Effect of aggregate sphericity on the mechanical properties of ERCC based on highly detailed simulation

Electrically conductive roller-compacted concrete (ERCC) is a novel functional construction material with self-heating ability, which can be applied to solve problems of low efficiency of crushed snow removal and deicing on expressway and airport runway, and difficult temperature control of dam structures. Natural aggregates with high sphericity and crushed aggregates with low sphericity are the sources of ERCC construction. However, the impact of aggregate sphericity on ERCC is currently unclear. This study performed the macro and micro experiments of the core samples from a large-scale ERCC specimen with rolling construction technology. Based on the experimental results, the mechanical properties of ERCC with different aggregate sphericities are analyzed with the highly detailed simulation method by coupling continuous medium method and discontinuous medium method. The results show that increased sphericity of the aggregate can lead to a decrease in the number of aggregates generated, and the simplified spherical model adopted in the traditional mesoscale simulation method will underestimate the strength of concrete. Furthermore, When the sphericity of aggregate is 0.645, the compressive strength and splitting tensile strength of ERCC are increased by 25.34% and 35.04% compared with that of spherical aggregate respectively. In engineering, the crushed aggregate is suggested for rolling construction of ERCC. The results are in accordance with the statistical laws of the field statistical data in engineering practice.(c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).