Light-weight deflectometer for mechanistic quality control of base course materials

The light-weight deflectometer presents significant potential for compaction quality control and for determining in situ resilient modulus of pavement layers during construction. Data collected from a laboratory large-scale model experiment and two light-weight deflectometer devices (Keros and Zorn) were used to develop a means of estimating the resilient modulus of various base course materials. The procedure can be used for validating the input parameters in design. Measured surface elastic deflections of a layered pavement system from the LWD devices must be corrected for the effect of subgrade deflection and the differences in the state of stresses. A power function represents the relationship between the corrected elastic deflection from the light-weight deflectometers and the resilient modulus of the base course layer from the large-scale model experiment. This study provides a basis for use of the light-weight deflectometer in estimating as-constructed resilient modulus of a base course layer involving natural and recycled unbound materials as well as fly ash stabilised materials.