Concrete mix design: Optimizing recycled asphalt pavement in Portland cement concrete

In contemporary construction projects, there is a growing trend towards incorporating Recycled Asphalt Pavement (RAP) into Portland Cement Concrete (PCC). However, a significant challenge lies in formulating the mixture to achieve the desired strength for practical applications. This study delves into the influence of RAP on formulation of PCC mixtures. Conventional aggregates were systematically substituted with RAP at proportions of 25 %, 50 %, 75 %, and 100 % relative to the overall weight of the mixture. The study comprehensively analyzed various parameters throughout both the initial and solidified phases, encompassing modulus of elasticity, unit weight, workability, and compressive strength. The efficacy of PCC incorporating RAP can be standardized through the application of an extended water/cement ratio approach. Moreover, the key factors influencing the strength development of PCC containing RAP were identified as the residual water content after hardening (w_u) and the asphalt fraction weight percentage in the aggregate mixture (θ_AS). A straightforward and precise technique for designing the strength of PCC using RAP was suggested. This document presents the design criteria and suggestions for using PCC including RAP. The outcomes offer crucial insights regarding the utilization of RAP as a greener material in PCC applications on a substantial scale.