trb lwd 07.pdf (651.67 kB)
Review of lightweight deflectometer for routine in situ assessment of pavement material stiffness
journal contribution
posted on 2008-08-01, 14:17 authored by Paul FlemingPaul Fleming, Matthew FrostMatthew Frost, John Peter LambertThe 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 SciencesPublication date
2007Notes
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
0361-1981Language
- en