LAUSR

Abstract Solidification using binders is a widespread technique that provides civil engineering applications for silt with poor geotechnical performance. The aim of this study is to investigate the effects of a self-developed lab-made binder (named SEU-2 binder) on the deformation characteristics of silt. For this purpose, a series of one-dimensional consolidation tests, unconfined compressive tests, consolidated undrained triaxial compression tests, Scanning Electron Microscopy (SEM) tests and X-ray diffraction (XRD) tests were conducted on silt specimens and SEU-2 binder solidified silt specimens at 7, 28 and 90 days of curing. Brittleness index was introduced to evaluate the soft-hardening effect of solidified silt quantitatively. It was found that due to SEU-2 binder addition, the deformation characteristics of silt was improved. The initial void ratio and compression index decreased with the increase of SEU-2 binder content. Unconfined compressive strength (UCS) increased with curing time and SEU-2 binder content, while failure strain decreased. Moreover, the shear strength parameters of silt was enhanced due to SEU-2 binder addition, the cohesion increased with the increase of SEU-2 binder content, while the internal friction angle increased and then hardly changed. Additionally, under unconfined compressive tests, the stress-strain curves transformed from dwarf type to lanky type with SEU-2 binder dosage increasing. Under consolidated undrained triaxial compression tests, the stress-strain curves of SEU-2 binder solidified silt behaved as strain softening, while silt exhibited a strain hardening character under high confining pressure, exhibited a strain softening character under low confining pressure. The brittleness index increased with the increase of SEU-2 binder content. SEM analysis revealed that silt structure became denser with an increasing SEU-2 binder content. Furthermore, more network and fibrous hydrates such as C-S-H appeared with the increase of curing time.