Cyclic Behavior of Cellular Glass Aggregates: An Experimental Comparison with Natural Aggregates

The construction sector is a major user of natural materials and a key contributor to global carbon emissions. To tackle these environmental challenges, the use of recycled products has become increasingly important in modern engineering. Cellular glass aggregate (CGA), made from recycled glass, is a material with potential as a sustainable alternative to natural aggregates. This study characterizes the cyclic behavior of CGA using a large-scale triaxial apparatus, focusing on seismic-relevant properties such as the damping ratio and Young's modulus. Local displacement transducers (LDTs) were implemented to improve measurement at small strains. The results show that CGA exhibits strain-dependent stiffness and damping behavior comparable to natural aggregates at moderate strains (10^-4-10^-3). The Young's modulus ranges from approximately 300 to 600 MPa, while damping ratios remain at approximately 2-3% for low values of strains (10^-5). As strain increases to moderate levels (10^-4-10^-3), the Young's modulus decreases to approximately 80-250 MPa, accompanied by an increase in damping ratio to approximately 4-6%. At higher strain levels ≥ 10^-3, the Young's modulus further reduces to approximately 40-80 MPa, while damping ratios increase to approximately 7-10%. These stiffness degradation and damping trends fall within the ranges reported for sands and gravelly soils in the literature, indicating that CGA can reproduce the cyclic mechanical behavior of natural aggregates under well-defined strain conditions.