STRENGTH CHARACTERIZATION OF BITUMINOUS CONCRETE MIXES

Abstract

Elastic and viscoelastic structural analyses of flexible pavements as layered systems are increasingly becoming a part of working design practice. This is largely due to the readily available computer programs which have consl.derably simplified the conduct of such analyses and the understandability of the results. An elastic analysis program requires the input of elastic parameters (stiffness modulus or Poisson's ratio) for each material in the pavement structure. The stiffness characteristics of bituminous mixtures are influenced parti-cularly by the stress environment in 3D space and tempera-ture conditions, which must necessarily be considered in the material characterization. In this study an attempt is made to characterise the elastic response of bituminous concrete mix of specifi-cations recommended by Indian Roads Congress for flexible pavements surfacings. The stress—strain characteristics have been studied both under triaxial tension—compression using hollow cylindrical specimens, as well as under bendihg using the beam specimens. The following studies have been made : influence of axial stress and axial strain on elastic modulus, (iv) (b) influence of radial stress on elastic modulus, (c) influence of temperature on elastic modulus, (d) relationship between stiffness modulus, flexural stress 7and