A Simplified Concrete Creep and Shrinkage CEB-FIP90 Model in Long-Span Bridge Design

2014 ◽  
Vol 638-640 ◽  
pp. 1059-1062
Author(s):  
Qing Xiang Zeng ◽  
Da Jian Han
Keyword(s):  
Influence Factor ◽  
Shrinkage Strain ◽  
Bridge Design ◽  
Concrete Shrinkage ◽  
Creep Coefficient ◽  
Long Span ◽  
Long Span Bridge ◽  
Shrinkage And Creep ◽  
The Pearl River ◽  
Creep And Shrinkage

The concrete shrinkage strain and creep coefficient calculation method in CEB - FIP MC90 model is briefly introduced. For application convenience in bridge design, a simplified formula for calculation of the concrete shrinkage strain and creep coefficient is derived. Considering the varying range of every influence factor, a correlation analysis for the factor is carried out. And the weights of those factors related to concrete shrinkage and creep coefficient are discussed. Considering the climate characteristics and the bridge structure features in the Pearl River Delta area, the variation ranges of concrete nominal shrinkage strain and nominal creep coefficient are calculated respectively.

Concrete Shrinkage and Creep Effect Prediction Model and the Influence Factors Analysis

2013 ◽  
Vol 756-759 ◽  
pp. 2051-2054 ◽  
Author(s):  
Rui Fang Duan ◽  
Xiu Fen Huang ◽  
He Zhang
Keyword(s):  
Relative Humidity ◽  
Influence Factors ◽  
Shrinkage Strain ◽  
Complex Problem ◽  
Concrete Creep ◽  
Concrete Shrinkage ◽  
Creep Coefficient ◽  
Creep Effect ◽  
Shrinkage And Creep ◽  
Average Relative Humidity

It is a complex problem that forecast and control the shrinkage and creep of concrete and influence on the performance of the structures.Through the conmparion of all kinds of common model,the article have also analysed the main influence factors about the concrete shrinkage and creep effect . The results showed that JTJ 85 model for shrinkage and creep effect tends to conservative calculation; the creep coefficient and shrinkage strain of JTG D62 model and the CEB-FIP model were basically consistent; and ACI 209 model underestimated the concrete shrinkage and creep effect. Theoretical depth of components was more sensitive to concrete shrinkage strain, and creep coefficient was smaller sensitivity; The effect of concrete creep increases with the decreasing of age at loading, when age of loading percentage increased from three to 28 days, the concrete creep effect of the terminal value reduced about 80%; The influence of environment average relative humidity on shrinkage and creep effect is more sensitive, when environment average relative humidity increased from 50% to 80%, creep coefficient nearly reduced about 30%,and shrinkage strain decreased 50%, in comparison, the influence of environment relative humidity chance on the concrete shrinkage effect is greater than that on creep effect.

Simulation Analysis of Shrinkage and Creep for Bowstring Arch Bridge Steel Tube Concrete in Different Specification

2012 ◽  
Vol 178-181 ◽  
pp. 2219-2223 ◽  
Author(s):  
Rong Ling Zhang ◽  
Liang Wang ◽  
Chang An Yang ◽  
Bing Yang ◽  
Chang Yue Zhu ◽  
...  
Keyword(s):  
Simulation Analysis ◽  
Steel Tube ◽  
Analysis Method ◽  
Accurate Calculation ◽  
Element Analysis ◽  
Concrete Shrinkage ◽  
Shrinkage And Creep ◽  
Bridge Steel ◽  
Influence Degree ◽  
Creep And Shrinkage

The actual bowstring arch CFST is taken as the background,the paper using finite element analysis method, researched the shrinkage and creep of combination of steel and concrete structure. Through the use of different countries regulation of shrinkage and creep of concrete, the effects of the structure deflection separately were studied ,then explain the different influence degree of different norms in the calculation of the creep and shrinkage of concrete; The paper also has also put forward the doubt about accurate calculation concrete filled steel tubular structure shrinkage and creep of concrete, it puts forward new requirements for the research and standards about steel tube concrete shrinkage and creep at last.

scholarly journals SHRINKAGE AND CREEP CHARACTERISTICS OF PALM KERNEL SHELL CONCRETE

2020 ◽  
Vol 26 (1) ◽  
pp. 47-56
Author(s):  
ADETUKASI ADESOLA OLAYINKA ◽  
IKPONMWOSA EFE EWAEN
Keyword(s):  
Research Work ◽  
Palm Kernel ◽  
Shrinkage Strain ◽  
Partial Replacement ◽  
Normal Concrete ◽  
Palm Kernel Shell ◽  
Mix Proportion ◽  
Creep Characteristics ◽  
Shrinkage And Creep ◽  
Creep And Shrinkage

This research work evaluates the shrinkage and creep characteristics of concrete containing Palm Kernel Shell (PKS) as partial replacement of natural coarse aggregate. Concrete was mixed at 0.55 water-cement ratio, mix proportion of 1:1:2 and percentage replacement of natural aggregate with PKS at 0%, 25 % and 50%. The creep and shrinkage results of Palm Kernel Shell Concrete (PKSC), increased as the percentage content of PKS increased in the concrete. The maximum creep strain observed for normal concrete, 25 % and 50 % PKS content were 0.00018 mm/m, 0.00057 mm/m and 0.00094 mm/m respectively. The maximum total shrinkage strain recorded for 0%, 25% and 50 % PKS content was 0.00102 mm/m, 0.00183 mm/m and 0.00247 mm/m respectively.

Incorporation of Stress Time Dependence into Failure Projection Modeling of Corroding Bridge Post-Tensioning Tendons

CORROSION ◽  
10.5006/3607 ◽  
2020 ◽  
Vol 76 (11) ◽  
pp. 1088-1091
Author(s):  
William H. Hartt ◽  
Teddy S. Theryo
Keyword(s):  
Time Dependence ◽  
Analytical Modeling ◽  
Initial Value ◽  
Long Span ◽  
Long Span Bridge ◽  
Bridge Structures ◽  
Post Tensioning ◽  
Wire Strand ◽  
Creep And Shrinkage

Post-tensioning (PT) has evolved to become an important technology for designing long span bridge structures. However, tendon failures resulting from wire/strand corrosion have been reported as early as 2 y post construction. In response to this, a recent study introduced and evaluated an analytical modeling approach that projects corrosion-induced wire and strand fractures and tendon failures, given statistics that characterize wire corrosion rate. This past modeling effort assumed that tensile stress in tendons was constant with time at 63% of the guaranteed ultimate tensile strength (GUTS); however, in actuality this stress decreases with time over an assumed 10,000 d (approximately 27 y) from an initial value of about 70% of GUTS to a long-term value in the range 60% to 63% of ultimate at mid-span for a simply supported beam as a consequence of long-term concrete creep and shrinkage and strand relaxation. The present study builds upon this model by incorporating this time dependence of tendon stress into the failure projection modeling. Results are discussed within the context of better understanding bridge tendon integrity issues and corrosion related failure concerns.

Experimental Research on Concrete Shrinkage and Creep for Main Girder of Sutong Continuous Rigid-Frame Bridge

2012 ◽  
Vol 594-597 ◽  
pp. 1547-1551 ◽  
Author(s):  
Yun Tao Zhang
Keyword(s):  
Engineering Application ◽  
Plain Concrete ◽  
Reinforcement Ratio ◽  
Concrete Shrinkage ◽  
Continuous Rigid Frame Bridge ◽  
Rigid Frame ◽  
Shrinkage And Creep ◽  
Rigid Frame Bridge ◽  
Main Girder ◽  
Creep And Shrinkage

In order to obtain shrinkage and creep of HPC used in Sutong continuous rigid-frame bridge, shrinkage and creep of plain concrete and RC are investigated under natural environment over two years. Reinforcement ratio 0.76% is close to that of the middle span. Loading stress of creep test is about 15MPa, which is near the maximum stress of the bridge. Four loading ages, 7d, 14d, 21d and 28d, were used to simulate different loading ages in construction. The curves of creep and shrinkage were fitted from test values. The results show the test values of creep and shrinkage were less than the current Chinese bridge code JTG D62-2004, and the creep and shrinkage of RC is less than plain concrete. If the reinforcement ratio is low, reinforcement exerts less influence on creep and shrinkage, and the influence of reinforcement can be neglected in engineering application. Reinforcement can effectively reduce creep and shrinkage if the reinforcement ratio is high.

scholarly journals Modeling Shrinkage and Creep for Concrete with Graphene Oxide Nanosheets

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3153 ◽  
Author(s):  
Chen ◽  
Xu ◽  
Hua ◽  
Zhou ◽  
Wang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Concrete Strength ◽  
Shrinkage Strain ◽  
Influential Factors ◽  
Graphene Oxide Nanosheets ◽  
Model Accuracy ◽  
Modified Model ◽  
Creep Coefficient ◽  
Shrinkage And Creep ◽  
Application Scope

In this study, the shrinkage and creep of concrete containing graphene oxide (GO) nanosheets were experimentally and theoretically investigated. Experiments for the shrinkage and creep of concrete with 0.02% and 0.08% GO nanosheets by the weight of cement and common concrete were carried out. Subsequently, the influence of GO nanosheets on the shrinkage and creep of concrete was analyzed and discussed. A modified model was developed to accurately predict the shrinkage and creep of concrete containing GO nanosheets after models for predicting shrinkage and creep of common concrete were compared and the influential factors and application scope were determined. Results indicate that: (1) GO nanosheets can increase the shrinkage strain and reduce the creep coefficient of concrete, and (2) a modified ACI209 (92) model can accurately predict the shrinkage and creep of concrete containing GO nanosheets. Factors considering concrete strength can be introduced in the model to improve the model accuracy.

The Experimental Study on Creep and Shrinkage of High Strength Concrete with Fly Ash

2013 ◽  
Vol 639-640 ◽  
pp. 423-426 ◽  
Author(s):  
Jian Qun Wang ◽  
Zhi Fang ◽  
Zhi Jian Tang
Keyword(s):  
Fly Ash ◽  
Prestressed Concrete ◽  
High Strength Concrete ◽  
Large Scale ◽  
Influence Factor ◽  
Concrete Structures ◽  
High Strength ◽  
Strength Concrete ◽  
Shrinkage And Creep ◽  
Creep And Shrinkage

Shrinkage and creep characteristics of concrete are significant factors in the design of prestressed concrete structures. With large scale/span concrete structures developed, the fly ash or other blends are added into high strength concrete to improve the mechanical properties and workability. As a result, the existing shrinkage and creep predicting models have certain limitations. The creep and shrinkage behavior of high strength concrete with fly ash are studied in this paper. Proper predicting model for shrinkage and creep of high strength concrete is recommended. The influence factor of fly ash is proposed as well. These conclusions would be of great useful for structures with fly ash concrete.

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