| 摘要: |
| 试验主要研究了粉煤灰与矿渣粉掺量以及新拌混凝土含气量对混凝土在硫酸盐和干湿循环耦合作用下质量损失、抗压强度、相对动弹性模量等性能变化的影响。研究结果表明：经过3个干湿循环周期后，掺有矿物掺合料的混凝土试件强度增长大于基准组混凝土；从第4个干湿循环周期开始，掺矿物掺合料的混凝土试件的质量损失均小于基准组混凝土，且试件质量损失大大减少；掺加矿渣后，混凝土试件经过6次干湿循环周期，相对动弹性模量仍保持在60%以上；粉煤灰和矿粉复掺对混凝土的抗硫酸盐干湿循环破坏能力有所提高，当粉煤灰与矿粉比例为3∶1时，采用复掺对改善干湿循环过程中混凝土试件的抗压强度的效果最好。并且，混凝土中适当引气也可提高其抗硫酸盐干湿循环性能。 |
| 关键词: 硫酸盐 干湿循环 耦合作用 矿物掺合料 混凝土耐久性 动弹性模量 |
| DOI： |
| 分类号:TU528 |
| 基金项目:国家自然科学基金资助项目(50778055) |
|
| Property analysis of concrete under coupling action of sulfate and wet-dry cycles |
|
LIU Dao-wei1, LIU Ben-yi2, LI Xiang-dong1, YUAN Jie3
|
|
1.Heilongjiang Hydraulic Research Institute, Harbin;2.Water Resources Department of Heilongjiang Province, Harbin;3.Harbin Institute of Technology, School of Transportation Science and Engineering, Harbin
|
| Abstract: |
| Under the coupling action of wetting-drying cycles and sulfate, analysis studies of the effects of mineral admixture types, dosages and air content on mass loss, compressive strength and relative dynamic elastic modulus of concrete have been carried out. From the fourth wet-dry cycle, the quality loss of concrete specimens adding the mineral admixtures is less than that of benchmark concrete, and the reduction quality loss of the specimen mixed with ore powder is much greater; through the third dry-wet cycle, the increase in the compressive strength of the concrete specimens adding the mineral admixtures is greater than the benchmark concrete, and the reduction quality loss of the specimen mixed with ore powder is more remarkble; after the sixth wet-dry cycle, the relative dynamic elastic modulus of the concrete specimen adding mineral admixtures still remains over 60%; and mixing fly ash and mineral powder into the concrete specimens can effectively increase the resistance of the concrete specimens to damage caused by sulfate and wetting-drying cycles， thus improving concrete durability. With the composite dosage (the mix proportion of fly ash and mineral powder is 3:1) adding into the concrete specimens, the improved effects of the compressive strength of concrete are much more significant. At last, air entraining into the concrete specimens can improve the resistance of concrete to sulfate in the wet-dry cycles. |
| Key words: sulfate wet-dry cycles coupling action mineral admixture concrete durability dynamic elastic modulus |
