Abstract：In the numerical simulation of specimen of concretes in meso-level, to reduce the repellency and distances between aggregates as well as to improve the content of the aggregates and the computational speed of generating the specimen, the method of establishing a three-dimensional parametric aggregates model is developed. This method makes use of the parametric equation of the aggregates, presents a rule to determine whether a spatial point is inside the aggregates. Moreover, the fast algorithm for computing the distance between the spatial points and the generated aggregates is presented and the corresponding error analysis is given. Based on these facts, the space between aggregates can be controlled and therefore, the content of aggregates in the specimen can be improved. Numerical results show that this is an effective method, with which the concrete specimen with more than 55% irregular aggregates in volume can be generated according to two gradation. This is very close to content of aggregates in practical concrete. Therefore, an aggregate model of concretes in meso-level for further mechanical analysis is developed.
2015, Vol. 36 
