Laboratory Investigation on Preplaced Ballast Aggregate Concrete Deterioration over Freezing–Thawing Cycles

Abstract

One of the major gaps in previous research on the mechanical behavior of ballasted railway tracks converted into slab tracks using the preplaced aggregate concrete technique is its durability against freezing and thawing cycles. The present study pioneers at investigating the Preplaced Ballast Aggregate Concrete (PBAC) deterioration during freezing–thawing cycles, in which several freeze–thaw tests were carried out to measure the weight loss of PBAC samples during various freezing–thawing cycles, as well as the reduction in both compressive/tensile strengths and the relative dynamic modulus of elasticity. Moreover, the image acquisition of the PBAC samples was performed using a digital microscope and subsequently, an image processing technique was utilized to find a relation between the surface defect area at each imposed cycle and the number of cycles as a lifetime representative. As a result, an equation was developed to predict the defect frequency versus imposed cycles and the defect area generated to find the serviceability lifetime of PBAC in aggressive weather conditions. It was concluded that such PBAC can tolerate 6.16 years in the regions with full freezing–thawing weather conditions.