Mesoscale analysis of concrete under axial compression: Fid-Bau Portal

Mesoscale analysis of concrete under axial compression

Chen, Peng / Liu, Jinxi / Cui, Xiaomeng / Si, Shengpu

Highlights • A mesoscale model of concrete was developed based on the random distribution of aggregate. • The peak strain, elastic modulus and descending coefficient of the mortar were modified comparing with that of concrete. • The influences of aggregate content and ITZ property on the performance of concrete were analyzed. • The strength relationship between the mortar matrix and concrete was developed.

Abstract To relate the mesoscopic and macroscopic properties of concrete, a mesoscale model was developed in this paper based on the random distribution of coarse aggregate, in which the peak strain, elastic modulus, and the descending coefficient of mortar were modified compared with that of concrete. The modified model can make a better prediction on the mechanical behavior of concrete under axial compression, therefore it was used to conduct parameter analysis. The simulation results showed that the concrete cube’s peak stress and peak strain were more sensitive to the friction coefficient at the endplate than that of the concrete prism. Due to the compounded influence of coarse aggregate, the peak stress of concrete decreased first and then increased as the percentage of coarse aggregate varied from 10% to 45%. Both ITZ strength and mortar strength had a significant influence on the mechanical properties of concrete. Ultimately, the strength relationship between mortar matrix and concrete was developed when the ITZ fraction coefficient was set as 0.8.