Abstract:
The success of any pavement construction project depends on using durable materials as well as
following proper construction practices. Durability of the pavement depends on selecting proper
materials to meet design material properties and constructing pavement layers to achieve design
strength properties. Pavement layer strength generally measured using deformation characteristics in
terms of elastic modulus or resilient modulus values. Both AASHTO 1993 empirical pavement design
guide and the new mechanistic pavement design guide use subgrade soil resilient modulus as a primary
design parameter. However, during pavement construction subgrade and base construction quality
measurements are routinely measured in terms of field density and moisture content. This is the
accepted method for most of the highway agencies in the world. The main reason for this practice is the
long history and experience of using density/moisture measurements for compaction control and also
lack of proper field measuring equipments for modulus measurements.
Due to recent interest in mechanistic based pavement designs, an interest is gaining towards using
design parameters such as resilient or elastic modulus for construction quality control and acceptance.
Several highway agencies such as in United Kingdom and Germany extensively evaluated several
portable field devices for subgrade and base construction QA/QC. These devices include Light Weight
Deflectometer (LWD) GeoGauge and Dynamic Cone Penetrometer (DCP). In the USA, several states
have started evaluating these devices for pavement construction QA/QC.
This study is aimed at evaluating DCP and LWD as a pavement construction QA/QC tool. The objectives
of this study are (i) complete literature search for using stiffness measurements for pavement
construction quality evaluation (ii) determining the in-situ stiffness values based on DCP and LWD on
number of construction projects (iii) compare and contrast the stiffness measurements with density
and moisture content measurements.
This paper will include the literature search portion of the project and some preliminary results of
stiffness measurements and density/moisture content measurements on few construction projects.
