Assessment of Expanded Clay Aggregate for Use in Railroad Embankments

Ground settlement is a major challenge in railroad embankment construction and widening, threatening both track stability and nearby infrastructure. Settlement arises from two mechanisms: immediate elastic compression of soils and longer-term consolidation. To mitigate these risks, lightweight aggregates (LWAs), such as expanded clay, offer a promising solution by reducing embankment load and associated settlement. Expanded clay is nearly half the weight of conventional aggregates, with high internal friction angle and excellent drainage, enhancing stability and reducing hydrostatic pressure. However, its long-term performance under cyclic train loading remains uncertain. To address this, a laboratory testing program, including large-scale Cyclic Direct Simple Shear (CDSS) tests, was developed to simulate railroad loading conditions and evaluate the durability and deformation behavior of expanded clay. This study aims to validate LWAs as a viable alternative for minimizing settlement without compromising long-term track performance.