CCIL - Canadian Council of Independent Laboratories Pavement Construction and Inspection Questions and Answers Flashcards

What is the primary purpose of tack coat applied between asphalt pavement layers?

Answer: To bond successive asphalt lifts together to prevent slippage

Tack coat (typically SS-1h or CSS-1h emulsion) creates an adhesive bond between existing and new asphalt layers, preventing horizontal slippage under traffic loads.

What AASHTO standard test method governs measuring ride quality of pavement using a profilograph or inertial profiler?

Answer: AASHTO R 57 / ASTM E950

AASHTO R 57 (referencing ASTM E950 for Class 1 profilers) covers the standard practice for operation of inertial profilers to measure longitudinal pavement profile and IRI.

What is the purpose of conducting a field core extraction from a compacted asphalt pavement after placement?

Answer: To verify in-place density, thickness, and extract samples for air void and VMA determination

Field cores are extracted to verify compacted density and lift thickness compliance, and laboratory analysis of cores determines air voids and voids in the mineral aggregate (VMA).

During granular base compaction inspection, what test is commonly used to verify in-place density of crushed stone base materials?

Answer: Sand cone test (ASTM D1556)

The sand cone method (ASTM D1556) measures the in-place density of granular materials by filling an excavated hole with calibrated Ottawa sand to determine the volume of material removed.

What does the term 'mat temperature uniformity' refer to during asphalt paving inspection?

Answer: Consistent surface temperature across the full width of the freshly placed mat behind the paver screed

Mat temperature uniformity refers to avoiding cold streaks or thermal segregation across the mat width, which causes differential compaction and premature cracking.

What is the primary indicator of rutting susceptibility in a dense-graded hot mix asphalt mix design?

Answer: High binder content with insufficient VMA relative to aggregate structure

Rutting is most often caused by excess asphalt binder filling void space in the aggregate skeleton, reducing the load-carrying capacity through shear deformation of the binder.