Recycled concrete aggregate incorporated cold bituminous emulsion mixture: Mechanical, environmental and economic evaluation

The present study aims at exploring the effect of partially replacing virgin aggregates with recycled concrete aggregate (RCA) in cold bituminous emulsion mixture (CBEM). In the study different CBEM samples were prepared by replacing 10–50% virgin aggregates with RCA. These samples were tested for mechanical properties and moisture susceptibility parameters such as Marshall Stability, Marshall Quotient (MQ), Indirect Tensile Strength (ITS), Retained Stability (RS) and Tensile Strength Ratio (TSR). In order to deal with CBEM's inherent issues like lower strength, higher air voids, higher moisture susceptibility, apart from conventional stone dust filler two additional fillers lime and cement were also used. Environmental and economic analysis of all the samples were also carried out by calculating the cost and CO2-eq of the mixtures. Test results showed that RCA incorporation in CBEM has positive impact on the properties like Marshall Stability, MQ and ITS while it has negative impact on the moisture susceptibility. Inclusion of lime and cement fillers solved the issues related with moisture susceptibility. Further based upon the economic and environmental analysis it was found that RCA incorporated CBEM has significant economic and environmental benefits. Cement and lime fillers increased cost and CO2-eq of the mixtures but it was still lower than conventional HMA.