Capturing a Layer Response during the Curing of Stabilized Earthwork Using a Multiple Sensor Lightweight Deflectometer
Publication: Journal of Materials in Civil Engineering
Volume 27, Issue 6
Abstract
The lightweight deflectometer (LWD) is a portable device that measures surface deflections and applied force, from which dynamic stiffness and elastic modulus can be estimated. The inclusion of radial offset sensors with LWD testing, referred to here as multiple sensor LWD testing, stemmed from the well-established falling weight deflectometer (FWD) testing method. However, little research exists in the literature addressing LWD use on stabilized or lightly bound layers with multiple sensors, or exploring the applicability of backcalculating/isolating layer moduli from multiple sensor LWD tests. To this end, over 200 multiple sensor LWD tests on stabilized base materials were performed at five sites and rigorously analyzed to determine if the test could capture growth in stabilized base stiffness while the underlying subgrade layer remained unchanged. Deflection results demonstrate that the LWD test is capable of detecting changes in the stiffness of the stabilized base material during curing as illustrated by the decreasing magnitude in center deflections. Furthermore, radial offset deflections measuring 60 cm from the plate center remained constant during curing, providing valuable information about the subgrade support. The findings made directly from the deflections were confirmed via an analytical backcalculation using Boussinesq’s equations and Odemark’s method of equivalent thickness. The use of multiple sensor LWD testing allows for a richer interpretation of earthwork behavior than the traditional center deflection LWD results.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors would like to acknowledge the Federal Highway Administration and the Central Federal Lands Division for the technical and financial support of this study, and David Stamp for his contributions to the study.
References
AASHTO. (1993). AASHTO guide for design of pavement structures, Vol. 1, Washington, DC.
Adam, C., Adam, D., and Kopf, F. (2009). “Computational validation of static and dynamic plate load testing.” Acta Geotechnica, 4(1), 35–55.
Ahmed, A. T., and Khalid, H. A. (2011). “Back-calculation models to evaluate the LFWD moduli of a road foundation layer made with bottom ash waste.” Transportation Research Board, Annual Meeting, (CD ROM), Transportation Research Board, Washington, DC.
Beyer, M., Camargo, F., Davich, P., and O’Neal, C. (2007). Lightweight deflectometer (LWD) user’s guide, Minnesota Dept. of Transportation, Office of Materials, Maplewood, MN.
Boussinesq, J. (1885). Applications des Potentiels à l’Étude de l’Équilibre et du Mouvement des Solides Élastiques, Gauthier-Villars, Paris.
Burmister, D. M. (1945). “The general theory of stresses and displacements in layered systems. I.” J. Appl. Phys., 16(2), 89–94.
Chatti, K., Ji, Y., and Harichandran, R. (2004). “Dynamic time domain backcalculation of layer moduli, damping, and thickness in flexible pavements.” Transportation Research Record 1869, Transportation Research Board, Washington, DC, 106–116.
Davich, P., Camargo, F., Larsen, B., Roberson, R., and Siekmeier, J. (2006). “Validation of DCP and LWD moisture specifications for granular materials.”, Minnesota Dept. of Transportation, Saint Paul, MN.
El-Badaway, S. M., and Kamel, M. A. (2011). “Assessment and improvement of the accuracy of the Odemark transformation method.” Int. J. Adv. Eng. Sci. Technol., 5(2), 105–110.
Fleming, P. R., Frost, M. W., and Lambert, J. P. (2007). “Review of lightweight deflectometer for routine in situ assessment of pavement material stiffness.” Transportation Research Record 2004, Transportation Research Board, Washington, DC, 80–87.
Fleming, P. R., Frost, M. W., and Lambert, J. P. (2009). “Lightweight deflectometers for quality assurance in road construction.” Bearing capacity of roads, railways and airfields: Proc., 8th Int. Conf. (BCR2A’09), June 29–July 2 2009, E. Tutumluer and I. L. Al-Qadi, eds., Univ. of Illinois at Urbana–Champaign, Champaign, IL.
Fleming, P. R., Lambert, J. P., Frost, M. W., and Rogers, C. (2002). “In situ assessment of stiffness modulus for highway foundations during construction.” Proc., 9th Int. Conf. on Asphalt Pavements, International Society for Asphalt Pavements, Lino Lakes, MN.
Grasmick, J. G. (2013). “Using the light weight deflectometer with radial offset sensors on two-layer systems for construction quality control/quality assurance of reclaimed and stabilized materials.” M.S. thesis, Colorado School of Mines, Golden, CO.
Hildebrand, G. (2003). “Comparison of various types of bearing capacity equipment.” Nordic Road Transp. Res., 3, 12–14.
Horak, E., Maina, D., and Guiamba, D. (2008). “Correlation study with the lightweight deflectometer in South Africa.” 27th Southern African Transport Conf., Lydiana Pretoria, South Africa, 304–312.
Hossain, M. S., and Apeagyei, A. K. (2010). “Evaluation of the lightweight deflectometer for in situ determination of pavement layer moduli.”, Virginia Transportation Research Council, Charlottesville, VA.
Khosravifar, S., Schwartz, C., and Goulias, D. (2013). “Time-dependent stiffness increase of foamed asphalt stabilized base material.” Proc., 9th Int. Conf. on Bearing Capacity of Roads, Railways, and Airfields, CRC Press, Boca Raton, FL.
Lin, D., Liau, C., and Lin, J. (2006). “Factors affecting portable falling weight deflectometer measurements.” J. Geotech. Geoenviron. Eng., 804–808.
Loizos, A., and Boukovalas, G. (2005). “Pavement soil characterization using a dynamic stiffness model.” Int. J. Pavement Eng., 6(1), 5–15.
Mooney, M. A., and Miller, P. K. (2009). “Analysis of lightweight deflectometer test based on in situ stress and strain response.” J. Geotech. Geoenviron. Eng., 199–208.
Mooney, M. A., Nocks, C. V., Seldon, K. L., Bee, G. T., and Senseney, C. T. (2008). Improving quality assurance of MSE wall and bridge approach earthwork compaction, Colorado Dept. of Transportation, Denver.
Nazzal, M. D., Abu-Farsakh, M. Y., and Alshibli, K. (2007). “Evaluating the deflectometer light falling weight device for in situ measurement of elastic modulus of pavement layers.” Transportation Research Record 2016, Transportation Research Board, Washington, DC, 13–22.
Roberson, R. (2007). “Influence of material properties and drainage practices on pavement base and subgrade water content and stiffness.” M.S. thesis, Soil Science, Univ. of Minnesota, Minneapolis.
Schmalzer, P. N., Rada, G. R., and Miller, J. S. (2007). “Falling weight deflectometer (FWD) testing and analysis guidelines volume I.”, Federal Highway Administration, Federal Lands Highway Division, Washington, DC.
Senseney, C. T., Krahenbuhl, R. A., and Mooney, M. A. (2013). “Genetic algorithm to optimize layer parameters in lightweight deflectometer backcalculation.” Int. J. Geomech., 473–476.
Senseney, C. T., and Mooney, M. A. (2010). “Characterization of a two-layer soil system using a lightweight deflectometer with radial sensors.” Transportation Research Record 2186, Transportation Research Board, Washington, DC, 21–28.
Siekmeier, J., et al. (2009). “Using the dynamic cone penetrometer and lightweight deflectometer for construction quality assurance.”, Minnesota Dept. of Transportation, St. Paul, MN.
Stamp, D. H., and Mooney, M. A. (2013). “Influence of lightweight deflectometer characteristics on deflection measurement.” Geotech. Test. J., 36(2), 216–226.
Ullidtz, P. (1998). Modelling flexible pavement response and performance, Polyteknisk Forlag, Lyngby, Denmark.
Ullidtz, P., and Peattie, K. R. (1980). “Pavement analysis by programmable calculators.” J. Transp. Eng., 106(5), 581–597.
Vennapusa, P. R., and White, D. J. (2009). “Comparison of lightweight deflectometer measurements for pavement foundation materials.” Geotech. Test. J., 32(3), 239–251.
Zhang, W., and Macdonald, R. A. (1999). “Pavement subgrade performance study in the danish road testing machine, paper No. GS2-2.” Proc. 1999 Int. Conf. on Accelerated Pavement Testing (CD-ROM), Transportation Research Board, Washington, DC.
Information & Authors
Information
Published In
Journal of Materials in Civil Engineering
Volume 27 • Issue 6 • June 2015
Copyright
© 2014 American Society of Civil Engineers.
History
Received: Feb 6, 2014
Accepted: May 29, 2014
Published online: Aug 13, 2014
Discussion open until: Jan 13, 2015
Published in print: Jun 1, 2015
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.