Assessment of Consumer-Grade 3D Scanning Technologies for Aggregate Stockpile Volume Estimation in Pavement Construction

Abstract: Accurate volume measurement of aggregate stockpiles is critical for material inventory control and cost management in pavement construction. Traditional manual methods are unreliable, and while terrestrial laser scanning (TLS) provides high precision, its cost and complexity limit routine field use. This study evaluates the accuracy of three measurement technologies—professional-grade TLS (FARO Focus Premium), smartphone photogrammetry (iPhone 15 Pro Max), and iPhone LiDAR (3D Scanner app)—for measuring volumes of loose aggregate piles with known reference volumes. Three materials commonly used in pavement applications were tested: open-graded gravel (S1), silty sand type A (S2), and silty sand type B (S3), with moisture contents ranging from 1.87% to 18.68% and varying surface textures and colors. Reference volumes of 0.0566 m³ were established using the ASTM C29 unit box method. Point clouds were processed using FARO Scene, Agisoft Metashape, and CloudCompare for registration and volume estimation. TLS provided the most accurate measurements with relative errors of 4.24% to 9.54%. Smartphone photogrammetry moderately overestimated volumes (11.31% to 14.84%) but performed consistently across material types. iPhone LiDAR exhibited the highest variability with errors up to 21.91%, particularly for darker, moisture-saturated materials. All methods showed increasing error with finer-grained, wetter materials. These findings demonstrate that while TLS remains optimal for high-precision applications, smartphone photogrammetry offers a practical, cost-effective alternative for pavement construction contractors conducting routine stockpile measurements where consistency and field accessibility are prioritized over sub-centimeter accuracy.