Influence of aggregate size and volume fraction on 1 shrinkage induced micro - cracking of concrete and 2 mortar

9 In this paper, the influence of aggregate size and volume fraction on shrinkage induced micro-cracking and 10 permeability of concrete and mortar was investigated. Nonlinear finite element analyses of model concrete 11 and mortar specimens with regular and random aggregate arrangements were performed. The aggregate 12 diameter was varied between 2 and 16 mm. Furthermore, a range of volume fractions between 0.1 and 13 0.5 was studied. The nonlinear analyses were based on a 2D lattice approach in which aggregates were 14 simplified as monosized cylindrical inclusions. The analysis results were interpreted by means of crack 15 length, crack width and change of permeability. The results show that increasing aggregate diameter 16 (at equal volume fraction) and decreasing volume fraction (at equal aggregate diameter), increases crack 17 width and consequently greatly increases permeability. 18