Investigated stress-strain relationships of municipal solid waste incineration bottom ash

Abstract

To investigate the stress-strain relationship of municipal solid waste incineration bottom ash (MSWIBA), taking MSWIBA samples with a dry density of ρd = 1.5 g/cm3 as examples, a series of consolidated drained triaxial tests were carried out on MSWIBA. The test results showed that the stress-strain relationship of MSWIBA showed an obvious strain softening phenomenon when their curing ages and confining pressure were relatively small, and the stress-strain relationship showed an obvious strain hardening phenomenon when the curing ages and confining pressure were large. The improved Duncan-Chang model can reflect the strain softening and strain hardening phenomenon of MSWIBA. There is a transformation phenomenon of the stress-strain relationship in MSWIBA, and the curing age and confining pressure are the main influencing factors of its transformation phenomenon. The ‘postfailure modulus’ was proposed to distinguish the transformation phenomenon of MSWIBA, and its transformation mechanism was analyzed in detail. A practical stress-strain relation model is proposed for MSWIBA, which can take into account the transformation phenomenon. Moreover, the patterns of the stress-strain relationship were identified based on the critical confining pressure.