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Laborer/Craft Worker

Any individual who works as part of a paving crew or performs localized operations at a production facility. Activities include concrete finishing and asphalt handwork, and ranges from general labor to work that requires specialized training or certification.
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General Guidance

  This is an informational resource on hot mix asphalt (HMA). It contains a general overview of all HMA aspects. It is intended to assist those who work with HMA in any way including architects, engineers, contractors, students, and homeowners. Pavement Checklist Pavement Distress Top-Down Cracking References Suggested Reading Asphalt Institute. (2001[1]). HMA Construction. Manual … Read more »


Construction Noise

Noise Basics Healthy humans can hear audible sound with a range of 20 Hz to 20,000 Hz with a maximum intensity at 3,000 Hz. (Hz = Hertz, or cycles per second.) Frequencies below 20 Hz are called “infrasound” and above 20,000 Hz “ultrasound.” The numerical magnitude of a sound typically expressed as sound pressure level … Read more »

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HMA Placement Considerations

There are, of course, many considerations to take into account when placing HMA. Many are dependent upon local materials, weather, crew knowledge and training, and individual experience. This subsection presents a few of the basic considerations that apply in virtually all situations: Lift thickness. A “lift” refers to a layer of pavement as placed by … Read more »

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HMA Placement

Mix placement and compaction are the two most important elements in HMA pavement construction. Mix placement involves any equipment or procedures used to place the delivered HMA on the desired surface at the desired thickness. Mix placement can involve complicated asphalt paver operations or simple manual shoveling. This section provides a basic description of HMA … Read more »

Figure 12: Cutting equipment for one dowel bar slot at a time.

Dowel Bar Retrofit Construction Practices

Introduction The following describes and illustrates the dowel bar retrofit construction process. In addition, descriptions of critical details for ensuring pavement performance are also included. In general, the dowel bar retrofit process includes the following steps: Using diamond saw blades, sawcut dowel bar slots (three to four per wheelpath). Remove existing concrete within dowel bar … Read more »

Figure 2. Side tie bar inserter.

Tie Bar Placement

Tie bars are typically placed after PCC placement either by hand or using a tie bar inserter attachment (slipform paving only). When one lane at a time is paved, tie bars are inserted at mid-slab depth and bent back until the adjacent lane is ready to be paved (see Figure 1). On slipform pavers, tie … Read more »

Figure 7. Joints sealed with hot-pour liquid sealant on a freeway on-ramp (normally, joints should coincide with lane divisions as they do near the horizon of this photograph).

PCC Joint Construction

Location Typical joint locations are covered in the article on Joints, and are not repeated here. However, it is important to note that joint locations should be indicated on the construction plans and planned in advance (Figure 1). Intersection joint locations can be quite complex and should be marked out on the base in advance … Read more »

Figure 8: Notched wedge joint.

Longitudinal Joint Construction

A longitudinal joint is the interface between two adjacent and parallel HMA mats.  Improperly constructed longitudinal joints can cause premature deterioration of multilane HMA pavements in the form of cracking and raveling (Figures 1 and 2).  These distresses, caused by relatively low density (high air voids) and surface irregularity at the joints, can largely be … Read more »

A pneumatic tire roller compacting chip seal.

Paving Equipment

Stabilizers/Reclaimers A stabilizer/reclaimer is a vehicle with a dual purpose. These machines have a large rotor blade which may be used to cut and pulverize damaged or old pavement, but which also may be used to mix lime, fly ash, or cement into the subbase in order to stabilize poor soils. Milling Machines A top … Read more »

Figure 2: HMA Placement


Mix laydown involves everything used to place the delivered HMA on the desired surface at the desired thickness. The asphalt paver is the principal machine involved in mix laydown and is assisted by the material transfer vehicle (MTV) in some instances. Placement Considerations There are, of course, many considerations to take into account when placing … Read more »

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