通过本文进行的大试件、大骨料水工混凝土梁三点弯曲断裂试验研究表明:混凝土的断裂韧度K_(IC)随试件尺寸的增大而增大,当试件高度由10cm增至70cm时,K_(IC)增加了61％。其次,K_(IC)随骨料粒径D_(max)变化而变化。当D_(max)≤40mm时,K_(IC)随D_(max)增大而增大;当D_(max)=40-150mm时,K_(IC)随D_(max)增大而减小。 Through the three-point bending test of the large concrete specimen and large aggregate hydraulic concrete beam, the fracture toughness K_(IC) of concrete increases with the increase of the size of the specimen, and the height of the specimen increases from 10cm. Up to 70cm, K_(IC) increased by 61%. Second, K_(IC) changes with the change of the aggregate particle size D_(max). When D_(max)≤40mm, K_(IC) increases with D_(max); when D_(max)=40-150mm, K_(IC) decreases with D_(max).