Flexural fatigue strength of demolition aggregates stabilized with alkali-activated calcium carbide residue

摘要

Replacing the base and subbase layers in flexible pavements and sub-ballast layer in railway tracks with recycled materials has attracted significant attention from industry and researchers alike. The semi-rigid stabilized layers in the flexible pavement structure and railway tracks sustain high flexural and tension stresses which reduces the serviceability life of the superstructure. The flexural and compressional modulus of the stabilized materials under repeated loads and at at-rest k(0) condition is highly dependent on the specifications of the binder. Industrial by-products including calcium carbide residue (CCR), Fly Ash (FA) and Slag (S) were utilized to improve the compressional resilient modulus, flexural strength, durability and fatigue life of recycled aggregates. The variation of ductility in the blend with different precursors indicated that the service life of the stabilized layers not only depended on the strength but was also controlled by the deterioration rate of the flexural modulus and stiffness of the sample. The ductility of binder with aluminosilicate gels fabric can potentially absorb the stresses of the cyclic loading and postpones development of tension cracks. (C) 2018 Elsevier Ltd. All rights reserved.