Optimization of the road binder used in the base layer in the road construction

Abstract

AbstractThe research focused on the application of mixed binder system to the hydraulically bound mixes used in road base (HBM). This paper presents the outcome of the tests for the mechanical characteristics of the HBM road base in terms of the binder type used. Seven binders were prepared in a laboratory by blending three primary constituents: Portland cement CEM I 32,5R, fluidised bed combustion fly ash and cement kiln dust (CKD). The proportions were selected according to the experimental design. The percent amount of the binder in the hydraulically bound mixture was 6%. Two types of aggregate were used as the mineral material in the base. The composition of the mixtures was designed based on the Proctor method. The influence of the binders on the properties of the HBM road base was evaluated by determining the compressive strength at 7, 14, 28 and 42days of curing, frost resistance and water absorption. The test results were used to optimise the binder composition with respect to the road base characteristics and to establish the recommended road binder composition