Multi-field,time-varying behavior,and cracking mechanisms of early-age concrete in balastless track beds  

作　　者：Xiao LI Juanjuan REN Shijie DENG Zeyong ZHANG Xueyi LIU 

机构地区：[1]MOE Key Laboratory of High-speed Railway Engineering,Southwest Jiaotong University,Chengdu,610031,China [2]China MCC5 Group Corp.Ltd.,Chengdu,610063,China

出　　处：《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》2025年第3期212-225,共14页浙江大学学报(英文版)A辑(应用物理与工程)

基　　金：supported by the National Key R&D Program of China(No.2021YFF0502100);the National Natural Science Foundation of China(Nos.52278461 and 52308467).

摘　　要：Cracking of early-age concrete can occur in the track beds of high-speed railways due to changes in material properties,environmental effects,and construction processes.This is a multi-field,time-varying issue involving hydro-thermo-chemo-mechanical coupling.However,to date,research has not adequately described the early-age cracking mechanisms in track beds,and few risk control measures have been proposed.To solve this problem,we incorporated the hydration degree of concrete into multi-field coupling equations for early-age concrete,and set boundary conditions that account for environmental influences and various stress factors that typically cause early creep of concrete.A four-field coupled risk prediction model was built based on hydro-thermo-chemo-mechanical properties,and was used to calculate and analyze various time-varying behavior(including the risk and form of cracking)in the hydro,thermo,chemo,and mechanical fields of early-age concrete.Finally,we focused on material-related factors(maximum heat of hydration and peak heat release time),environmental factors(temperature difference between day and night,average daily cooling rate,and intensity of solar radiation),and construction technique factors(molding temperature,pouring time,and thermal insulation coefficient).The influence of these factors on the early-age cracking risk of the track bed was analyzed,and risk control measures against early cracking were proposed accordingly.

关 键 词：Ballastless track Early-age concrete Hydro-thermo-chemo-mechanical coupling Early cracking of track bed 

分 类 号：TU528[建筑科学—建筑技术科学]