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Review of lightweight deflectometer for routine in situ assessment of pavement material stiffness

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journal contribution
posted on 01.08.2008, 14:17 by Paul Fleming, Matthew Frost, John Peter Lambert
The use of a portable lightweight deflectometer (LWD) for construction quality control or material investigation for earthworks and road construction is increasing around the world. This paper reviews the LWD as a field evaluation tool, discusses the test variables and data quality and concludes both on its usefulness and also its limitations for a variety of earthwork and road assessment scenarios. The paper aims to provide a state of the art reference document for LWD users, consultants, material specifiers, contractors and clients. It reviews data from road foundations (subgrades, granular capping and sub-base) and fully constructed in-service (thinly surfaced) roads, to demonstrate the flexibility of the LWD but also show that its determination of ‘stiffness modulus’ may differ from that of the conventional Falling Weight Deflectometer (FWD) to a varying extent. A series of laboratory investigations are presented that demonstrate the sensitivity to uniformity of plate/surface contact, and also limitations in the interpretation of peak displacement from the device. In conclusion, a good understanding of the device workings and careful specification of the test variables are required to both analyse the data correctly and permit comparison between data sets. The device is concluded to be a useful and versatile field quality control and pavement investigation tool, if an understanding of the device issues is considered by data users.

History

School

  • Architecture, Building and Civil Engineering

Citation

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 : Journal of the Transportation Research Board, 2004, pp. 80-87 [DOI:10.3141/2004-09]

Publisher

© National Academy of Sciences

Publication date

2007

Notes

This is a journal article. It was published in the journal, Transportation Research Record : Journal of the Transportation Research Board, [© National Academy of Sciences] and the definitive version is available at: http://trb.metapress.com/content/120399/

ISSN

0361-1981

Language

en

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Keywords

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