摘要
防止抽水蓄能电站堆石坝面板混凝土的开裂是电站长期安全运行的重要保障,在电站运行过程中,温差循环对面板混凝土耐久性的影响通常容易被忽视。在面板混凝土中掺入聚丙烯纤维,采用环境试验箱模拟5~85℃高低温循环作用,研究该高低温循环作用对纤维增强面板混凝土力学性能的影响。结果表明:450次高低温循环作用后,普通混凝土和聚丙烯纤维增强混凝土抗压强度较90次高低温循环时分别下降了29.1%、26.3%,极限拉伸应力分别下降了43.1%、32.5%;聚丙烯纤维的掺入可以明显降低混凝土的力学性能损失,且对混凝土拉伸性能的改善程度是抗压强度的5倍左右;聚丙烯纤维在抵抗大温差循环作用下混凝土的拉伸破坏中起到了良好的阻裂和桥架作用,纤维增强混凝土表现为延性破坏特征。
Preventing cracking of panel concrete in pumped storage power plant rockfill dams is an important safeguard to ensure the long-term safe operation of the power plant.In the process of power plant operation,the influence of temperature difference cycling on the durability of panel concrete is usually easy to be ignored.In this paper,polypropylene fiber was added into the panel concrete and an environmental test chamber is used to simulate the high and low temperature cycling within the range of 5~85 ℃ to study the effect of cycling on the mechanical properties of fiber-reinforced panel concrete.The results show that compared to 90 cycles,the compressive strengths of ordinary concrete and polypropylene fiber-reinforced concrete decreased by 29.1% and 26.3%,and the ultimate tensile stresses decreased by 43.1% and 32.5%,respectively,after 450 cycles.The incorporation of polypropylene fibers can significantly reduce the loss of mechanical properties of concrete,and the degree of improvement of tensile properties of concrete by polypropylene fibers is about 5 times of the compressive strength.Polypropylene fibers played a good role in preventing the tensile damage process of concrete under the action of large temperature cycling as a crack-blocking and bridging effect,and the fiber-reinforced concrete showed ductile damage characteristics.
作者
林文华
LIN Wenhua(Fujian Xianyou Pumped Storage Co.Ltd.,Putian 351200,China)
出处
《新型建筑材料》
2024年第5期74-77,共4页
New Building Materials
基金
国网新源集团有限公司科技项目(SGXYKJ-2022-023)。
关键词
高低温循环
面板混凝土
聚丙烯纤维
纤维增强混凝土
力学性能
high and low temperature cycling
panel concrete
polypropylene fibers
fiber-reinforced concrete
mechanical properties
作者简介
林文华,男,1973年生,硕士,高级工程师,主要从事水利研究,E-mail:wenhua-lin@sgxy.sgcc.com.cn。
