scholarly journals Simplified Time-Dependent Column Shortening Analysis in Special Reinforced Concrete Moment Frames

2017 ◽  
Vol 62 (1) ◽  
pp. 232-249 ◽  
Author(s):  
Mohammad Jalilzadeh Afshari ◽  
Ali Kheyroddin ◽  
Majid Gholhaki
Keyword(s):  
Reinforced Concrete ◽  
Frame Structures ◽  
Moment Frames ◽  
Moment Frame ◽  
High Rise ◽  
Geometrical Characteristics ◽  
Time Changes ◽  
The Moment ◽  
Long Term Behavior

Necessity for adaption of high-rise reinforced concrete structures’ design and practical steps of implementation through nonlinear staged analysis by consideration of long-term behavior of concrete have always been strongly recommended by researchers in recent years. Cumulative column shortening in conventional analyses is the most important consequence of neglecting the above issues. In this article, numerous modeling and extensive nonlinear staged analyses are carried out on structures with different geometrical characteristics and extremely simple empirical equations to estimate column shortening caused by creep, shrinkage and time changes of modulus of elasticity are provided in such a way that these relations can be independent of conventional parameters of ACI209R-92 regulations used in prediction of mentioned axial strains. Results obtained from validation of the proposed equations show high compliance of all proposed equations for up to 30 floors and also show accuracy of proposed shrinkage equation for the moment frame structures higher than the studied range.

A Predicting Method for Long-Term Behavior of Reinforced Concrete Moment Frames

2019 ◽  
Vol 116 (6) ◽  
Author(s):  
Mohammad Jalilzadeh Afshari ◽  
Ali Kheyroddin
Keyword(s):  
Reinforced Concrete ◽  
Moment Frames ◽  
Long Term Behavior

scholarly journals Improving resilience of moment frames using steel pipe dampers

2018 ◽  
Vol 195 ◽  
pp. 02014
Author(s):  
Junaedi Utomo ◽  
Antonius
Keyword(s):  
Numerical Study ◽  
Steel Pipe ◽  
Frame Structures ◽  
Earthquake Risk ◽  
Moment Frames ◽  
Moment Frame ◽  
Story Drift ◽  
Moment Resisting ◽  
Lateral Displacements ◽  
The Moment

Earthquake resiliency of moment resisting frames, either new or existing ones, are important for maintaining community functionality. Improving earthquake resiliency needs a strong initiative in reducing earthquake risk. Steel pipe dampers can be used to increase earthquake resiliency. Steel pipe dampers, when installed at strategic locations in the moment frame structures, dissipate most of the earthquake energy in structures through inelastic deformation so that other components of the structure are protected. Steel pipe dampers control vibration in moment frame structures and are a disposable component in structures so that the damaged dampers can be replaced easily. Steel pipe dampers are cheap and require low workmanship, therefore the recovery time after disasters is short and the cost of recovery is low. Utilizing steel pipe dampers in passive energy dissipation systems help maintain community functionality during and after disasters. Lateral displacements were quantified and used as performance indicators. Significant drift and inter story drift reduction were achieved during a numerical study. All structural components, except the steel pipe dampers, remain elastic, indicating the effectiveness of the dampers in reducing the losses due to earthquakes.

Long-Term Deformations of Strengthened Reinforced Concrete Linear Elements

2016 ◽  
Vol 691 ◽  
pp. 51-60 ◽  
Author(s):  
Martin Krizma ◽  
Lubomir Bolha
Keyword(s):  
Reinforced Concrete ◽  
Long Term Results ◽  
Short Term ◽  
Limit States ◽  
Linear Elements ◽  
Repeated Load ◽  
The Moment ◽  
Concrete Elements ◽  
Fiber Fabric

The issue of strengthening the damaged linear reinforced concrete elements have been engaged since 2008. We focused on the analysis of resistance and the characteristics of limit states of serviceability in the damaged and subsequently strengthened elements at a short-term loading. In the introduction phase, the strengthening of the elements was carried out with the following procedures – installation of an overlayer on the coupling board or a combination of the board and use of glass – fiber fabric (GFRP). The strengthening was also affected by the type of contact (reinforced/non-reinforced) – the deformed element/coupling board and its effect on resistance, type of deformation and serviceability. In the non-reinforced contact, we applied some of the types of adjustments to the surface of the strengthened element. At the moment, we are dealing with the effects of time and repeated load on the strengthened elements. The results correspond to the reinforced contact. The values are compared with the short-term results of the strengthened beams and with the long-term results of the beams prepared for strengthening.

scholarly journals Long-term behavior of cracked fiber reinforced concrete under service conditions

2019 ◽  
Vol 196 ◽  
pp. 649-658 ◽  
Author(s):  
D.H. Monetti ◽  
A. Llano-Torre ◽  
M.C. Torrijos ◽  
G. Giaccio ◽  
R. Zerbino ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Service Conditions ◽  
Long Term Behavior

scholarly journals Equivalent Frame Model with a Decaying Nonlinear Moment-Curvature of Steel-Reinforced Concrete Joints

2019 ◽  
Vol 9 (24) ◽  
pp. 5533 ◽  
Author(s):  
Isaac Montava ◽  
Ramón Irles ◽  
Luis Estevan ◽  
Ismael Vives
Keyword(s):  
Reinforced Concrete ◽  
Frame Analysis ◽  
3D Models ◽  
Frame Structures ◽  
Steel Reinforced Concrete ◽  
Solid Models ◽  
Equivalent Frame ◽  
Concrete Joints ◽  
Critical Phases ◽  
The Moment

A numerical model for the analysis of frame structures that is capable of reproducing the behavior of reinforced concrete (RC) members and steel-reinforced concrete (SRC) members in all steps until collapse by simulating a reduced resistance capacity is presented in this work. Taking into account the solid models obtained in previous research that have been validated by experimental results, moment-curvature graphics were obtained in all steps: elastic, plastic, and post-critical to collapse. Beam models versus 3D models considerably simplified the calculation of frame structures and correctly described both the plastic and post-critical phases. The moment-curvature graph can be used in a simplified frame analysis, from post critical behavior to collapse.

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