caa a22 4500 475813529 CHVBK 20180406123803.0 cr unu---uuuuu 170329e20000401xx s 000 0 eng 10.1007/PL00001103 doi (NATIONALLICENCE)springer-10.1007/PL00001103 Hecht C. A. Martin-Luther-Universität, Halle-Wittenberg, Institut für Geologische Wissenschaften und Geiseltalmuseum, Domstraße 5, 06108 Halle-Saale, Germany, e-mail: hecht@geologie.uni-halle.de, DE aut Appolonian Packing and Fractal Shape of Grains Improving Geomechanical Properties in Engineering Geology [Elektronische Daten] [C. A. Hecht] —Fractal packing and highly irregular shaped particles increase the mechanical properties of rocks and building materials. This suggests that fractal methods are good tools for modeling particle mixes with efficient properties like maximum strength and maximum surface area or minimum porosity and minimum permeability. However gradings and packings are calculated by "Euclidean” disk models and sphere models. Surprisingly even the simplest models are far more complex than they appear. The fractal "Appolonian packing model” is proposed as the most universal two-dimensional packing model. However the inhomogeneity of gradings and the irregularity of natural grain shapes and surfaces are not reflected by these models. Consequently calculations are often far from empirical observations and experimental results. A thorough quantification of packings and gradings is important for many reasons and still a matter of intense investigation and controversial discussion. This study concentrates on fractal models for densely packed non-cohesive rocks, crushed mineral assemblages, concrete and asphalt mixtures. A summary of fractal grain size distributions with linear cumulative curves on log-log plots is presented for these mixtures. It is shown that fractal two-dimensional and three-dimensional models for dense packings reflect different physical processes of material mixing or geological deposition. The results from shear-box experiments on materials with distinct grain size distributions show a remarkable increase of the mechanical strength from non-fractal to fractal mixtures. It is suggested that fractal techniques need more systematical application and correlation with results from material testing experiments in engineering geology. The purpose of future work should lead towards the computability of dense packings of angular particles in three dimensions. Birkhäuser Verlag Basel,, 2000 Key Words: Appolonian, packing, fractal, engineering, geology nationallicence https://doi.org/10.1007/PL00001103 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/PL00001103 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Hecht C. A. Martin-Luther-Universität, Halle-Wittenberg, Institut für Geologische Wissenschaften und Geiseltalmuseum, Domstraße 5, 06108 Halle-Saale, Germany, e-mail: hecht@geologie.uni-halle.de, DE aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer