Use of Falling Weight Deflectometer and Dynamic Cone Penetrometer in Pavement Evaluation

1999 ◽  
Vol 1655 (1) ◽  
pp. 145-151 ◽  
Author(s):  
Jianzhou Chen ◽  
Mustaque Hossain ◽  
Todd M. Latorella
2019 ◽  
Vol 14 (1) ◽  
pp. 37-57
Author(s):  
Yang Zhang ◽  
Pavana Vennapusa ◽  
David Joshua White

There are plenty of in situ tests available to examine pavement foundation performance regarding stiffness and support conditions. This study evaluates several in situ tests of the stiffness and support conditions of concrete pavement foundation layers. The principal objective of this study was to evaluate the outputs from Dynamic Cone Penetrometer tests and Falling Weight Deflectometer tests. The California Bearing Ratio from Dynamic Cone Penetrometer tests and the deflection data from Falling Weight Deflectometer tests were correlated to the design parameter – modulus of subgrade reaction k through correlations employed in pavement design manuals. Three methods for obtaining the k values were conducted, with the intent to evaluate which method provides the results most similar to the target value and whether the studied correlations are reliable. The back-calculated k values from Falling Weight Deflectometer deflections and the weak layer California Bearing Ratio correlated k values based on the Portland Cement Association method were close to the target value, while the California Bearing Ratio empirically correlated k based on the American Association of State Highway and Transportation Officials method presented values significantly higher than the target value. Those previously reported correlations were likely to overestimate the k values based on subgrade California Bearing Ratio values.


Author(s):  
Moshe Livneh ◽  
Noam A. Livneh

The use of a new quality control (QC) and quality assurance (QA) specification involving Dynamic Cone Penetrometer (DCP) testing in concert with conventional moisture and density testing is becoming more and more frequent in various parts of the world. The need for this additional testing is essential, as the regular in-situ density tests cannot alone ensure the compliance of the layers constructed with the compaction requirements. Recent analyses of the correlation between the DCP testing and the California Bearing Ratio CBR testing show that QC and QA DCP testing is adequate to verify compaction, stability and vertical uniformity in both cohesive and granular soils. Two examples of DCP usage in two Israeli earthwork projects, one of clayey soils and the other of silty-sand soils, indicate the benefits of this usage along with, though for the clayey example only, Falling Weight Deflectometer (FWD) testing.


Author(s):  
Dallas N. Little

Lime-stabilized clay subgrades are used almost routinely in Texas to facilitate construction and to provide a foundation for aggregate base courses and hot mix surfaces. Research sponsored by the Texas Department of Transportation demonstrates that the in situ moduli and strength improvements afforded by lime stabilization of these layers are often significant and deserve structural consideration. A study of the range of modulus values determined from falling weight deflec-tometer deflection data and supported by in situ dynamic cone penetrometer data for 40 pavement subgrades indicates that the lime-stabilized subgrades provide a level of stiffness and strength that is similar to that of an unbounded aggregate base. This substantiates previous literature suggesting that properly designed and constructed lime-stabilized subgrades should be assigned AASHTO structural coefficients in the same range as unbound aggregate bases, that is, between 0.10 and 0.14.


Author(s):  
Murad Y. Abu-Farsakh ◽  
Munir D. Nazzal ◽  
Khalid Alshibli ◽  
Ekram Seyman

A comprehensive testing program was conducted to evaluate the potential use of the dynamic cone penetrometer (DCP) in the quality control–quality assurance procedure during the construction of pavement layers and embankments. The laboratory tests were conducted on different materials prepared inside two test boxes measuring 1.5 m x 0.9 m x 0.9 m (5 ft x 3 ft x 3 ft) located at the Louisiana Transportation Research Center (LTRC). The field tests were performed on different highway sections in Louisiana. In addition, nine test sections were constructed and tested at the pavement research facility site of the LTRC. In all laboratory and field tests, DCP tests were carried out in conjunction with the plate load test (PLT). Also, falling weight deflectometer (FWD) tests were carried out on the field sections. California bearing ratio (CBR) laboratory tests were performed on samples collected from the tested sections. Regression analysis was carried out on the collected data to correlate the DCP penetration rate with the three reference tests used in this study (PLT, FWD, and CBR). Further field tests were conducted to verify the developed regression models. The results showed that the developed models yielded good predictions of the measured FWD moduli and CBR values. This suggests that these models can be used reliably to evaluate the stiffness and strength of pavement materials.


2018 ◽  
Vol 2018 (6) ◽  
pp. 32-42
Author(s):  
Juliusz Sołkowski ◽  
Dawid Siemieński

This project is based on search for the method of measuring and evaluation the railway pavement construction. The authors note some analogies between road and railway, both in terms of construction and the dynamic load. Already in the 1960s a method for measuring road pavement deflections under dynamic load was developed using Falling Weight Deflectometer. During years the device and the results analysis method were developed and currently commonly used. The FWD device was adapted for use on railway pavement construction. The first tests were done in the field and have brought reliable results. The device and measuring and pavement evaluation methods are under development.


Author(s):  
A. Samy Noureldin ◽  
Karen Zhu ◽  
Shuo Li ◽  
Dwayne Harris

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.


Author(s):  
Douglas Steele ◽  
Hyung Suk Lee ◽  
Curt Beckemeyer ◽  
Thomas Van

Traffic speed deflection devices (TSDDs) have been developed since around 2000 to allow for safe and efficient structural evaluation of highway networks. One barrier to TSDD implementation is the inherent differences in deflections produced by moving truck loads and by falling weight deflectometer (FWD), the current deflection testing standard. To better understand the differences in data produced by the two devices, FHWA sponsored research into one particular TSDD, the rolling wheel deflectometer (RWD). The study utilized the finite layer program ViscoWave to model both FWD and RWD loads to demonstrate the effect of their inherent differences on pavement deflections and other simulated parameters. In addition, ViscoWave was used to generate theoretical FWD and RWD deflections for a diverse set of pavement structures and subgrade conditions. The resulting deflections were used to develop correlations between the two devices, which were validated with side-by-side FWD and RWD field tests performed on 23 sites. The research determined that the differences between FWD and RWD deflections vary depending on pavement factors and loading characteristics. The two devices produced similar deflections on thicker, stiffer, lower-deflection pavements, while the FWD produced relatively higher deflections on thinner, weaker, higher-deflection pavements. Therefore, use of common FWD data analysis programs will produce different results, such as layer moduli, for TSDD devices. Advanced analysis routines capable of modeling the TSDD’s moving load and loading configurations are needed.


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