HOT MIX ASPHALT, HMA, PAVEMENT 401.01 Description This work shall consist of one or more courses of QC/QA HMA base, intermediate, or surface mixtures constructed on prepared foundations in accordance with 105.03. 401.02 Quality Control 10 The HMA shall be supplied from a certified HMA plant in accordance with
Apr 16, 2014 · The grade of asphalt binder selected typically is the same as incorporated into the HMA mix. For most areas, the asphalt binder tack coat material would meet the requirements of a performance Hot Mix Asphalt (HMA) is a combination of aggregate and asphalt binder mixed at an elevated temperature to form a hard, strong pavement construction material. HMA allows mixes to be designed in the laboratory at four different levels (50, 75, 100, and 125 gyrations) simulating four different 20-year traffic levels in the field. Asphalt treated base (ATB) is a dense-graded HMA with a wide gradation band and lower asphalt content intended for use as a stabilizing base course. ATB costs less than typical HMA mixes because it can be produced with less expensive aggregates and lower percentages of asphalt binder. The first recycled HMA project was constructed in 1976 on a 4-lane urban highway, in which the original pavement was recycled and replaced with a 175-mm (6.9-in) recycled HMA base, a 40 mm (1.6-in) recycled HMA binder and a 20-mm (¾-in) surface wearing course. The recycled HMA contained 50 percent RAP material.
Non-wearing course is typically the bituminous mixture below the wearing course or driving surface. Non-wear mixtures include base, level and binder courses. In Superpave (Gyrarory) design, non-wearing course is defined as mixture below the top four inches of pavement.
– Type III Binder Course – Type 6 Top Course – 2200 tons of HMA in an 8 hour operation – 1200 tons of heated silo capacity.
The full Superpave QC/QA (new certification) course lasts five days, the Superpave QC/QA re-certification course runs for two days, and the HMA Aggregate Consensus Tests, TSR, and Binder Ignition Oven courses are one day long. The Superpave QC/QA courses are divided into modules as shown below.
– Type III Binder Course – Type 6 Top Course – 2200 tons of HMA in an 8 hour operation – 1200 tons of heated silo capacity. 4 Chart 1: Recommended Mixes for Normal HMA Applications (Proposed compaction levels based on NCHRP 9-9 levels @ 4% Per Voids) Low Volume Design Level Recommended Aggregate Size Binder Type Compaction Level Compacted Thickness Pavement Course: Main Line: Shoulder: SuperPave HMA Surface Course: 50 mm (2 inch) 50 mm (2 inch) SuperPave HMA Binder Course: 465 mm (18.25 inch) 150 mm (6 inch) Subbase Granular Material, Type C : 310 mm (12.25 inch) Pipe Underdrains: 100 mm (4 inch) Aggregate Shoulder Wedge, Type B : Lime Modified Subgrade: 305 mm (12 inch) 305 mm(12 inch