RHEOLOGICAL CHARACTERISTICS OF BITUMINOUS CONCRETE MIXES

Abstract

Due to the viscoelastic behaviour of the bituminous pavement materials9 the elastic theory is not suitable for the design of flexible pavements under a constant loading or loading at very slow speeds. Hence a need exists for the viscoelastic design of the flexible pavements. Stress-strain response of the bituminous mix with the duration of loading is the basic input needed for such analysis. The present study deals only with viscoelastic response of bituminous concrete mix of I.R.C. specifica-tions, used as wearing course for flexible pavements. Creep characteristics of the mix have been studied both under compression as well as under tension. The following relationships have been established from compression as well as tension creep tests. [a] Stress-strain relationship for different load-ing times. [ID] Creep compliance versus stress relationship under different loading durations. [c] Creep strain versus duration of loading rela-tionship for different sustained stress levels. APPlications of the study to the design and service performance of bituminous pavements have also 'been. described.