Should a dense-graded or open-graded aggregate base be used under PICPs?

a view of houses in a neighborhoodAn open-graded base is most commonly used because it has water storage capacity (void space between the aggregates) of typically 30% to 40%. The stone sizes in open-graded bases can be as large as 3 in. (75 mm) and as small as 1/4 in. (6 mm). There is typically a thinner layer of small stone sizes (6 mm to 1 mm) used for bedding directly under the concrete pavers. The bedding and base bedding material maximizes storage, filtering, and treatment of pollutants in stormwater runoff entering the pavement surface. Open-graded bases are preferred because of the storage and treatment benefits.