Influence of long‐term creep on prestressed concrete beams in relation to deformations and structural resistance: Experiments and modeling

2020 ◽  
Vol 21 (4) ◽  
pp. 1458-1474
Author(s):  
Nicky Reybrouck ◽  
Tim Van Mullem ◽  
Luc Taerwe ◽  
Robby Caspeele
Keyword(s):  
Prestressed Concrete ◽  
Concrete Beams ◽  
Structural Resistance ◽  
Term Creep

Experimental Study on Creep Behavior of Prestressed Concrete Beams with Pretensioned Bent-Up Tendons for 600 Days

2013 ◽  
Vol 438-439 ◽  
pp. 649-653
Author(s):  
Jun Wang ◽  
Li Hui Li
Keyword(s):  
Prestressed Concrete ◽  
Influence Factor ◽  
Concrete Beams ◽  
Time History ◽  
Outdoor Environment ◽  
Creep Coefficient ◽  
Code Model ◽  
Straight Line ◽  
China Academy

The prestressed concrete beam with pretensioned bent-up tendons combines many advantages of the straight-line pretensioned prestressed beams and the curvilinear posttensioned beams. To improve its application in bridges, long-term deformation should be exactly predicted and controlled. Three prestressed concrete beams with pretensioned bent-up tendons XPB1,XPB2, XPB3 were fabricated, and XPB1 and XPB3 were put in standard curing room, but XPB2 were put in outdoor environment. All the experimental beams were simple supported under long-term loads. Their deformation such as creep strain and long-term deflection in mid-span section were observed about 600 days. By analyzing the influence factor and time-history law of creep coefficient and long-term coefficient, creep coefficient equation of the test beams was fitted and compared with the code model such as ACI209R-92, CEB-FIP MC90 and 86 model proposed by China Academy of Building Research, and the ±10% margin error of this model was pointed out. All these results may offer the initial value of long-term deformation of the prestressed concrete beams with pretensioned bent-up tendons.

Long-Term Behavior of CFRP Prestressed Concrete Beams

PCI Journal ◽  
2003 ◽  
Vol 48 (2) ◽  
Author(s):  
Abass Braimah ◽  
Mark F. Green ◽  
Khaled A. Soudki
Keyword(s):  
Prestressed Concrete ◽  
Concrete Beams ◽  
Long Term Behavior

Effects of cyclic loading on the long-term deflection of prestressed concrete beams

2013 ◽  
Vol 12 (6) ◽  
pp. 739-754 ◽  
Author(s):  
Lihai Zhang ◽  
Priyan Mendis ◽  
Wong Chon Hon ◽  
Sam Fragomeni ◽  
Nelson Lam ◽  
...  
Keyword(s):  
Cyclic Loading ◽  
Prestressed Concrete ◽  
Concrete Beams

Time-Dependent Finite Element Analysis of Prestressed Concrete Beams

2015 ◽  
Vol 1096 ◽  
pp. 548-552
Author(s):  
Ting Liu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Prestressed Concrete ◽  
Concrete Beams ◽  
Tensile Force ◽  
Time Dependent ◽  
Test Results ◽  
Element Analysis ◽  
Finite Element Software

Based on ABAQUS general finite element software, UMAT Fortran subroutine is compiled to estimate the long-term deflections of prestressed concrete beams. And the calculated values using the software corresponded well with the laboratory results. By generalizing key parameters impact on long−term deflections of prestressed concrete beams, time-dependent finite element analysis was conducted. Taking type of concrete, concrete grade, age of concrete when the initial stress was applied, effective prestressing tensile force, type of prestressed tendon, reinforcement ratio for nonprestressed compression steel reinforcement and mean relative humidity into account, a simplified formula for long-term deflection of prestressed concrete beam at midspan was suggested. And the calculated values using the suggested formula corresponded well with the laboratory and filed test results. The errors were within 10%. However, the calculated errors using the common codes were larger, which resulted in the unsafe values.

Integrity Strain Response Analysis of a Long Span Cable-Stayed Bridge

2009 ◽  
Vol 413-414 ◽  
pp. 775-783 ◽  
Author(s):  
Shun Long Li ◽  
Hui Li ◽  
Jin Ping Ou ◽  
Hong Wei Li
Keyword(s):  
Prestressed Concrete ◽  
Probability Model ◽  
Temperature Data ◽  
Reference Points ◽  
Reliability Estimation ◽  
Response Analysis ◽  
Strain Response ◽  
Loading Test ◽  
Term Creep

This paper presents the analysis of strain time histories measured by structural health monitoring system. The main objective of this study is to prepare data for reliability estimation of main components as well as the entire structural system. The strain and corresponding temperature data is collected at the following stages: closure segment reconstruction stage and operating stage. The strain monitoring of the closure segment during the reconstruction stage provided valuable information on early-life strain development and reference characteristics for events such as post tensioning and temperature change. These lessons learnt from the reconstruction monitoring can be used for understanding subsequent bridge behavior, including damage detection and reference points of subsequent monitoring. Specially, the loading test results reveal the effectiveness and correctness of the strain acquiring system and provide evidence for reliable long-tem monitoring. Strain and temperature data have been recorded at sampling frequency of 62.5Hz since loading test, which would provide information linear stress-strain relationships. The long-term creep and shrinkage model were provided by Code for Design of Highway Reinforced Concrete and Prestressed Concrete Bridge and Culverts (JTG D62-2004). Through the statistical analysis of the online strain response, the probability model of long-term performance under environmental and random traffic loading are obtained which gives the potential of its application of reliability based assessment on cable stayed bridges where they evaluated the reliability of elements such as cables and stiffening girder.

Experimental investigation on long-term behavior of prestressed concrete beams under coupled effect of sustained load and corrosion

2020 ◽  
Vol 23 (12) ◽  
pp. 2587-2596
Author(s):  
Jun Yang ◽  
Tong Guo ◽  
Aiqun Li
Keyword(s):  
Experimental Investigation ◽  
Prestressed Concrete ◽  
Concrete Beams ◽  
High Stress ◽  
Past Research ◽  
Load Level ◽  
Sustained Load ◽  
Coupled Effect ◽  
Long Term Behavior

Prestressed concrete beams are widely used in construction, while they may be attacked by the corrosion medium during the service. Past research works show that coupled effect of high stress and corrosion can significantly deteriorate the performance of prestressed concrete structures. This article presents an experimental investigation on long-term behavior of prestressed concrete beams under the coupled effect of sustained load and corrosion. During the accelerated corrosion process, six prestressed concrete beams were subjected to different levels of sustained loads, and time-dependent prestress loss and concrete stains were recorded and analyzed. It is observed that the local corrosion (i.e. pitting corrosion) of the steel strands was significantly affected by the sustained load level, and the coupled effect led to more serious damage on the beams than individual sustained load or corrosion. Bending loads were finally applied to investigate the influence of corrosion on flexural capacities of these beams. It was found that the flexural capacities and failure mode of the beams were significantly influenced by corrosion. Meanwhile, the corrosion has more significant effect on tension strength of strands rather than bond strength.

Sign in / Sign up

Export Citation Format

Share Document