Polyurethane grouting materials with different compositions for the treatment of mud pumping in ballastless track subgrade beds: properties and application effect

Abstract Mud pumping in subgrade beds under ballastless tracks will deteriorate the dynamic performance of infrastructure railway lines, reduce smoothness and seriously affect comfort safety trains. Due to their good mechanical properties, two-component polyurethane materials can be used for grouting treat fouling problems caused by track mud pumping. To develop a formula suitable treatment pumping, we first performed indoor experiments investigate properties gelation time elastomers synthesized with different raw material composition ratios, determine an optimal ratio materials. Then, conducted field test verify remediation effect fabricated according design ratio. The results showed that selected ratios improved contact characteristics between surface layer bed base plate area, coordinating response structure bed. Thus, obtained could renovate areas effect.