Using accurate information regarding the thickness can allow for accurate volume calculations needed for the repair or renewal.
Any modification to, or general wear and tear of a given pavement or sidewalk surface can result in the requirement for replacement of the existing asphalt.
A new bus stop project on an existing road in Vancouver required accurate asphalt thickness measurement in order to avoid unnecessary replacement of the existing pavement.
GeoScan used a high frequency GPR survey to achieve the required accuracy and a mid-range frequency GPR to reveal information about the structural details underpinning the area. Several grids with evenly spaced lines were laid out resulting an approximately 350 sqm of total coverage. The radar systems used were carefully calibrated onsite to ensure accurate depth measurements. Data was processed and compiled to produce contoured heatmap style results. Results were presented in a CAD workspace and digital reports delivered.
The GPR survey was complimented with Vuit 3D laser scanning to achieve accurate, scaled georeferencing of our survey grids, and a convenient way to view and present the asphalt thickness results.
The survey revealed a distinct change in the asphalt thickness due to the structural change to the subsurface that was confirmed with the survey results from the mid-range frequency GPR. The data uncovered not only the asphalt thickness but also the nature and location of the subsurface features such as: beams, voids and structural slab changes.