Reclaimed Asphalt Pavement Stabilized Using Crushed Concrete Waste as Highway Pavement Material

Abstract

Pavement rehabilitation and reconstruction generate a large volume of reclaimed asphalt pavement (RAP) waste. Also, large quantities of crushed concrete waste (CCW) are generated from building demolitions and constitute a principal component of municipal solid waste consisting of concrete, sand, brick, rock, metals, and timber. This paper present the results of a laboratory evaluation of the characteristics of RAPs stabilized using CCW with a view toward determining their suitability for use as flexible pavement material. The mixtures were subjected to British Standard light (standard Proctor) compactive efforts to determine the compaction characteristics and California bearing ratio (CBR). Test results show that the properties of RAP waste improved with CCW treatment. The maximum dry density decreased, and the optimum moisture content increased, with increased CCW content in the mixes. Optimum CBR values of 28.06 % (unsoaked) and 32.81 % (soaked for 24 h) were recorded for a 50 % RAP + 50 % CCW mix. With the potential of a time-dependent increase in strength in view, the 50 % RAP + 50 % CCW mix with a recorded CBR value of 32.81 % (soaked for 24 h), which satisfied durability requirements with insignificant water absorption, can be used as a sub-base material in flexible pavement construction. This research provides results of the evaluation of RAP waste stabilized using CCW as a highway construction material, as based on CBR determination. Further work may be encouraged in order to assess the resilient modulus of this material under cyclic load.