Ramona Petrov - Academia.edu (original) (raw)
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Papers by Ramona Petrov
Zbornik radova Građevinskog fakulteta, 2021
The subject of this paper is the basis of structural design according to the proposal EN 1998-1: ... more The subject of this paper is the basis of structural design according to the proposal EN 1998-1: 2004, in seismically active areas. The static linear-elastic method, the method of equivalent lateral forces and the nonlinear ("pushover") method for estimating the nonlinear behavior of reinforced concrete load-bearing structures during seismic actions are presented. The paper presents the requirements for the adoption of dimensions and reinforcement of sections in accordance with the regulations of Eurocode 8, which should, in addition to the required loadbearing capacity, meet the requirements of local ductility, which prevents the formation of a plastic mechanism in the form of a flexible floor. By the method of equivalent lateral forces, the seismic action is represented over the acceleration spectrum. Linear elastic analysis of the structure was done using the program "Tower", where the cross sections were adopted and sizing was done strictly taking into account the recommendations from EC 8. In the Tower, two-dimensional elements were used in the analysis of the structure. A nonlinear analysis of the frame with the same adopted dimensions, reinforcement and authoritative load combination was done in the "Abaqus" program, the result of which is the push curve. For modeling columns and
This paper provides some new views of the familiar problems of measurement and testing of creep a... more This paper provides some new views of the familiar problems of measurement and testing of creep and shrinkage of concrete rheological time deformation. Concrete creep is not a theoretical, but a structural problem and solutions must be sought exclusively by experimental tests and measurements. On the basis of such measurements, monitoring and observing the structural changes, it is possible to make theoretical assumptions. What is well known is that the creep directly depends on the condition and magnitude of the stresses to which the concrete cross section is exposed. Those sections of concrete that are only partially used, in terms of stress, are not as sensitive to creep as sections that are loaded to the point of proportionality. A particular problem and the enormous increase in the creep of concrete would occur if sections were loaded above the points of proportionality and elasticity. The creep of concrete over time on real structures in use, in most cases, both in old and new structures, increases unpredictably in the first years. One can ask a question and doubt the magnitude of the actual stress states to which the concrete structures are exposed. Our measurements for determining an ultimate strength of concrete on cubes, prisms and cylinders indicate such doubt. During the conducted tests of creep and shrinkage of concrete, which were done in doctoral studies in 2020 at the Faculty of Civil Engineering in Subotica, which are still ongoing, we present only one segment related to the topic of stress to which sections in concrete structures are exposed.
Zbornik radova Građevinskog fakulteta, 2021
The subject of this paper is the basis of structural design according to the proposal EN 1998-1: ... more The subject of this paper is the basis of structural design according to the proposal EN 1998-1: 2004, in seismically active areas. The static linear-elastic method, the method of equivalent lateral forces and the nonlinear ("pushover") method for estimating the nonlinear behavior of reinforced concrete load-bearing structures during seismic actions are presented. The paper presents the requirements for the adoption of dimensions and reinforcement of sections in accordance with the regulations of Eurocode 8, which should, in addition to the required loadbearing capacity, meet the requirements of local ductility, which prevents the formation of a plastic mechanism in the form of a flexible floor. By the method of equivalent lateral forces, the seismic action is represented over the acceleration spectrum. Linear elastic analysis of the structure was done using the program "Tower", where the cross sections were adopted and sizing was done strictly taking into account the recommendations from EC 8. In the Tower, two-dimensional elements were used in the analysis of the structure. A nonlinear analysis of the frame with the same adopted dimensions, reinforcement and authoritative load combination was done in the "Abaqus" program, the result of which is the push curve. For modeling columns and
This paper provides some new views of the familiar problems of measurement and testing of creep a... more This paper provides some new views of the familiar problems of measurement and testing of creep and shrinkage of concrete rheological time deformation. Concrete creep is not a theoretical, but a structural problem and solutions must be sought exclusively by experimental tests and measurements. On the basis of such measurements, monitoring and observing the structural changes, it is possible to make theoretical assumptions. What is well known is that the creep directly depends on the condition and magnitude of the stresses to which the concrete cross section is exposed. Those sections of concrete that are only partially used, in terms of stress, are not as sensitive to creep as sections that are loaded to the point of proportionality. A particular problem and the enormous increase in the creep of concrete would occur if sections were loaded above the points of proportionality and elasticity. The creep of concrete over time on real structures in use, in most cases, both in old and new structures, increases unpredictably in the first years. One can ask a question and doubt the magnitude of the actual stress states to which the concrete structures are exposed. Our measurements for determining an ultimate strength of concrete on cubes, prisms and cylinders indicate such doubt. During the conducted tests of creep and shrinkage of concrete, which were done in doctoral studies in 2020 at the Faculty of Civil Engineering in Subotica, which are still ongoing, we present only one segment related to the topic of stress to which sections in concrete structures are exposed.