为研究不同粗骨料最大粒径对水工混凝土的变形影响,探明国家标准规定的骨料粒级能否满足水工混凝土的要求,依托引江济淮工程,开展了粗骨料最大粒径为31.5 mm和40.0 mm的混凝土变形试验,探究2种骨料粒级混凝土长期耐久性能演变规律。结果表明:采用最大粒径31.5 mm骨料的混凝土极限拉伸值和弹性模量略大,动态疲劳性能较好;采用最大粒径40 mm骨料的混凝土干燥收缩以及自生体积变形小;2种不同骨料最大粒径的混凝土徐变度相当;采用最大粒径31.5 mm骨料的混凝土长期抗渗性和长期抗冻性均优于采用最大粒径40 mm骨料的混凝土。因此,最大粒径31.5 mm骨料应用于水工混凝土时,能满足水工混凝土性能要求且动态疲劳寿命及耐久性更优,但需要注意混凝土开裂问题。

The study aims to investigate the influence of maximum grain size of coarse aggregate on the deformation of hydraulic concrete, and assess whether the aggregate sizes specified by national standards meet the performance requirements for hydraulic concrete. Based on the Yangtze-Huaihe River Diversion Project, we conducted deformation tests on concrete with maximum coarse aggregate sizes of 31.5 mm and 40.0 mm and examined the evolution law of long-term durability performance of both aggregate sizes. Results indicate that concrete with a maximum aggregate size of 31.5 mm exhibits slightly higher ultimate tensile strength and modulus of elasticity, along with improved dynamic fatigue performance. In contrast, concrete with a maximum aggregate size of 40 mm shows reduced drying shrinkage and autogenous volumetric deformation, with comparable creep behavior to that of concrete with a 31.5 mm aggregate size. However, concrete with a 31.5 mm aggregate size demonstrates superior long-term impermeability and frost resistance compared to concrete with a 40 mm aggregate size. Therefore, using a maximum aggregate size of 31.5 mm in hydraulic concrete not only meets the performance requirements but also enhances dynamic fatigue life and durability. Nonetheless, attention should be given to potential concrete cracking issues.