Freeze-thaw Damage Mechanism and Service Life Prediction of High-speed Railway Ballastless Cast-in-place Track Concrete
The ballastless cast-in-place track in some severe cold regions suffers from freeze-thaw pulverization.In order to reveal the freeze-thaw damage mechanism and further to predict the service life of ballastless cast-in-place track con-crete,in this paper,a finite element analysis method was used based on the capillary adsorption,hydrostatic pressure and damage fracture theory.The results show that the freeze-thaw effect of pore water is the main reason for the freeze-thaw pulverization of the surface layer of cast-in-place track bed concrete.Meanwhile,the surface freeze-thaw scaling firstly occurs in the edges and corners before developing to the center areas of ballastless cast-in-place track concrete un-der freeze-thaw conditions.By analyzing the degree of freeze-thaw damage to ballastless cast-in-place track under mini-mum environmental temperatures ranging from-24 ℃ to-3 ℃ and with concrete water absorption rates between 0.2％and 1.0％,this paper established a life prediction model for ballastless cast-in-place track concrete to predict the freeze-thaw life of ballastless cast-in-place track concrete under different water absorption rates and minimum ambient tempera-tures,aiming to provide reference for the freeze-resistant design of ballastless cast-in-place track concrete in cold re-gions.
high-speed railwayballastless track concretefreeze-thaw pulverizationservice life prediction
NETL
NSTL
万方数据
