Neutralization of high pH and alkalinity effluent from recycled concrete aggregate by common subgrade soil.

Use of recycled concrete aggregate (RCA) as highway basecourse material conserves virgin aggregate, reduces energy consumption and CO emissions, and may also decrease costs during construction. However, concerns remain over possible negative environmental impacts associated with high pH (>11) effluent from RCA in contact with water. This study examines the reactive transport of high-pH and high-alkalinity water, modeled on RCA leachate, through model subgrade soils.