Evaluation of the effect of slag properties on roadbed bearing capacity with X-ray CT
Hiromu Yano, Yusuke Kato, Seiji Hosohara, Kenta Miyazaki, Toshifumi Mukunoki
Abstract
The main application of steelmaking slag is base course material for road construction. In order to utilize slag as a base course material, it must possess the various characteristics specified in the relevant standard. Among these, the modified California Bearing Ratio (CBR) value, which evaluates performance as a base course material, is an important index in comparison with other competing materials. Although factors such as slag granularity and particle shape are expected to affect CBR characteristics and compaction properties, the particle properties and granularity of the steel slag differ depending on the refining processes in which the slag is formed. X-ray CT measurement of slag as base course material and the evaluation of effect of particle properties have not been examined until now. In this study, measurement of the internal phenomena of steelmaking slag as base course material by microfocus X-ray CT and various other measurements were carried out. This investigation revealed that the particle strength of porous particles was lower than that of dense particles regardless of the particle size, and the difference in base course bearing capacity was smaller than the difference in particle strength. Based on the mechanism by which stress propagates and an elastic finite element analysis were applied to the results obtained by X-ray CT, the stress distribution altered according to the change in the dispersion of the particle strength of each grain, and this affected the properties of the base course material, which is the integral value of the effective stress.