scholarly journals Structural Performance Assessment of Airfield Concrete Pavements Based on Field and Laboratory Data

2021 ◽  
Vol 6 (12) ◽  
pp. 173
Author(s):  
Konstantinos Gkyrtis ◽  
Angeliki Armeni ◽  
Christina Plati ◽  
Andreas Loizos

Maintenance interventions and rehabilitation actions in airfield pavements are time-consuming and adversely affect pavements’ serviceability (i.e., airport closures), with a profound impact on the airport economics. Once a pavement is constructed, a robust asset management prerequisites systematic and accurate knowledge of pavement condition throughout its service life. Evaluating a pavement’s structural capacity in the field involves the integration of multiple Non-Destructive Testing (NDT) systems, with the Falling Weight Deflectometer (FWD) being the most indicative NDT system for pavement evaluation. The purpose of the present study is to develop a methodology for the assessment of airfield concrete pavements. A new and non-trafficked Jointed Plain Concrete Pavement (JPCP), facing early-life cracks shortly after a runway’s expansion activities, was utilized for the investigation. Multiple types of data collected in the field, including deflections, load transfer efficiency at joints and cracks, concrete thickness through coring as well as data retrieved in the laboratory (concrete’s flexural strength), helped to define the pavement’s performance and assess its damage potential. Overall, the integration of such data can provide the related airport authorities the necessary information in order to make a rational asset management and enhance the efficiency of airfield infrastructures. The methodology is applicable for both new and in-service pavements.

Author(s):  
Neeraj Buch ◽  
Dan G. Zollinger

The results of an in-depth study of factors that affect dowel looseness in jointed concrete pavements are presented. The laboratory investigation revealed the influence of aggregate type (in relation to oxide content), aggregate texture and shape, bearing stress (dowel diameter and crack width), load magnitude, and number of load cycles on the magnitude of dowel looseness and the subsequent loss in load transfer efficiency across saw-cut joints. A discussion is included on the development of an empirical-mechanistic dowel looseness prediction model based on the experimental results. Results of the sensitivity analysis of the dowel looseness prediction model (using laboratory data) are also presented. An associated scope of this research was to develop a relationship between dowel looseness and loss of load transfer efficiency. The sequential use of the dowel looseness prediction model and its relationship to load transfer efficiency allows the design engineer to predict load transfer characteristics of a joint, based on calculated (or measured) dowel looseness. The framework suggested to predict dowel looseness can then be incorporated into a fault prediction model for doweled joints.


2012 ◽  
Vol 178-181 ◽  
pp. 1152-1155 ◽  
Author(s):  
Luo Ke Li ◽  
Yun Liang Li ◽  
Yi Qiu Tan ◽  
Zhong Jun Xue

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.


2020 ◽  
Vol 15 (1) ◽  
pp. 232-250 ◽  
Author(s):  
Mauricio Pradena ◽  
Lambert Houben ◽  
Andrés César

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.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Bangyi Liu ◽  
Yang Zhou ◽  
Linhao Gu ◽  
Dalin Wang ◽  
Xiaoming Huang

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.


Author(s):  
Mustaque Hossain ◽  
John B. Wojakowski

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.


Author(s):  
William G. Davids

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.


Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1669 ◽  
Author(s):  
Jiri Grosek ◽  
Andrea Zuzulova ◽  
Ilja Brezina

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.


2020 ◽  
Vol 12 (21) ◽  
pp. 9153
Author(s):  
Andrés César ◽  
Mauricio Pradena

Concrete pavements are characterized by their high durability and low conservation costs. However, concrete production causes large amounts of harmful emissions. In this context, short slab pavements allow us to reduce the slab thickness and the amount of concrete used in their construction. These benefits are only valid if the design assumptions are fulfilled, one of which is the provision of enough Load Transfer Efficiency (LTE) by the aggregate interlock. However, the current design method for short slabs does not relate the LTE with the Crack Width (CW) under the joints. This can jeopardize the sustainable benefits of short slabs. The objective of this study is to propose a method to develop the LTE–CW relationship for the short slabs’ design. The sustainable and accessible approach adopted in the proposal represents a paradigm shift compared to the traditional methods, which are limited to laboratories with sufficient resources to perform real-scale testing. The results show that it is possible to develop the LTE–CW relation in a sustainable manner. Furthermore, the aggregates that fulfill the technical specifications for pavements provide enough LTE when most of the joints are activated. When that happens, short slab pavements reduce environmental and human health impacts by 33% and 26%, respectively.


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