Concrete meso-structure characteristics and mechanical property research with numerical methods.

Concrete meso-structure significantly affects its mechanical property, as crack generally starts and develops basically along the interface between aggregate and mortar on the meso-scale. The cracking path is highly dependent on the interface structure, the main component of concrete meso-structure. Since the interface is formed due to aggregate distributing in mortar mix, the relation between aggregate surface area and interface perimeter could be considered as a representative index of concrete meso-structure. As it is too complicated to adopt traditional methods to represent this relation, in order to better understanding the influence of meso-structure change on mechanical property, fractal theory is introduced to explore the relationship, with the main focus on the characteristics of the concrete meso-structure and its influence on mechanical property. Results show that the specimen size has great impact on meso-structure and mechanical property, while the influence of aggregate volume fraction can be neglected. It is more obvious in larger specimen size that aggregate volume fraction increase could contribute a lot to bearing capacity improving and whole stress level descending. Besides, aggregate volume fraction increase could improve the local cracking stress, but reduce the cracking strain, resulting in cracking brittleness. [ABSTRACT FROM AUTHOR]