DESIGN OF HOT MIX ASPHALT USING BAILEY METHOD OF GRADATION

Abstract

This study investigates the properties of Hot Mix Asphalt (HMA) mixtures designed using Bailey method of gradation and compared with conventional method of gradation. Bailey method is a systematic approach in blending aggregates that provides aggregate interlocking as backbone of the structure and develop strong aggregate skeleton for rut resistance and durability. The Bailey method allows the designer to select an aggregate skeleton that will be more resistant to permanent deformation and to adjust the VMA (voids in mineral aggregate) by changing packing of coarse aggregate and fine aggregate with sufficient asphalt binder. Two hot mix mixtures considered in this study are Bituminous concrete (BC) grade 1 and grade 2. The mixtures have nominal maximum particle size (NMPS) of 19 mm and 13 mm. The aggregate structure designed using Bailey method are applied in Marshall method of mix design to obtain Marshall properties according to Indian standards and gradation parameters were compared with requirement of MORTH specifications. The tests for determining volumetric properties and Indirect Tensile Strength of mix are conducted and compared with aggregate structure designed using conventional method of gradation. Further the rutting characteristics of both gradations are modelled using Rolling Compactor cum Rut Analyser (RCRA) equipment for different field temperatures. Keywords: