赵口引黄灌区渠道混凝土耐久性研究

Durability of Channel Concrete in Zhaokou Yellow River Diversion Irrigation Area

赵口引黄灌区位于河南省豫东平原,灌区渠道会受到冻融循环与泥沙磨蚀的共同作用,在两者耦合作用下必然会加剧混凝土服役性能的劣化。基于集中沉沙和分散沉沙两种引黄沉沙方式,研究了冻融-泥沙磨蚀耦合作用下混凝土的耐久性能,结果表明:采用集中沉沙方式可只考虑冻融作用对混凝土服役性能的影响;采用分散沉沙方式时,混凝土冲刷磨蚀速率与含沙量、冻融次数密切相关;随着水流含沙量和冻融次数的增加,混凝土的磨蚀速率加快,服役年限也相应缩短。根据计算结果,针对泥沙含量常年在0.5~5、5~10、10~15 kg/m3的渠道,建议在工程运行20、15、10 a时对渠道混凝土进行修补加固。

Zhaokou Yellow River diversion irrigation area is located in the east plain of Henan Province and the concrete structures will be af⁃fected by the coupling action of freeze⁃thaw and sediment erosion,aggravating the deterioration of concrete service performance.Based on centralized sedimentation and decentralized sedimentation methods,the durability of concrete under the coupling action of freeze⁃thaw and sediment erosion was studied.The results show that only the effect of freeze⁃thaw on the service performance of concrete can be considered by using the centralized sedimentation method.When the decentralized sedimentation is adopted,the erosion rate of concrete is closely related to the sediment concentration and freeze⁃thaw times.The abrasion resistance and service life of concrete decrease significantly with the increase of sediment concentration and freeze⁃thaw times.According to the calculation results,it is recommended to repair the concrete in about 20,15 and 10 years for the channels with sediment concentration of 0.5-5,5-10 and 10-15 kg/m3 respectively.