Comparative Analysis of Laboratory and Prototype Models of Pervious Concrete Mixes Containing Reclaimed Asphalt Pavement Aggregates

Abstract

Pervious concrete (PC) is lightweight concrete with higher porosity and permeability than conventional concrete, making it suitable for reducing storm-water runoff from pavements. Incorporating reclaimed asphalt pavement (RAP) aggregates as a replacement for natural aggregates will likely enhance the porosity and permeability of PC pavement mixes. This paper provides a comparative analysis of the influence of RAP in PC pavement mixes when prepared in two different conditions (laboratory and field). To simulate field conditions, a prototype model tank consisting of subgrade and reservoir layers and a PC slab was constructed. Studies showed that the compaction types and efforts affect the RAP-PC prototype slab and require 50% extra cement to achieve the recommended 28-day compressive and flexural strength of PC pavements. The prototype model tank’s surface infiltration (SI) test demonstrated a higher permeability but less density than laboratory-prepared specimens, indicating that the use of binary graded RAP aggregates contributes to a porous network structure, which improves the transport properties of PC pavement mixes. A correlation with a high R2 value between the laboratory and prototype model tank was also established, indicating the coexistence of a relationship between the density and porosity of laboratory and Prototype-PC pavement mixes. Interestingly, it was reported that the use of standard proctor hammer compaction to cast laboratory specimens produced the same effect when the vibratory hammer compacted the RAP-PC prototype for 20 s. It is, therefore, recommended that 25% to 50% of RAP be used as a coarse aggregate replacement to produce PC pavement mixes.