Comparison of 2-D and 3-D shape analysis of concrete aggregate fines from VSI crushing

• Published in: Powder technology Vol. 309; pp. 110 - 125
• Main Authors: Cepuritis, Rolands, Garboczi, Edward J., Jacobsen, Stefan, Snyder, Kenneth A.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01-03-2017; Elsevier BV
• Subjects: 3-D technology; Aggregates; Analysis; Computed tomography; Concrete; Crushed aggregate fines; Crushing; Dynamic image analysis; Flocculation; Image analysis; Image processing; Particle size; Quality control; Quarries; Shape; Spherical harmonics; Tomography; Two dimensional analysis; Vertical shaft impact crusher; X ray microtomography; X-ray computed tomography; X-rays; Vertical shaft impact crusher; Shape; Dynamic image analysis; X-ray computed tomography; Crushed aggregate fines
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/j.powtec.2016.12.037

The shape of concrete aggregate fine particles (fines), with particle sizes between 3μm and 250μm, produced by high-speed vertical shaft impact (VSI) crushing of 10 different rock types from quarries in Norway, has been studied by both dynamic image analysis (DIA), which is a two-dimensional (2-D) method, and X-ray computed microtomography (μCT) coupled with spherical harmonic (SH) analysis, which is a three-dimensional (3-D) method. The 3-D μCT results serve as a check on the 2-D DIA results. The intent was to evaluate the applicability of the 2-D DIA method to extract shape parameters that could represent the actual 3-D shape of the VSI crushed concrete aggregate particles. The results show that the 2-D DIA method has problems correctly measuring the shape of particles smaller than about 40μm due to too large of a pixel size and possibly some particle flocculation. The findings of this paper show, however, that if a large enough number of particles are analysed by the 2-D DIA method, a good but limited indication of the actual 3-D shape of the irregular crushed aggregate fines larger than 40μm can be acquired and used for simple quality control in hard rock quarries.
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•The 2-D DIA method is unable to measure shape of particles smaller than 40μm.•Main limitation of the 2-D DIA method is the pixel size and particle flocculation.•The 2-D DIA method shows satisfying results for particles larger than 40μm.•The 2-D DIA method is applicable for simple quality control at hard rock quarries.