Shi Chenglin, Zhao Ruize, Wang Wensheng
College of Transportation Science and Engineering, Jilin Jianzhu University, Changchun 130118, China.
Kay Laboratory of Architectural Cold Climate Energy Management, Ministry of Education, Changchun 130118, China.
Materials (Basel). 2023 Oct 20;16(20):6793. doi: 10.3390/ma16206793.
Mud powders in aggregates are often found to cause deterioration of concrete properties. Based on a study of the mechanical properties of bridge deck leveling concrete (BDLC) containing different mud powders at various ages, the effects of mud powders on concrete durability were evaluated through rapid chloride permeability testing, freeze-thaw testing, and the coupling of salt solution and a freeze-thaw test. The properties of the interfacial transition zone (ITZ) were also investigated via microhardness testing. The test results showed that mud powder reduced the compressive strength, static compressive elastic modulus, and bond strength at early stages of curing. Moreover, mud powder was found to reduce the tensile properties and durability of concrete, with clay powder causing a greater reduction than mud powder in river sands and coarse aggregate. In addition, the width of the ITZ of concrete containing mud powder was found to increase by 23.1-48.3%. A significant correlation between the ITZ and the tensile properties, as well as the durability of concrete, was also observed. Therefore, in order to improve the tensile properties and durability of BDLC in seasonally frozen regions, the content of mud powder in the aggregates should be minimized according to the different compositions of mud powders. The coupling effect of salt solution and a freeze-thaw cycle should also be taken into consideration.
通常发现骨料中的泥粉会导致混凝土性能劣化。基于对不同龄期含有不同泥粉的桥面板找平混凝土（BDLC）力学性能的研究，通过快速氯离子渗透性试验、冻融试验以及盐溶液与冻融试验的耦合，评估了泥粉对混凝土耐久性的影响。还通过显微硬度测试研究了界面过渡区（ITZ）的性能。试验结果表明，泥粉在养护早期降低了抗压强度、静态抗压弹性模量和粘结强度。此外，发现泥粉会降低混凝土的拉伸性能和耐久性，其中粘土粉导致的降低比河砂和粗骨料中的泥粉更大。另外，发现含有泥粉的混凝土的ITZ宽度增加了23.1 - 48.3%。还观察到ITZ与混凝土的拉伸性能以及耐久性之间存在显著相关性。因此，为了提高季节性冰冻地区BDLC的拉伸性能和耐久性，应根据泥粉的不同成分将骨料中泥粉的含量降至最低。还应考虑盐溶液与冻融循环的耦合作用。
