Predicting the cracking behavior of early-age concrete in CRTS III track

Abstract

Early-age cracking of base plate may result in safety and durability problems for slab ballastless track. However, very limited studies are available on the mechanisms of early cracking of the base plate of the CRTS III slab ballastless track which is quite common in practice. In this study, a thermal–mechanical model was developed to investigate the cracking behavior of early-age concrete in base plate. The influences of curing method, demolding age, demolding temperature, the diameter of the steel bar, and the longitudinal continuous length were taken into account. It was found that the most unfavorable stress conditions in the early-age base plate were located at the corners between base plate and position-limitation recess, and the stress level at the middle point is the highest at longitudinal directions. This has been validated by field experiences. Furthermore, various measures were introduced to mitigate the early-age cracking risk.