AASHTO R 91-18 PDF Download

AASHTO R 91-18 is a standard practice that provides guidelines for determining aggregate source shape values using digital image analysis shape properties. This standard focuses on assessing the shape characteristics of aggregates from a specific source or a blend of sources. The analysis utilizes digital image technology to measure and quantify the shape properties of the aggregates.

The standard outlines the procedures for conducting gradation analysis and shape property determination using digital image analysis. It provides detailed instructions on how to capture and process the digital images of the aggregates for accurate shape property analysis. The shape properties that are evaluated include parameters such as angularity, texture, elongation, and flatness.

By determining the shape values of aggregates, this standard aims to assess the suitability of the materials for specific construction applications. The shape characteristics of aggregates can impact their performance in various applications, such as concrete and asphalt mixtures. Therefore, this standard provides a systematic approach to evaluate and compare aggregate sources based on their shape properties, facilitating informed decisions in material selection and quality control.