Table 7 Construction requirements of porous asphalt in cold regions

Weather and Site Conditions

• ≥ 10 °C (50 °F) [42, 45, 59]

• ≥ 15.6 °C (60 °F) and do not place on raining days and over a wet surface [40]

Plant Mixing

• ≤ 177 °C (350 °F) (ODOT 2016)

• Increase dry mixing time [40] and wet mixing time [29] when a fiber is used.

Silo Storage

• ≤ 4 h in the non-insulated silo and 8 h in the insulated silo [5]

• ≤ 2 h in Maine Mall project [44]

• ≤ 1.5 h in MnROAD test sections [32]

Hauling

• Haul vehicles with a clean and smooth dump bed coated with a non-petroleum asphalt release agent [29, 59]

• Avoid long haul distance [59];

• WMA technology can be used to extend the paving season and allow long haul distance.

• Avoid segregation when PA mixtures are deposited from haul vehicles [42]

Placement Thickness

• One lift for small projects [6]

• Two lifts for thicker cross-section [6] or large projects in cold weathers [59]

• ≤ 10.2 cm (4-in.) for one lift [42, 45]

• ≥ twice the maximum aggregate size in PA for one lift [42]

Roller Selection

• Smooth double steel-wheeled roller with a weight of 8–10 tons [6, 17]

• An additional small roller with a weight of 1–1.5 tons could be used for finishing rolling to achieve a smooth finished surface [6, 59]

• The pneumatic-tired roller is prohibited ([29], [36], and [40])

Rolling temperature

• Sufficient cool to resist roller [42] and avoid over compaction [9]

• UNHSC [59]: breakdown (135–162.8 °C (275 °F − 325 °F)); intermediate (93.3–135 °C (200 °F–275 °F)); finishing (65.6–93.3 °C (150 °F − 200 °F)); and cessation (79.4 °C (175 °F)).

Rolling passes and patterns

• Hansen [17]: 2–4 passes

• Peabody [44]: a minimum of 3 passes for the Maine Mall project

• ASCE [6]: 2–3 passes

• Minnesota Asphalt Pavement Association (MAPA) [36]: 1–2 passes

• APWA-WA-LAGSPs [5]: use a density gauge to monitor in-place air voids during the compaction and decide the cessation of rolling

• Pennsylvania Department of Transportation (PennDOT) [45]: construct two test sections to develop rolling patterns

• New York State Department of Transportation (NYSDOT) [40]: construct a 1000 square feet test section to develop rolling patterns

• Oregon Department of Transportation (ODOT) [42]: a minimum of four passes for breakdown and intermediate rolling and additional passes for finishing rolling

Joints

• Longitudinal joints: place adjacent lane with an overlap of the compacted lane by 2.5–5.1 cm (1–2 in.) [45]; staggered and offset at least 15.2 cm (6 in.) [42]

• Transverse joints: Spray Type RS-1 or equivalent emulsified asphalt to achieve good bonding [59]

Inspections

• Smoothness, thickness, in-place air voids tested by density gauge [40]

• Infiltration rate: ≥ 84.6 mm/min. (200 in./h) (Pennsylvania Department of Transportation (PennDOT) [45])); ≥ 42.3 mm/min. (100 in./h) [5]

Curing time before opening to traffic

• Cure at least 24 h ([17, 36], and [40])

• Cure at least 48 h [6, 59]

• Cure at least 72 h [42]