摘要
针对当前寒区高速铁路路基保温防冻胀材料(EPS板、XPS板、PU板等)耐久性差及局部保温措施效果不佳的不足,提出一种掺加粉砂的粉煤灰-水泥基泡沫混凝土作为路基保温型高强材料,将其施作在高速铁路路基基床表层及两侧边坡之上,形成一种新型的寒区高铁全断面保温路基结构。首先,以掺量比例为试验变量,采用冻融耐久性试验、抗压试验、抗折试验、导热系数测定试验等手段,综合分析泡沫混凝土的物理、力学性能的变化规律,得到性能最佳的掺量配合比;在此基础上,利用有限元仿真分析全断面保温路基结构的抗冻胀效果。结果表明:新型泡沫混凝土的最优掺量配合比为水泥含量40%、粉煤灰含量50%、粉砂含量10%;新型保温路基结构采用在基床表层全断面铺设10 cm厚最佳性能泡沫混凝土保温强化层、在边坡两侧增设50 cm厚细粒土包层的方案时,可以获得显著的保温隔热效果,有效抑制路基的冻胀。
In view of the poor durability of EPS,XPS and PU boards as well as the poor effect of local thermal insulation measures for subgrade of high-speed railway in cold regions,a new type of thermal insulation and high strength fly ash cement foam concrete mixed with silty sand was used as the whole section thermal insulation structure on the surface and side slopes of the high-speed railway subgrade.First of all,taking the proportioning ratio as the test variable,by means of freeze-thaw durability test,compression test,flexural test and thermal conductivity test,a comprehensive analysis of the physical and mechanical properties of foam concrete was carried out to obtain the best mix proportion.On this basis,the anti-frost heaving effect of the whole section insulation subgrade structure was analyzed by finite element simulation.The results show that the optimum mix proportion of the new foam concrete is 40%of cement,50%of fly ash and 10%of silty sand.The whole section of the new thermal insulation subgrade structure that is laid with 10 cm best performance foam concrete thermal insulation strengthening layer,and 50 cm silty sand layer on both sides of the subgrade slope,has good thermal insulation effect,effectively inhibiting the frost heave of the subgrade.
作者
刘晓贺
岳祖润
胡田飞
LIU Xiaohe;YUE Zurun;HU Tianfei(Postgraduate Department,China Academy of Railway Sciences,Beijing 100081,China;State Key Laboratory of Mechanical Behavior and System Safety of Traffic Engineering Structures,Shijiazhuang Tiedao University,Shijiazhuang 050043,China)
出处
《铁道学报》
EI
CAS
CSCD
北大核心
2022年第2期108-116,共9页
Journal of the China Railway Society
基金
中国国家铁路集团有限公司科技研究开发计划(N2020G056,P2021G047)。
关键词
高速铁路路基
泡沫混凝土
保温高强
冻胀
high-speed railway subgrade
foam concrete
thermal insulation and high strength
frost heaving
