摘要
针对斜拉桥混凝土超高桥塔因温度和收缩引起的拉应力较大,表面易出现施工裂缝、麻面、蜂窝等现象,基于皮肤效应的仿生理念,对斜拉桥超高塔柱进行分层结构设计,通过设置内侧结构层混凝土及外侧功能层混凝土,提出了一种新型的“梯度功能混凝土”塔柱结构,并采用材料性能试验和结构模型试验进行研究。结果表明:功能层混凝土坍落度、扩展度分别为210 mm、510 mm,具有较好的工作性和可泵送性;抗拉强度达到5.2 MPa;模型表面仅存在少量宽0.02~0.05 mm不可见裂纹;室内试验碳化深度为0.2~0.5 mm,平均水渗透深度与氯离子扩散系数DRCM分别为16 mm和1.2×10-12 m2/s。梯度混凝土超高桥塔具有较好的抗裂性、耐久性和美观性,已成功应用在池州长江公路大桥,效果较好。
The high tensile stress caused by temperature and shrinkage leads to the appearance of construction cracks,pitted surfaces and honeycomb phenomena in ultrahigh concrete tower of cable-stayed bridge.Based on bionic idea of skin effect,a new type of"gradient functional concrete"tower is proposed,namely to set the outside high-performance concrete functional layer and the inside ordinary concrete structure layer,and the properties of which are examined via material performance tests and structural model tests.The results demonstrate that the slump and expansion of concrete in functional layer is 210 mm and 510 mm,respectively,indicating that the concrete has good workability and pumpability.The tensile strength of the concrete reaches up to 5.2 MPa.There are only a few invisible cracks between 0.02 mm and 0.05 mm on the surface of gradient concrete full-scale model.The carbonation depth is 0.2 to 0.5 mm,and the average penetration height and chloride diffusion coefficient D are 16 mm and 1.2×10m/s,respectively.The gradient concrete ultrahigh tower has good cracking-resistant capacity and durability,and is aesthetically pleasing as well,which has been successfully used in the towers of Chizhou Changjiang River Highway Bridge.
作者
朱瑞允
阿布都热依木江·库尔班
任伟新
ZHU Rui-yun;Abudureyimujiang Kuerban;REN Wei-xin(Anhui Transportation Holding Group Co. ,Ltd. ,Hefei 230088,China;School of Civil and Hydraulic Engineering,Hefei University of Technology,Hefei 230009,China)
出处
《世界桥梁》
北大核心
2022年第4期88-94,共7页
World Bridges
基金
安徽省交通控股集团科技项目(2019010011)。
关键词
斜拉桥
桥塔
梯度混凝土
结构层
功能层
性能研究
cable-stayed bridge
tower
gradient concrete
structural layer
functional layer
performance research
