摘要
本文对拉荷载条件下铁路工程混凝土中的氯盐传输行为进行研究.采用可靠度模型对两种混凝土桩在拉荷载-氯盐侵蚀协同作用下的服役寿命进行预测,分析拉荷载对混凝土中氯盐传输的影响及其对混凝土服役寿命的影响.结果表明,两种混凝土桩的使用寿命均超过设计使用寿命.与不受力混凝土相比,施加30%拉应力后,混凝土在不同龄期内的氯离子扩散系数均稍有增大;外加拉应力在一定程度上加速了混凝土内的氯离子扩散,导致混凝土的服役寿命缩短.在进行铁路工程材料耐久性设计时,应重点关注受拉构件和构件受拉区的材料设计.
The transport behavior of chloride ions in concrete in railway engineering under external tensile load was studied. A reliability model was used to predict the service life of two concrete beams under the combined action of tensile load and chloride attack. The effect of tensile load on the chloride transport and its impact on the service life of concrete was analyzed. Results showed that the service life of the two tested concrete beams both exceeded the design service life. Compared with unstressed concrete, the diffusion coefficient of chloride ions in concrete increased slightly in different ages after 30% tensile stress was applied. The external tensile stress accelerated the diffusion of chloride ions in concrete to a certain extent, resulting in a short service life. For the durability design of railway engineering materials, attention should be paid to the tension components and the tension regions which bear tensile load in the service period.
作者
李金永
曹银
Li Jinyong;Cao Yin(China Railway 19th Bureau Group Co. Ltd.,Beijing 100176, China;China Building Materials Academy, Beijing 100024,China)
出处
《铁道建筑技术》
2019年第9期11-14,43,共5页
Railway Construction Technology
基金
中铁十九局集团有限公司科技研究开发计划项目(2010-18B)
关键词
铁路混凝土
服役期评价
试验研究
拉荷载
氯盐侵蚀
concrete in railway engineering
service life evaluation
experimental research
tensile load
chloride attack
