Study on three-dimensional digital features of crushed stone aggregates in the self-compacting concrete filling layer

The inappropriate utilization of crushed stone aggregates could readily result in segregation of the selfcompacting concrete during the pouring process. In response to this challenge, this study analyzed the differences in three-dimensional digital features of aggregates used on-site. This study employed three-dimensional scanning method to measure the dimensions, volume, surface area, and point cloud coordinates of crushed stone and pebble aggregates. Morphological feature parameters of each aggregate, including sphericity, elongation, particle size dispersion, sphericity index, and fractal dimension, were calculated. Sphericity, sphericity index, and fractal dimension followed a normal distribution, while elongation and particle size dispersion adhered to a lognormal distribution. Linear fitting analysis revealed a strong correlation between sphericity and elongation, as well as sphericity and particle size dispersion, with correlation coefficients exceeding 0.99. However, correlations between sphericity and sphericity index, sphericity and fractal dimension, and fractal dimension and sphericity index were insignificant. For the distribution of morphology feature parameters, pebble aggregates often had 0 values for parameters like sphericity, closer to spherical, while crushed stone aggregates rarely had 0 values, suggesting elongated or flaky particle aggregates. The shape profile of the crushed stone aggregate was remodeled via the particle follow code simulation. The generated clump units relied on the linear parallel bond model to form the concrete structure. Through qualitative analysis, the removal of these particles revealed the presence of disconnected units containing internal voids, thereby posing a risk of segregation. This study provided valuable insights into offering practical guidance for aggregate selection on construction sites.