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, ...
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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.
Kian Asghari; Mehdi Vajdian
Volume 2, Issue 5 , August 2020, , Pages 55-68
Abstract
The use of fiber concrete can have a significant change in the quantity and quality of running structures or future plans of the country. Fiber concrete is actually a composite that increases the tensile strength by applying the reinforcing fiber inside the concrete mixture and is not easily break down ...
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The use of fiber concrete can have a significant change in the quantity and quality of running structures or future plans of the country. Fiber concrete is actually a composite that increases the tensile strength by applying the reinforcing fiber inside the concrete mixture and is not easily break down under the impact of impact loads. This composite combination has the proper integration and continuity and the possibility of using concrete as a possible material to produce wiggly-resistant surfaces. The use of macrosynthetic fibers increased the physical and chemical properties of concrete and reduced shrinkage of fresh and hardened concrete. Macrosynthetic fiber can be a suitable replacement for metal fiber and thermal rebars, so the use of this type of fiber has spread in recent years. Fiber concrete is currently widely used in various applications such as highways, foundations, military industries, protection walls, and other cases. In this research, the reason for the necessity of using kortta fiber, construction method, mechanical properties of fiber concrete samples according to the results of applications and research has been discussed.
Kian Asghari; Mehdi Vajdian
Volume 2, Issue 5 , August 2020, , Pages 69-86
Abstract
The destruction of concrete depends on the formation of cracks and cracks in the cracks. As the load increases, the cracks are connected together, forming the cracks. In order to overcome this problem as well as the creation of homogeneous conditions, in the last few decades, a series of thin strands ...
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The destruction of concrete depends on the formation of cracks and cracks in the cracks. As the load increases, the cracks are connected together, forming the cracks. In order to overcome this problem as well as the creation of homogeneous conditions, in the last few decades, a series of thin strands used in all the volume of concrete are used, which are called fibers. Fibers concrete is actually a composite that increases the tensile strength by applying the reinforcing fibers inside the concrete mixture. This composite combination has the proper integration and continuity and the possibility of using concrete as a possible material to produce wiggly - resistant surfaces. Fibers concrete is also highly capable of absorbing high energy and is not easily break down under the impact of impact loads. The historical witness of this technology is the great use of building buildings. As a matter of fact, fibers concrete is the advanced form of this technology, which is replaced by natural and synthetic fibres, replacement of straw, and cement replacement in the thatch. The fibers used in this study is of the type of polyolefin fiber and polyolefine. In this research, the reason for the necessity of using fibers, construction method, mechanical propeties and applications of fiber concrete and obtaining conversion coefficients of standard cubic samples of fiber concrete to standard cylindrical sample of fiber concrete according to the results of applications and research has been discussed.
