Portland tries permeable interlocking concrete street pavements

Sustainability with paving blocks

Fig. 1 The City of Portland is not new to permeable pavements. The Multnomah Arts Center parking lot was one of the early
projects. Ref: Interlocking Concrete Pavement Magazine.

Fig. 2 The permeable pavers receive runoff into an open-grade aggregate base, or “drainage blanket,” that extends under the asphalt across the entire street. This boosts water storage and infiltration capacity.

Fig. 3 Mechanical installation equipment places the permeable pavers in the final laying pattern over the bedding course.

Fig. 4 The bedding material was an Oregon DOT standard
for small size, open graded stone.

Fig. 5 The drainage blanket of open-graded stone base ranged in size from 4 in. (100 mm) to 1/16 in. (2 mm), an Oregon DOT standard for large size, open-graded stone.

Fig. 6 The drainage blanket base runs under the curbs across the width of the street. Geotextile was placed over the top of the
drainage blanket in the asphalt center strip and dense-graded base compacted into place as shown here. Temporary driveways built with base and plywood allowed access to residents’ driveways.

Fig. 7 A makeshift screed levels the bedding course for the
permeable pavers.

Fig. 8 The width of new curb was set to accommodate mechanical placement of two paver layer widths within the 6 ft – 10 in. (2.1 m) wide parking strips. Some adjustments were necessary to fit the layers within the new curbs and the mostly uneven old curbs adjacent to the residences.

Fig. 9 Installed pavers were compacted, the openings filled with the bedding stone and compacted to about 3/8 in. (10 mm) above the new concrete curbs.

Fig. 10 Capped, 4 ft (1.2 m) deep, 6 in. (150 mm) diameter
perforated pipes serve as wells to monitor infiltration rates.

1 Known for its leadership in environment stewardship, The City of Portland, Oregon, placed over 19,000 sf (1,765 m²) of permeable interlocking concrete pavements in its Westmoreland neighborhood. The uses concrete products were produced by ICPI-Members. This article shows the former implementation and first results. Furthermore this text should spark interest to attend the 9th International Conference on Concrete Block Pavement in Buenos Aires.

Portland, Oregon, (population 551,000) endeavors to maintain its reputation as an environmentally friendly and innovative city. In 2004, the city government confirmed its commitment to both by constructing a permeable interlocking concrete pavement (PICP) pilot project using some 19,000 sf (1,765 m2) in its Westmoreland neighborhood. The well-kept, 80-plus year old neighborhood required water line reconstruction following installation of large-diameter sanitary sewer pipes in 2003. Rather than merely repave the streets with asphalt, the City’s Bureau of Environmental Services and the Portland...