Hot mix asphalt (HMA) paving inspection covers plant operations, hauling, placement, and compaction. MDOT uses statistical acceptance with pay factors (PWL-based). Mix temperature at delivery: 275-325°F for standard PG binders. Lift thickness: maximum 3 inches compacted for surface course, 4 inches for base. Compaction: minimum 92% Gmm for surface, 91% for base. Nuclear density gauge or cores for verification. Joint density minimum 90% Gmm. Longitudinal joint offset minimum 6 inches from underlying joint.
References: AASHTO current edition, MI Standard Specifications, FHWA Technical Advisories, and applicable federal regulations (23 CFR). Contractors shall maintain current copies of all referenced standards on the project site.
Source: MDOT Construction Manual, 2024 Edition. Pages 13–14 of 29.