POLYMER-MODIFIED CEMENT ASPHALT MORTAR AS INTERLAYER IN THE NON-BALLASTED TRACK OF HIGH-SPEED TRAIN

Non-ballasted track consists of a concrete slab bonded firmly to the concrete base by a cement asphalt mortar (CAM) as an interlayer for damping. In practice, interface bonding failure occurs on CAM. Styrene-butadiene rubber (SBR) polymer is proposed as a modifying material to increase the interface bonding strength of CAM. The problem of polymer modification in CAM is probably related to poor compatibility and workability. This study aims to investigate the effect of the SBR polymer pH value on the compatibility and workability in CAM. Compatibility is determined by separation rate. Zeta potential value describes polymer-modified asphalt emulsion (PMAE) activity. Workability is determined by funnel fluidity time and slump flow time. Results showed that increasing the SBR polymer pH value decreased the zeta potential of PMAE. Decreasing zeta potential to be value-neutral results in destabilized asphalt droplets, demulsified, separated water, and asphalt coalescence. Finally, the asphalt coalescence is covered