scholarly journals Measurements of the elastic modulus of pavement subgrade layers using the SASW and FWD test methods

2015 ◽  
Vol 10 (2) ◽  
pp. 174-181 ◽  
Author(s):  
Nur Izzi Md. Yusoff ◽  
Sentot Hardwiyono ◽  
Norfarah Nadia Ismail ◽  
Mohd Raihan Taha ◽  
Sri Atmaja P. Rosyidi ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Elastic Modulus ◽  
Surface Wave ◽  
Time Lag ◽  
Test Methods ◽  
Pavement Management ◽  
Falling Weight Deflectometer ◽  
Surface Wave Propagation ◽  
Evaluation And Monitoring ◽  
Falling Weight

In pavement management systems, deflection basin tests, such as the Falling Weight Deflectometer test, are common techniques that are widely used, while the surface wave test, i.e. the Spectral Analysis of Surface Wave test, is recently employed as an alternative technique in pavement evaluation and monitoring. In this paper, the performance of both dynamic non-destructive tests on pavement subgrade investigation is presented. Surface wave propagation between a set of receivers was transformed into the frequency domain using the Fast Fourier Transform technique and subsequently a phase spectrum was produced to measure the time lag between receivers. Using the phase difference method, an experimental dispersion curve was generated. Inversion analysis based on the 3-D stiffness matrix method was then performed to produce a shear wave velocity profile. The elastic modulus of pavement layers was calculated based on linear elastic theory. In the Falling Weight Deflectometer test, seven geophones were used to collect in situ deflection data. Based on a back-calculation procedure with the ELMOD software, the elastic modulus of each flexible pavement layer can be obtained. Both techniques are able to comprehensively investigate the elastic modulus of the subgrade layer in existing pavement non-destructively. The elastic modulus between the Spectral Analysis of Surface Wave method and the Falling Weight Deflectometer test on the subgrade layer is observed to be in a good agreement. A correlation of the elastic modulus of thesubgrade layer from both techniques is also presented.

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.

scholarly journals Relationship between deformation moduli obtained using light falling weight deflectometer and static plate test on various types of soil

2014 ◽  
Vol 9 (4) ◽  
pp. 251-259 ◽  
Author(s):  
Karel Pospisil ◽  
Petr Zednik ◽  
Josef Stryk
Keyword(s):  
Test Methods ◽  
Falling Weight Deflectometer ◽  
Loading Test ◽  
Plate Test ◽  
Plate Loading Test ◽  
Static Modulus ◽  
Different Types ◽  
Falling Weight ◽  
The Relationship ◽  
Plate Loading

There is increasing effort to optimize test methods for evaluation of subgrade. It takes effect in aspiration in replacement of static plate loading test by other faster test methods. One of them is the use of Light Falling Weight Deflectometer. In many countries in Europe both static and dynamic plate tests are standardized. The presented paper introduces results of the research project dealing with the sensitivity of the relationship between static modulus and modulus obtained from the Light Falling Weight Deflectometer on specific types of soil. It is shown that there are significant differences in relationship between moduli values obtained using both methods on different types of soil.

scholarly journals A new method to determine maintenance and repair activities at network-level pavement management using falling weight deflectometer

2017 ◽  
Vol 23 (3) ◽  
pp. 338-346 ◽  
Author(s):  
Amir KAVUSSI ◽  
Mojtaba ABBASGHORBANI ◽  
Fereidoon MOGHADAS NEJAD ◽  
Armin BAMDAD ZIKSARI
Keyword(s):  
Resilient Modulus ◽  
Pavement Management ◽  
Falling Weight Deflectometer ◽  
Pavement Management System ◽  
Pavement Condition ◽  
Maintenance And Repair ◽  
Structural Evaluation ◽  
Data Collection And Analysis ◽  
Field Data Collection ◽  
Falling Weight

Pavement condition assessment at network level requires structural evaluation that can be achieved using Falling Weight Deflectometer (FWD). Upon analysing FWD data, appropriate maintenance and repair methods (preser­vation, rehabilitation or reconstruction) could be assigned to various pavement sections. In this study, Structural Condi­tion Index (SCI), defined as the ratio of Effective Structural Number (SNeff) to Required Structural Number (SNreq), was used to determine if a pavement requires preservation or rehabilitation works (i.e. preservation SCI > 1, rehabilitation SCI < 1). In addition to FWD deflection data, SCI calculation requires pavement layer thicknesses that is obtained using GPR with elaborated and time consuming works. In order to reduce field data collection and analysis time at network-level pavement management, SCI values were calculated without having knowledge of pavement layer thicknesses. Two regression models were developed based on several thousand FWD deflection data to calculate SNeff of pavements and resilient modulus (MR) of their subgrades. Subgrades MR values together with traffic data were then used to calculate SNreq. Statistical analysis of deflection data indicated that Area under Pavement Profile (AUPP) and the deflection at distance of 60 cm from load center (D60) parameters showed to have strong correlation with SNeff and MR respectively. The determination coefficients of the two developed models were greater than those of previous models reported in the literature. The significant result of this study was to calculate SNeff and MR using the same deflection data. Finally, imple­mentation of the developed method was described in determining appropriate Maintenance and Repair (M&R) method at network level pavement management system.

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.

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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