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Ballast is one of themain structures for the railway tracks. It can resist the lateral movementunder dynamic loading transferred by the passing trains with repeatedly. Undersome circumstances, ballast can suffer degradation or breakdown due to therepeated loading and maintenance. Ballast is easily exposed to the weatherbecause it is laid on the track. Acid rain affects the performance of therailway track near the industrial and urbanarea. As a result, it starts to foul and the small chips from ballast filledthe void, as well as reduce the shear strength of ballast particles. Thissituation can contribute into the increasing of maintenance frequency andcosting. This paper examines the potential of rubber inclusions in increasingthe shear resistance of rubber-ballast composites in simulated water and acid soakedconditions with several configuration. This lab-based exploratory work is only static load simulation in conventional shear boxsetup measuring 60 mm × 60 mm.The aggregates size is 10 times smaller than actual size of ballast. In orderto identify the shear resistance deterioration of rubber-aggregates mixtureunder poor drainage conditions by soaked a batch of aggregates in water andacid solution for 2 weeks to simulate accelerated weathering effects. The shearresistance did not rise dramatically with the rubber reinforcement. Thissusceptible shear strain plots indicate ductile behaviour on theaggregates-rubber composites. This is evident by the linear rise of shearstress with strain up to approximately 10% for the control samples (CS) untilit reaches a constant value. Note that all the specimens including CS are in aloose state during the testing because there were no tamping been applied onthe samples. Overall the circular patch (CP) specimen was the most favourablethan the other configurations. Both mechanisms contributed to the reducedoverall subsistence, accompanied by an increase in the shear resistance. Theinclusion of rubber elements apparently prevented the dilation of the granularmaterial when approaching the shear failure and the reducing the settlement. |
