as an important parameter can play an important role in the behavior and performance of the structure. Therefore, the use of high-strength concrete can improve the performance of the structure, of course, this is an assumption that must be checked by testing and modeling. In this article, ...
Read More
Concrete strength as an important parameter can play an important role in the behavior and performance of the structure. Therefore, the use of high-strength concrete can improve the performance of the structure, of course, this is an assumption that must be checked by testing and modeling. In this article, the effect of compressive strength on the behavior of concrete structures has been investigated. In this research, three frames with 5, 10, and 15 floors, which have a system, a medium-type bending frame according to the standard (2800) and the ninth topic of the national design regulations, finally, nonlinear dynamic analysis is applied to the model. The analysis and design of frames was done with the help of ETABS software. In this study, the compressive stress parameter of concrete is considered as the main variable, and two types of light concrete with a strength of 25 MPa and 55 MPa will be considered. After obtaining the sections of the desired structure, it is coded in OpenSees software. 10 records have been used to obtain fragility curves. By examining the results related to heavy and light concrete, it can be seen that in all three studied structures (five, ten and fifteen stories), the structure with heavy concrete has less drift in the same PGA as the structure with light concrete, with an averaging of the observation results. It has been found that the structure with heavy concrete has less relative displacement in the range of 15 to 24% than the structure with light concrete.
Kourosh Mehdizadeh; Seyede Vahide Hashemi; Abbasali Sadeghi; Farshid Movafegh Ghadirli
Volume 2, Issue 2 , May 2020, , Pages 56-76
Abstract
Today, the use of high strength concrete in large projects around the world has become very common. It is almost impossible to build the world's largest and tallest structures without using high strength concrete technology. On the other hand, due to the wide range of concrete structures in our country, ...
Read More
Today, the use of high strength concrete in large projects around the world has become very common. It is almost impossible to build the world's largest and tallest structures without using high strength concrete technology. On the other hand, due to the wide range of concrete structures in our country, the regulations for the design of concrete structures do not mention the effects of concrete strength on the dynamic performance of the structure; Therefore, the aim of this study is to investigate the seismic performance of concrete structure with common and high strength concrete by using nonlinear dynamic time history analysis, so that the effect of parameters such as roof displacement, base shear, and axial force of the columns is compared. Therefore, at first, 2-storey concrete moment frame structure with intermediate ductility was designed in three-dimensional mode, according to the available regulations, then the real details were modeled in ABAQUS software. In order to perform nonlinear analysis, nonlinear model is used for structural elements and seismic analysis of the system is performed using three near-fault pairs of accelograms. The results show that increasing the strength of the concrete increasing the base shear as well as the stiffness of the stories, and the axial force values of the columns is almost ineffective.
