Influence of particle size distribution, test time, and moisture content on sandy stratum LCPC abrasivity test results

This paper focuses on the influence of particle size distribution, test time, and moisture content on the Laboratoire Central des Ponts et Chaussées (LCPC) abrasivity coefficient (LAC). Image analysis and X-ray diffraction were used to analyze the particle shape characteristics and equivalent quartz content (EQC) of a sandy stratum. The test results show no significant differences in the shape characteristics and EQC of particles with different diameters obtained from the same sandy stratum. For the same EQC, the main factors affecting the LAC are particle size distribution, test time, and moisture content. An optimized effective size (ES_op) index was established to represent different particle size distributions. The test results showed that the ES_op index is more accurate than other indices in determining the LAC of soil samples, and the LAC had a linear relationship with the ES_op index. Soil samples with moisture content less than the saturated moisture content have an LAC larger than that of a dry soil sample, and soil samples with moisture content greater than the saturated moisture content have an LAC similar to that of a dry soil sample. The influence of test time on the LAC of the soil samples could be divided into two stages, where the first and second stages are represented by a quadratic function and a linear function, respectively.