Automated measurement of aggregate properties: Part 2—flakiness index.

Autor: Bouquety, M., Descantes, Y., Barcelo, L., Larrard, F., Clavaud, B.
Zdroj: Materials & Structures; Jan2006, Vol. 39 Issue 1, p13-19, 7p
Abstrakt: Aggregate shape is considered to be a key parameter for concrete and bituminous mixtures design. Generally, this parameter is determined by calculating a ratio between the different dimensions of the particles and by comparing this ratio to a flatness or elongation limit. The standardized methods used for this purpose vary among countries, but all of them are slow and lack precision. In order to increase the rapidity and accuracy of aggregate shape determination, a model based on a two-dimensional image analysis approach has been developed and implemented in the French VDG 40 videograder, to determine the flakiness index referenced to in European standard EN 933-3. The parameters of the model have been determined from an extensive experimental database, involving manual shape characterization of 122 samples, each of one containing about 500 particles. The predictive performance of the model has been assessed through supplementary data (including materials from other quarries). A very good agreement between experimental and estimated flakiness indexes was found. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index