scholarly journals Modelling of Bonded Post-Tensioned Concrete Cantilever Beams under Flexural Loading

2017 ◽  
Vol 3 (7) ◽  
pp. 463-479
Author(s):  
Abbas Mohammed ◽  
Khattab Saleem Abdul-Razzaq ◽  
Nildem Tayşi ◽  
Awat FAQE
Keyword(s):  
Reinforced Concrete ◽  
Three Dimensional ◽  
Offshore Structures ◽  
Cantilever Beams ◽  
Fe Method ◽  
Flexural Strengthening ◽  
Long Span ◽  
Small Depth ◽  
Package Program ◽  
Post Tensioned

Prestressing is widely used technic all over the world for constructions of buildings, bridges, towers, offshore structures etc. due to its efficiency and economy for achieving requirements of long span with small depth. It is used for flexural strengthening of reinforced concrete structures for improving cracking loads and decreasing deflections due to service loads. There are two methods for prestressing (pre-tensioning and post-tensioning). In this paper, a three-dimensional nonlinear Finite Element (FE) method is used to determine the behaviour of Post-Tensioned (PT) concrete cantilever beams with different tendon profiles. Numerical analyses ANSYS package program is used for analysis of beams. The results from FE analysis is verified by experimental reference test result and good agreement is achieved. This paper is focused on the effect of different tendon profiles on the flexural behaviour of Bonded Post Tensioned (BPT) reinforced concrete cantilever beams. Six models with different tendon profiles are investigated. These models are without tendons, two tendons at the bottom, middle, top, parabolic tendons with one draped point and two draped points. Failure loads, deflections, and load versus deflection relationships for all models are examined and it is seen that the beam with one draped tendon profile shows a highest performance.

scholarly journals FE Models of GFRP and CFRP Strengthening of Reinforced Concrete Beams

2009 ◽  
Vol 2009 ◽  
pp. 1-13 ◽  
Author(s):  
Kasidit Chansawat ◽  
Tanarat Potisuk ◽  
Thomas H. Miller ◽  
Solomon C. Yim ◽  
Damian I. Kachlakev
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Concrete Beams ◽  
Three Dimensional ◽  
Full Scale ◽  
Reinforced Concrete Beams ◽  
Flexural Strengthening ◽  
Frp Composites ◽  
Strengthened Beam ◽  
Three Dimensional Finite Element

Three-dimensional finite element (FE) models are developed to simulate the behavior of full-scale reinforced concrete beams strengthened with glass and carbon fiber-reinforced polymer sheets (an unstrengthened control beam, a flexural-strengthened beam, a shear-strengthened beam, and a beam with both shear and flexural strengthening). FE models use eight-node isoparametric elements with a smeared cracking approach for the concrete and three-dimensional layered elements to model the FRP composites. Analysis results are compared with data obtained from full-scale beam tests through the linear and nonlinear ranges up to failure. It was found that the FE models could identify qualitatively trends observed in the structural behavior of the full-scale beams. Predicted crack initiation patterns resemble the failure modes observed for the full-scale beam tests.

Numerical Analysis about Flexural Strengthening Reinforced Concrete Beams by Bolting Steel Plates

2011 ◽  
Vol 217-218 ◽  
pp. 1658-1662
Author(s):  
Xiao Dan Liu ◽  
Sheng Wang Hao ◽  
Yan Yan Li
Keyword(s):  
Reinforced Concrete ◽  
Steel Plate ◽  
Concrete Beams ◽  
Plate Thickness ◽  
Three Dimensional ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Flexural Strengthening ◽  
Beam Surface ◽  
Anchor Bolts

This paper presents a three-dimensional nonlinear finite elemental analysis about the reinforcement concrete beams strengthened by bolting steel plate, which is a new strengthening method by anchoring plate to beam surface but not using any glue to help bonding. The contact effects between the steel plate with reinforced concrete beam surface was simulated by developing the contact elements. The effects of the plate thickness and the collocation of anchor bolts were investigated. The damage evolution about variable collocation of anchor bolts were investigated. It is declared that the collocation of anchor bolts play an obvious effects on the flexural capacity of strengthened beams, but the plate thickness give a little influence on it.

scholarly journals Flexural strengthening of beams using post-tensioned metal straps fully wrapped around steel channels anchored to normal steel reinforced concrete beams

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0253816
Author(s):  
Wrya Abdullah ◽  
Serwan Khwrshid Rafiq
Keyword(s):  
Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Load Carrying Capacity ◽  
Factors Affecting ◽  
Flexural Strengthening ◽  
Steel Reinforced Concrete ◽  
Load Carrying ◽  
Main Variable ◽  
Novel Method ◽  
Post Tensioned

The efficacy of post-tensioned metal straps PTMS, wrapped around steel channels anchored to normal reinforced concrete (R.C) beams is tested in increasing the flexural capacity of the beams. For this purpose, nine normal R.C beams with dimensions of 160 mm x 240 mm x 2100 mm are constructed to fail in bending. The location and the number of the straps are considered as the main variable. It is found that using PTMS can enhance the load-carrying capacity of the beam by 29% to 63%. The decisive factors affecting the increase are the location of the straps (at the bottom or sides), shape of the flange and web edges (squared or rounded) and alignment of the flanges (vertical or inclined). A complete guide can be found in the paper as it is a novel method of strengthening beams which can be applied to the beams cast in place with integral slabs.

scholarly journals Post-Tensioning Steel Rod System for Flexural Strengthening in Damaged Reinforced Concrete (RC) Beams

2018 ◽  
Vol 8 (10) ◽  
pp. 1763
Author(s):  
Swoo-Heon Lee ◽  
Kyung-Jae Shin ◽  
Hee-Du Lee
Keyword(s):  
Reinforced Concrete ◽  
Load Resistance ◽  
Reinforced Concrete Beams ◽  
Design Parameters ◽  
Flexural Strengthening ◽  
Three Point Bending ◽  
Rod System ◽  
Load Carrying ◽  
Post Tensioning ◽  
Post Tensioned

In this study, a post-tensioning method using externally unbonded steel rods was applied to pre-damaged reinforced concrete beams for flexural strengthening. Nine simply-supported beams, three reference beams and six post-tensioned beams, were subjected to three-point bending. The design parameters observed in this study were the amount of tension reinforcements (3-D19, 4-D19, and 2-D22 + 2-D25; “D” indicates the nominal diameter of the rebar) and the diameters of the external rod (φ22 mm and φ28 mm). A V-shaped profile with a deviator at the bottom of the mid-span was applied to the pre-damaged beams, and a post-tensioning force was added to overcome the low load resistance and deflection already incurred in the pre-loading state. The post-tensioning force caused by tightening the nuts at the anchorage corresponded to a strain of 2000 με in the external rods; this value was approximately equal to the strain caused by torque that two adults can apply conveniently. The post-tensioning system increased the load-carrying capacity and flexural stiffness by approximately 40–112% and 28–73%, respectively, when compared with the control beams. However, the external rods did not yield in the post-tensioned beam with larger steel reinforcements and external steel rods. The external rod with the larger diameter increased the flexural strength more effectively.

Analysis of Reinforced Concrete Culvert considering Concrete Creep and Shrinkage

1996 ◽  
Vol 1541 (1) ◽  
pp. 120-126
Author(s):  
Charles J. Oswald
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Cross Sections ◽  
Soil Structure ◽  
Silty Clay ◽  
Soil Pressure ◽  
Concrete Creep ◽  
Long Span ◽  
Creep And Shrinkage ◽  
Good Agreement

Measurements made on a long span reinforced concrete arch culvert under 7.3 m (24 ft) of silty clay backfill were compared with results from finite-element analyses of the soil-structure system using the CANDE finite-element code. The culvert strains and deflections and the soil pressure on the culvert were measured during construction and during the following 2.5 years at three instrumented cross sections. The CANDE program was modified to account for the effects of concrete creep and shrinkage strains after it was noted that the measured postconstruction culvert deflection and strains increased significantly whereas the measured soil pressure on the culvert remained relatively constant. Good agreement was generally obtained between measured and calculated values of the culvert strain and deflection and the soil pressure during the entire monitoring period after the code was modified.

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