Foundation Modeling for Jointed Concrete Pavements

2000 ◽  
Vol 1730 (1) ◽  
pp. 34-42 ◽  
Author(s):  
William G. Davids
Keyword(s):  
Finite Element ◽  
Temperature Gradient ◽  
Load Transfer ◽  
Plain Concrete ◽  
Positive Temperature ◽  
Concrete Pavements ◽  
Finite Element Program ◽  
Joint Load ◽  
Foundation Type ◽  
Dense Liquid

Issues related to the finite element modeling of base and subgrade materials under jointed plain concrete pavements are examined. The threedimensional finite element program EverFE, developed in conjunction with the Washington State Department of Transportation, was employed for the analyses. The relevant modeling capabilities of EverFE are detailed, including the ability to model multiple foundation layers, the incorporation of loss of contact between slab and base, and the efficient iterative solution strategies that make large three-dimensional finite element analyses possible on desktop computers. The results of parametric studies examining the effects of foundation type (layered elastic and dense liquid) and properties on the response of jointed plain concrete pavements subjected to axle and thermal loads are presented. Special attention is paid to the interactions between joint load transfer effectiveness and foundation type, and joint load transfer is shown to change significantly with different foundation models and properties. A consideration of simultaneous thermal and axle loadings indicates that the effect of foundation type and properties on critical slab stresses caused by edge loading and a positive temperature gradient is relatively small. However, the slab response is quite sensitive to foundation type for a combined negative temperature gradient and corner loading. On the basis of these results, use of an equivalent dense liquid foundation modulus in mechanistic rigid pavement analysis or design is not recommended when stiff base layers are present.

Research on Load Transfer Efficiency of GFRP Dowel in Jointed Plain Concrete Pavement

2012 ◽  
Vol 178-181 ◽  
pp. 1152-1155 ◽  
Author(s):  
Luo Ke Li ◽  
Yun Liang Li ◽  
Yi Qiu Tan ◽  
Zhong Jun Xue
Keyword(s):  
Finite Element ◽  
Load Transfer ◽  
Concrete Slab ◽  
Three Dimensional ◽  
Plain Concrete ◽  
Element Model ◽  
Transfer Efficiency ◽  
Engineering Practice ◽  
Concrete Pavements ◽  
Load Transfer Efficiency

In a jointed plain concrete pavements, the dowel bar system are used to provide lateral load transfer across transverse joint. Corrosion of commonly used steel dowel in engineering practice reduces their service life and costs considerable maintenance and repair spending for concrete pavements. The objective of this study focus primarily on the performance of none eroded GFRP dowel on LTE( load transfer efficiency) with the help of a three-dimensional finite-element model. The amount of LTE can be obtained directly from comparing the maximum deflection of the concrete slab and the level tensile stress under the concrete slab. According to the finite element results, the larger-diameter GFRP dowel are found to perform the best in this study.

scholarly journals Effectiveness of Dowels in Concrete Pavement

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1669 ◽  
Author(s):  
Jiri Grosek ◽  
Andrea Zuzulova ◽  
Ilja Brezina
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Load Transfer ◽  
Plain Concrete ◽  
Concrete Pavement ◽  
Successful Outcome ◽  
Concrete Pavements ◽  
The Finite Element Method ◽  
Improve Performance ◽  
Direct Measurements

Dowels are located in transverse joints of Jointed Plain Concrete Pavements (JPCP) and they are used to provide load transfer between individual slabs, reduce faulting and improve performance. Dowels and the concrete itself are under the highest stress in the vicinity of joints; thus, in terms of pavement design, the joints are the weakest points of the whole structure. This study dealt with the drawbacks of JPCP with dowels. The evaluation was based on direct measurements on real airport and motorway pavements and highlights insufficient efficiency of load transfer and its possible causes. The authors present a successful outcome with validation by using the finite element method where high tensile stress values of the surrounding concrete were found.

Three-Dimensional Finite Element Analysis of Jointed Plain Concrete Pavement with EverFE2.2

2003 ◽  
Vol 1853 (1) ◽  
pp. 92-99 ◽  
Author(s):  
William G. Davids ◽  
Zongmu Wang ◽  
George Turkiyyah ◽  
Joe P. Mahoney ◽  
David Bush
Keyword(s):  
Finite Element ◽  
Load Transfer ◽  
Three Dimensional ◽  
Plain Concrete ◽  
Horizontal Shear ◽  
Base Shear ◽  
Transverse Joint ◽  
Dimensional Finite Element ◽  
Joint Load ◽  
Three Dimensional Finite Element

The features and concepts underlying EverFE2.2, a freely available three-dimensional finite element program for the analysis of jointed plain concrete pavements, are detailed. The functionality of EverFE has been greatly extended since its original release: multiple tied slab or shoulder units can be modeled, dowel misalignment or mislocation can be specified per dowel, nonlinear thermal or shrinkage gradients can be treated, and nonlinear horizontal shear stress transfer between the slabs and base can be simulated. Improvements have been made to the user interface, including easier load creation, user-specified mesh refinement, and expanded visualization capabilities. These new features are detailed, and the concepts behind the implementation of EverFE2.2 are explained. In addition, the results of two parametric studies are reported. The first study considers the effects of dowel locking and slab-base shear transfer and demonstrates that these factors can significantly affect the stresses in slabs subjected to both uniform shrinkage and thermal gradients. The second study examines transverse joint mislocation and dowel looseness on joint load transfer. As expected, joint load transfer is greatly reduced by dowel looseness. However, while transverse joint mislocation can significantly reduce peak dowel shears, it has relatively little effect on total load transferred across the joint for the models considered.

scholarly journals Laboratory Characterization of The Load Transfer-Crack Width Relation for Innovative Short Concrete Slabs Pavements

2020 ◽  
Vol 15 (1) ◽  
pp. 232-250 ◽  
Author(s):  
Mauricio Pradena ◽  
Lambert Houben ◽  
Andrés César
Keyword(s):  
Structural Design ◽  
Crack Width ◽  
Load Transfer ◽  
Plain Concrete ◽  
Design Methods ◽  
Transfer Efficiency ◽  
Concrete Slabs ◽  
Concrete Pavements ◽  
Load Transfer Efficiency ◽  
Reduced Scale

Aggregate interlock is the dominant load transfer mechanism in non-dowelled Jointed Plain Concrete Pavements, as the innovative short concrete slabs. Although the Load Transfer Efficiency of this pavement innovation is based on that mechanism, the structural design methods do not relate the Load Transfer Efficiency by aggregate interlock with its direct cause, which is the Crack Width under the joints. The objective of the present article is to characterise in the laboratory the Load Transfer Efficiency−Crack Width relation for innovative short slabs Jointed Plain Concrete Pavements. Additionally, as an alternative to large-scale laboratory tests to study the Load Transfer Efficiency, a practical test on a reduced scale is proposed. The results confirmed that short slabs Jointed Plain Concrete Pavements with high-quality aggregates are able to provide adequate Load Transfer Efficiency (above 70%) without dowels bars. Based on the laboratory results, complemented with previous field data, a Load Transfer Efficiency−Crack Width curve is proposed and made available for structural design methods of short slabs Jointed Plain Concrete Pavements. Finally, the laboratory test on a reduced scale is useful to develop specific Load Transfer Efficiency−Crack Width relations using standard equipment available in traditional concrete laboratories.

scholarly journals Tests on Model Piled Rafts in Sand: Measured Settlements Compared with Finite Element Predictions

2021 ◽  
Author(s):  
Joshua Omer ◽  
Hasan Haroglu
Keyword(s):  
Finite Element ◽  
Load Transfer ◽  
Strain Gauges ◽  
Valuable Insight ◽  
Finite Element Program ◽  
Soil Stiffness ◽  
Piled Raft ◽  
Pile Diameter ◽  
Element Program ◽  
Single Piles

AbstractLaboratory tests were carried out on non-piled rafts, single piles, surface contacting and non surface-contacting piled rafts which were made of aluminum and instrumented with strain gauges and deflection gauges. The foundations were installed in dry sand contained in a large metal tank to minimize boundary effects. Maintained loads were applied to each foundation until failure was closely approached. In parallel, analyses were performed using PLAXIS™ 3-D finite element program to compare the calculated and measured load-settlement trends hence assess the influence of soil stiffness on the foundation behaviour. The results confirmed that group efficiency of non-surface contacting piled increased with increasing pile–pile spacing and approached unity at a spacing equivalent to 8D (D = pile diameter). The data obtained from the strain gauges provided valuable insight into the load-transfer characteristics of different foundations and subsequently proved that the capacity of a surface contacting piled raft is significantly enhanced compared to that of either a non-piled raft or a non-surface contacting piled raft.

Corner loading and curling stress analysis for concrete pavements — an alternative approach

2002 ◽  
Vol 29 (4) ◽  
pp. 576-588 ◽  
Author(s):  
Ying-Haur Lee ◽  
Ying-Ming Lee ◽  
Shao-Tang Yen
Keyword(s):  
Finite Element ◽  
Stress Analysis ◽  
Projection Pursuit ◽  
Structural Response ◽  
Concrete Pavements ◽  
Finite Element Program ◽  
Response Characteristics ◽  
Wide Range ◽  
Bending Stresses ◽  
Wheel Loading

Since corner breaks are one of the major structural distresses in jointed concrete pavements, this research study mainly focuses on the determination of the critical bending stresses at the corner of the slab due to the individual and combination effects of wheel loading and thermal curling. A well-known slab-on-grade finite element program (ILLI-SLAB) was used for the analysis. The structural response characteristics of a slab corner were first investigated. Based on the principles of dimensional analysis, the dominating mechanistic variables were carefully identified and verified. A series of finite element factorial runs over a wide range of pavement designs was carefully selected and conducted. The resulting ILLI-SLAB corner stresses were compared with the theoretical Westergaard solutions, and adjustment factors were introduced to account for this discrepancy. Prediction equations for stress adjustments were developed using a modern regression technique (Projection Pursuit Regression). A simplified stress analysis procedure was proposed and implemented in a user-friendly computer program (ILLISTRS) to facilitate instant stress estimations and practical trial applications.Key words: concrete (rigid) pavements, corner breaks, loading, thermal curling, corner stress.

scholarly journals Fracture modelling of plain concrete using non-local fracture mechanics and a graph-based computational framework

2021 ◽  
Vol 477 (2252) ◽  
pp. 20210398
Author(s):  
P. Thamburaja ◽  
K. Sarah ◽  
A. Srinivasa ◽  
J. N. Reddy
Keyword(s):  
Finite Element ◽  
Plain Concrete ◽  
Element Analysis ◽  
Computational Framework ◽  
Finite Element Program ◽  
Explicit Finite Element ◽  
Element Program ◽  
Non Local ◽  
Material Length Scale ◽  
Material Length

In this article, we developed a thermodynamically consistent non-local microcracking model for quasi-brittle materials with application to concrete. The model is implemented using a novel graph-based finite element analysis (GraFEA) approach that allows for (i) the probabilistic modeling of the growth and coalescence of microcracks, (ii) the modeling of crack closure using a kinematics-based approach, and (iii) the modeling of rate effects on microcracking. The developed theoretical model and its computational framework is also implemented into the dynamics-based Abaqus/Explicit finite element program through a vectorized user-material subroutine interface. We further demonstrate the procedure for obtaining the parameters (including the non-local intrinsic material length scale, which governs the fracture process) and consequently validate the simulations with independent experimental results.

scholarly journals LOAD TRANSFER-CRACK WIDTH RELATION OF NON-DOWELLED JOINTED PLAIN CONCRETE SHORT SLABS

2018 ◽  
Vol 13 (1) ◽  
pp. 40-45 ◽  
Author(s):  
Mauricio PRADENA ◽  
Lambert HOUBEN
Keyword(s):  
Crack Width ◽  
Load Transfer ◽  
Field Measurements ◽  
Plain Concrete ◽  
Cost Effective ◽  
Small Crack ◽  
Concrete Slabs ◽  
Finite Element Program ◽  
Crack Widths ◽  
Aggregate Interlock

Non-dowelled short slabs are a cost-effective innovation of jointed plain concrete pavements. The development of this innovation has been concentrated in their structural performance. Still there is a lack of specific studies of the relation load transfer – crack width, being the crack width at joint the direct cause of the aggregate interlock. Considering that their provision of load transfer relies on aggregate interlock, the objective of the present article is to develop the relationship between the load transfer by aggregate interlock and its direct cause (the crack width) specifically for innovative non-dowelled short concrete slabs pavements. For that, the analysis includes a validated nonlinear aggregate interlock model incorporated in a 3D Finite Element program, laboratory results, and field measurements performed as part of the present investigation. The results show that due to the small crack widths, the short slabs are able to provide adequate load transfer (not less than 70%) even without dowels bars. Indeed, in this case, the load transfer relies on aggregate interlock and the results of the Faultimeter (residual value more than 0) have confirmed this interlocking for crack widths at joints not more than 1.2 mm, which are typical values in short slabs when the joints are activated. For that, the Early Entry saw cutting method needs to be modified or applied as a complementary method to perform the joints. Although in short concrete slabs pavements the provision of load transfer is already guaranteed by the small crack widths at joints, the application of high-quality coarse aggregates provides even higher load transfer.

scholarly journals Mechanical Behavior of Concrete Pavement considering Void beneath Slabs and Joints LTE

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Bangyi Liu ◽  
Yang Zhou ◽  
Linhao Gu ◽  
Dalin Wang ◽  
Xiaoming Huang
Keyword(s):  
Load Transfer ◽  
Joint Stiffness ◽  
Plain Concrete ◽  
Concrete Pavement ◽  
Concrete Pavements ◽  
Void Size ◽  
Fea Model ◽  
Base Course ◽  
Load Transfer Efficiency ◽  
Mesh Convergence

Dowel bars are arranged between two slabs of jointed plain concrete pavements to transfer load between them. The looseness of these dowel bars leads to the decrease of the load transfer efficiency (LTE). Meanwhile, repeated vehicle load can result in void near the joints. In this paper, the behaviors of concrete pavement under the effect of void size and joint stiffness were studied by using ABAQUS software. The FEA model was calibrated for different element parameters based on mesh convergence analysis and validated by comparison with previous studies. The voids beneath slabs were considered in this study, including the loaded slab and unloaded slab. The different effects of base course modulus on the stress of loaded slab are also analysed. It is concluded that the results show that the void size and joint stiffness affect the stress of the loaded plate. Smaller void size and larger joint stiffness will lead to the maximum stress located at the bottom of the loaded slab, and the void size has little effect on the stress of the loaded slab. Otherwise, the larger void size will cause larger stress. The effect of base modulus on stress is similar.

Effect of Concrete Mix Consolidation on Joint Faulting and Load Transfer Efficiency

1996 ◽  
Vol 1544 (1) ◽  
pp. 3-8
Author(s):  
Mustaque Hossain ◽  
John B. Wojakowski
Keyword(s):  
Load Transfer ◽  
Plain Concrete ◽  
Concrete Pavement ◽  
Transfer Efficiency ◽  
Unit Weight ◽  
Concrete Pavements ◽  
Falling Weight Deflectometer ◽  
Rate Of Increase ◽  
Load Transfer Efficiency ◽  
Falling Weight

Six jointed reinforced concrete pavement and one jointed plain concrete pavement test sections on US-69 in Miami County, Kansas, constructed in 1979 have been surveyed annually for faulting for the past 9 years. Falling weight deflectometer tests were conducted in 1995 to assess the load transfer efficiency of the joints. The results show that, in general, as the original concrete density increases due to improved consolidation, the rate of increase of the joint fault depth decreases at doweled joints at a given pavement age. The occurrence of joint faulting is much more severe when load transfer devices are not present; this was observed even for the pavement section built on a nonerodible subbase. Improved consolidation sometimes appeared to help improve load transfer, resulting in a lower rate of faulting. Thus, the mandatory density requirement of 98 percent rodded unit weight, which has been in effect since 1980, has undoubtedly led to better joint performance for concrete pavements in Kansas.

Sign in / Sign up

Export Citation Format

Share Document