Mechanical properties and damage mode of cemented tailings backfill in an acidic environment

SYNOPSIS The properties and deterioration in strength of cemented tailings backfill (CTB )in the underground acidic environment under oxidizing conditions were studied. X-ray diffraction analysis scanning electron microscopy surface CTB was carried out, sulphuric acid corrosion mechanism elucidated. tested included compressive strength, elastic modulus, cohesion, internal friction angle, variation hydrogen ion concentration, stress-strain relationship different periods. damage model established considering effects parameters such as time strain on evolution. It found that cohesion (binder effect), angle increased at first then decreased with exposure time. In long term, peak stress while increased; deformation modulus also decreased. caused by load related means a mathematical model, which revealed relationships between attack, load, to complex environments. During corrosion, expansion gypsum ettringite microfractures CTB. With increasing time, micro-cracks developed proliferated. be dissolution ions sulphate reaction produces an expansive substance, resulting Keywords: environment, porosity, backfill, evolution model.