Structural Analysis for APT Sections Based on Deflection Parameters

2019 ◽  
Vol 2673 (3) ◽  
pp. 313-322 ◽  
Author(s):  
Edgar Camacho-Garita ◽  
Robinson Puello-Bolaño ◽  
Piero Laurent-Matamoros ◽  
José P. Aguiar-Moya ◽  
Luis Loria-Salazar
Keyword(s):  
Costa Rica ◽  
Structural Condition ◽  
Pavement Management ◽  
System Level ◽  
Radius Of Curvature ◽  
Condition Indicators ◽  
Structural Capacity ◽  
Pavement Layers ◽  
Pavement Structures ◽  
Falling Weight

This paper reviews the use of pavement structural condition indicators determined through deflection measurements as a means to monitor structural capacity. The deflection measurements were performed with a road surface deflectometer and a falling weight deflectometer on the various test tracks of an accelerated pavement test (APT) facility. The indicators estimation was based on the deflection data collected from different structures, and it was observed that it is feasible to improve the backcalculation analysis and help overcome some of the limitations associated with such a procedure. For this research, Radius of Curvature, AREA, Normalized AREA, BLI (Upper layers), MLI (Middle layers), and LLI (Lower layers) were the analyzed parameters. Each parameter is related to the structural condition of particular pavement layers. Therefore, the parameters allow general characterization of the pavement layers, and make it possible to detect deteriorated layers. The pavement structures were trafficked by means of an APT at the PaveLab facility at the University of Costa Rica. The deflection parameters were calculated through the APT data, showing the possible use of these indicators at the pavement management system level in Costa Rica, helping the categorization of the pavement structures in service, mainly because the parameters require few input data, and are useful where the available structural condition information is limited. The data presented in this paper show the variation of the different condition indicators throughout the service life of the analyzed pavement structures. The data are also used to compare different structures, their characteristics, and the change in their stiffness associated with damage.

Estimated remaining fatigue life of flexible pavements based on the normalized comprehensive area ratio deflection parameter

2020 ◽  
Vol 47 (5) ◽  
pp. 546-555
Author(s):  
Karthikeyan Loganathan ◽  
Mayzan M. Isied ◽  
Ana Maria Coca ◽  
Mena I. Souliman ◽  
Stefan Romanoschi ◽  
...  
Keyword(s):  
Simulation Analysis ◽  
Area Ratio ◽  
Pavement Management ◽  
Falling Weight Deflectometer ◽  
Structural Capacity ◽  
Pavement Management Systems ◽  
Pavement Structures ◽  
Traffic Disturbance ◽  
Falling Weight

A lot of pavement deflection data are available that may be utilized as a tool to evaluate the structural capacity of pavement structures at network and project levels. Falling weight deflectometer (FWD) is one of the most widely utilized devices in pavement deflection testing. Under FWD testing, deflections generated at several lateral locations as a result of surface loading application are recorded. One of the major downsides of the static FWD testing is the traffic disturbance due to the required lane closures during testing. As an effort to reduce the amount of the required FWD testing on the network level, this study aims to run an advanced computer simulation analysis to mimic the FWD deflection bowl obtained from the field. The entire simulated FWD deflection bowl was utilized in the development of the new comprehensive pavement deflection bowl area parameters. The tensile strain at the bottom of the asphalt layer was successfully related to the developed normalized comprehensive area ratio parameter ([Formula: see text]) and to the number of load repetitions to fatigue failure. The newly developed parameter was evaluated utilizing data for 35 long term pavement performance sections in Texas. The newly developed [Formula: see text] can be easily implemented and utilized as a tool in any pavement management systems.

Pavement Structural Capacity from Traffic Speed Deflectometer for Network Level Pavement Management System Application

2019 ◽  
Vol 2673 (2) ◽  
pp. 456-465 ◽  
Author(s):  
Mahdi Nasimifar ◽  
Senthilmurugan Thyagarajan ◽  
Sarah Chaudhari ◽  
Nadarajah Sivaneswaran
Keyword(s):  
Management System ◽  
Structural Condition ◽  
Pavement Management ◽  
Pavement Design ◽  
Pavement Management System ◽  
Design Engineers ◽  
Structural Capacity ◽  
Traffic Speed ◽  
Falling Weight Deflectometers ◽  
Falling Weight

Structural number (SN) represents the structural capacity of a flexible pavement system to sustain anticipated traffic and is among the structural indices most commonly used by pavement design engineers in the U.S. Effective structural number (SNeff) is an indicator of structural capacity of in-service pavement sections and is conventionally estimated from nondestructive testing (NDT) device data such as falling weight deflectometers (FWDs) using methods such as suggested by AASHTO. In addition to pavement design, structural condition is a critical input for the selection of maintenance and rehabilitation strategies in pavement management system (PMS) application. However, use of SN in network level application has not been practical because of limitations of FWD such as stop-and-go operation, lane closures, and low testing frequency. The traffic speed deflectometer (TSD), a continuous deflection device, has recently been gaining worldwide application as a reliable NDT device for network level PMS applications. The objective of this study is to develop a practical approach to compute and utilize SN of in-service flexible pavements from TSD data for network level PMS applications. The study is based on the fundamental that, for the same pavement, SNeff from the TSD using the proposed method should be in good agreement with SNeff from the FWD using AASHTO method. The developed method was field validated with TSD and FWD data collected at in-service pavement sections. In addition, the use of structural number ratio, defined as a ratio of SNeff to required SN, in network level prioritization of structural capacity improvements was illustrated.

Evaluation of inverted pavement by structural condition indicators from falling weight deflectometer

2022 ◽  
Vol 319 ◽  
pp. 125991
Author(s):  
Xi Jiang ◽  
Jay Gabrielson ◽  
Baoshan Huang ◽  
Yun Bai ◽  
Pawel Polaczyk ◽  
...  
Keyword(s):  
Structural Condition ◽  
Falling Weight Deflectometer ◽  
Condition Indicators ◽  
Falling Weight

Protocol for FWD Data Collection at Network-Level Pavement Management in Iran

2018 ◽  
Vol 2672 (40) ◽  
pp. 68-77 ◽  
Author(s):  
Narges Matini ◽  
Nader Tabatabaee ◽  
Mojtaba Abbasghorbani
Keyword(s):  
Management System ◽  
Condition Index ◽  
Structural Condition ◽  
Pavement Management ◽  
Pavement Management System ◽  
Potential Safety ◽  
Time Required ◽  
Falling Weight Deflectometers ◽  
Ground Penetrating ◽  
Falling Weight

The objective of this study was to develop an approach for incorporating techniques used to interpret and evaluate deflection data for network-level pavement management system applications. A national pavement management system is being developed in Iran and the use of falling weight deflectometers (FWDs) at the network level was deemed necessary to compensate for the lack of vital construction history data in the pavement inventory. Because FWD measurements disrupt traffic flow and are a potential safety hazard, it is imperative to increase the interval between FWD testing points as much as possible to allow scanning of the entire 51,000 km network of freeways, highways, and major roads in a reasonable time span with the least traffic disruption. A project-level dataset at 0.2 km intervals in different environments and diverse traffic categories was selected for analysis. In addition, data from continuous ground-penetrating radar was collected concurrently and compared with a limited number of cores. The overall analysis included evaluation of interval variation, segmentation, the structural condition index (SCI), and layer moduli calculated using the AASHTO and ELMOD methods. The analysis was done to determine the optimum interval between test points. Analysis showed that the collection intervals could be increased from 0.2 to 0.6 km. Subsequently, the applicability and time efficiency of the network-level intervals were verified by calculating overlay thickness and time required.

Prediction of Pavement Remaining Life

1996 ◽  
Vol 1524 (1) ◽  
pp. 137-144 ◽  
Author(s):  
T. S. Vepa ◽  
K. P. George ◽  
A. Raja Shekharan
Keyword(s):  
Data Base ◽  
Management System ◽  
Flexible Pavements ◽  
Information Management System ◽  
Pavement Management ◽  
Remaining Life ◽  
Structural Capacity ◽  
System Data ◽  
Performance Project ◽  
Falling Weight

The evaluation of remaining life is necessary to make optimal use of the structural capacity of in-service pavements. It simply represents the useful life left in the pavement until a failure condition is reached. Knowledge of remaining life facilitates decision making in regard to strategies for reconstruction-rehabilitation of roads, thereby leading to the efficient use of existing resources. Several methods proposed or used by various agencies to estimate the remaining lives of pavements are reviewed. They are classified under two categories: functional and structural. Making use of the Mississippi Department of Transportation pavement management system data base, survivor curves are developed for seven classes of flexible pavements with from thin to thick structures. By using these survivor curves a novel method for estimating remaining life is proposed. The reasonableness of the selected methods is examined by putting them to use in calculating the remaining lives of each of eight rigid and flexible pavement sections, all of them from the Mississippi global positioning system sections of the Strategic Highway Research Program–Long-Term Pavement Performance project (LTPP). With the structural details, falling weight deflectometer deflection data, and the distress information compiled from the LTTP information management system data base, the authors use two and four methods for rigid and flexible pavements, respectively, to determine the remaining lives. The remaining lives calculated by two methods for rigid pavements are comparable. Three of four methods for flexible pavements also generated comparable remaining lives. The authors were encouraged by the results and recommend that the survivor curve approach be explored further for network-level remaining life calculations. The reliabilities of various techniques currently available for the remaining life calculation are discussed.

Assessment of Falling Weight Deflectometer Data for Stabilized Flexible Pavements

2000 ◽  
Vol 1709 (1) ◽  
pp. 19-25 ◽  
Author(s):  
Alexander K. Appea ◽  
Imad L. Al-Qadi
Keyword(s):  
Resilient Modulus ◽  
Ground Truth ◽  
Monitoring And Evaluation ◽  
Structural Condition ◽  
Base Layer ◽  
Falling Weight Deflectometer ◽  
Structural Capacity ◽  
Pavement Monitoring ◽  
Aggregate Base ◽  
Falling Weight

Backcalculation of pavement moduli through the utilization of the falling weight deflectometer (FWD) is used for pavement monitoring and evaluation. The performance and structural condition of nine flexible pavement test sections built in Bedford County, Virginia, have been monitored over the past 5 years using FWD. The nine sections include three groups with aggregate base layer thicknesses of 100, 150, and 200 mm, respectively. Sections 1, 4, and 7 are control, whereas Sections 2, 5, 8 and 3, 6, 9 are stabilized with geotextiles and geogrids, respectively. The FWD testing used five double-load drops ranging from 26.5 to 58.9 kN. The deflection basins obtained from the testing have been analyzed using the ELMOD backcalculation program to find the pavement structural capacity and to detect changes in the aggregate resilient modulus. The analysis shows a reduction in the backcalculated resilient modulus of the 100-mmthick base layer. The reduction was 33 percent over 5 years for the nonstabilized section compared with the geosynthetically stabilized section. The reduction in base layer resilient modulus may have resulted from subgrade fine migration into this layer as confirmed by excavation. The study confirms the effectiveness of using woven geotextile as a separator in a pavement system built over weak subgrade. This supports the continuous rutting measurements and ground truth excavation conducted in late 1997.

Evaluation and Validation of a Model for Predicting Pavement Structural Number with Rolling Wheel Deflectometer Data

2015 ◽  
Vol 2525 (1) ◽  
pp. 13-19 ◽  
Author(s):  
Mostafa A. Elseifi ◽  
Kevin Gaspard ◽  
Paul W. Wilke ◽  
Zhongjie Zhang ◽  
Ahmed Hegab
Keyword(s):  
Pavement Management ◽  
Average Error ◽  
Falling Weight Deflectometer ◽  
Department Of Transportation ◽  
Data Set ◽  
The Road ◽  
Average Prediction Error ◽  
Structural Capacity ◽  
Rolling Wheel ◽  
Falling Weight

Because of costs and the slow test process, the use of structural capacity in pavement management activities at the network level has been limited. The rolling wheel deflectometer (RWD) was introduced to support existing nondestructive testing techniques by providing a screening tool for structurally deficient pavements at the network level. A model was developed to estimate structural number (SN) from RWD data obtained in a Louisiana study. The objective for this study was to evaluate the use of the Louisiana model to predict structural capacity in Pennsylvania and to compare the results with those of existing methods. RWD testing was conducted on 288 mi of the road network in Pennsylvania, and falling weight deflectometer (FWD) testing and coring were conducted on selected sites. The prediction from a model used to estimate SN from RWD deflection data was compared statistically with the prediction obtained from FWD testing and from roadway management system records used by the Pennsylvania Department of Transportation to calculate SN. The results of this analysis validated the use of the model to estimate the pavement SN according to RWD deflection data. In general, the predicted SN was in agreement with the SN calculated from the FWD. The original model with the fitted coefficients developed for Louisiana showed an average prediction error of 27%. However, after the model was refitted to the data set from Pennsylvania, the average error dropped to 19%. Results indicated that the model developed for SN prediction from the RWD provided an adequate prediction of SN for conditions different from those for which it was developed in Louisiana.

Evaluation of the structural capacity of rigid pavements at the network level

2019 ◽  
Vol 46 (5) ◽  
pp. 439-447
Author(s):  
M. Saleh ◽  
J.D. van der Walt
Keyword(s):  
Evaluation Method ◽  
Structural Condition ◽  
Rigid Pavement ◽  
Structural Capacity ◽  
Overall Evaluation ◽  
Actual Field ◽  
Pavement Structure ◽  
Base Course ◽  
And Performance ◽  
Falling Weight

Pavement surface deflection has been used by researchers and highway agencies to assess the structural condition of the pavement structure. None of the currently available approaches provides an acceptable evaluation method for the rigid pavement structural capacity at the network level. In this research, pavement structural ratio (PSR) and overall pavement structural index (OPSI) were derived from deflection bowls generated from finite element simulations and validated by actual field deflection data measured by falling weight deflectometer and performance data extracted from long-term pavement performance database. The PSR parameter provides structural evaluation of the rigid pavement slab and the base course above the subgrade only. Whereas, OPSI parameter provides an overall evaluation of the pavement structure and the subgrade.

Falling Weight Deflectometer Correlation

2005 ◽  
Vol 1905 (1) ◽  
pp. 90-96 ◽  
Author(s):  
Sameh Zaghloul ◽  
Zubair Ahmed ◽  
D. J. Swan ◽  
Andris A. Jumikis ◽  
Nick Vitillo
Keyword(s):  
New Jersey ◽  
Prediction Models ◽  
Pavement Management ◽  
Atlantic City ◽  
Falling Weight Deflectometer ◽  
Remaining Service Life ◽  
Structural Capacity ◽  
Pavement Management Systems ◽  
Rehabilitation Needs ◽  
Falling Weight

The falling weight deflectometer (FWD) is commonly used to perform project-and network-level structural evaluations. Some highway agencies perform network-level FWD testing as a part of their pavement management systems to assess in situ structural capacity, remaining service life, and current rehabilitation needs. Through prediction models, future condition and needs are also estimated. In contrast, project-level FWD testing is typically performed as part of the rehabilitation design process. Calibrated FWD equipment provides repeatable data for a pavement section (i.e., data obtained with the same unit, at the same location, and under similar conditions). However, different FWD devices manufactured by the same or different manufacturers do not necessarily provide similar deflection basins when they test the same section, even if they are calibrated. This paper summarizes the results of a study performed for the New Jersey Department of Transportation to assess the differences among the FWD devices available in New Jersey and to correlate the results obtained with the different devices. Two rounds of testing were performed on flexible and rigid pavement sections located in the FAA William J. Hughes Technical Center in Atlantic City. The first testing cycle was performed in November 2002, and the second was performed in May 2004. The analysis results indicate that significant differences in repeatability and reproducibility may exist between different FWD devices.

Network Pavement Evaluation with Falling-Weight Deflectometer and Ground-Penetrating Radar

2003 ◽  
Vol 1860 (1) ◽  
pp. 90-99 ◽  
Author(s):  
A. Samy Noureldin ◽  
Karen Zhu ◽  
Shuo Li ◽  
Dwayne Harris
Keyword(s):  
Data Collection ◽  
Ground Penetrating Radar ◽  
Pavement Management ◽  
Falling Weight Deflectometer ◽  
Pavement Condition ◽  
Condition Rating ◽  
Structural Capacity ◽  
Pavement Evaluation ◽  
Ground Penetrating ◽  
Falling Weight

Nondestructive testing has become an integral part of pavement evaluation and rehabilitation strategies in recent years. Pavement evaluation employing the falling-weight deflectometer (FWD) and ground-penetrating radar (GPR) can provide valuable information about pavement performance characteristics and be a very useful tool for project prioritization purposes and estimation of a construction budget at the network level. Traditional obstacles to the use of the FWD and GPR in pavement evaluation at the network level used to be expenses involved in data collection, limited resources, and lack of simplified analysis procedures. Indiana experience in pavement evaluation with the FWD and the GPR at the network level is presented. A network-level FWD and GPR testing program was implemented as a part of a study to overcome those traditional obstacles. Periodic generation of necessary data will be useful in determining how best to quantify structural capacity and estimate annual construction budgets. Three FWD tests per mile on 2,200 lane-mi of the network is recommended annually for network-level pavement evaluation. The information collected will allow the equivalent of 100% coverage of the whole network in 5 years. GPR data are recommended to be collected once every 5 years (if another thickness inventory is needed) after the successful network thickness inventory conducted in this study. GPR data collection is also recommended at the project level and for special projects. Both FWD and GPR data are recommended to be used as part of the pavement management system, together with automated collection of data such as international roughness index, pavement condition rating, rut depth, pavement quality index, and skid resistance.

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