This study investigates the mechanical behavior of geosynthetic-reinforced composite materials, Sand-
Tyre Crumb Mixtures (STCM) by conducting Unconsolidated Undrained (UU) triaxial tests. The main
objective of this study is to evaluate the stress-strain characteristics of STCM in geosyntheticreinforced
works. The mechanical behavior of geosynthetic-reinforced STCM has been investigated
by varying proportions of tyre crumbs (50% and 75% tyre crumbs by volume), type of geosynthetic
(geotextile, geogrid and geonets), number of geosynthetic layers (1 to 4 layers) and confining pressure.
A series of UU triaxial tests has been carried out to select the optimum size of tyre crumb. Tyre crumb
that provides comparatively higher stiffness is considered as the optimal size and has been used in the
investigation on geosynthetic-reinforced STCM. The results demonstrate that STCM reinforced by
geotextile has enhanced peak strength, axial strain at failure, energy absorption and ductility capacity.
Also, it has been found that the type of geosynthetic significantly influences the shear strength of