Mechanical Spreaders Spreader boxes that are mounted on wheels. The spreaders are attached to and pushed by dump trucks (HMA boxes are pulled and chip spreaders are pushed).

Medium-Curing (MC) Asphalt Cutback asphalt composed of asphalt cement and a diluent of medium volatility.

Mesh The square opening of a sieve.

Micro-Surfacing A mixture of polymer modified asphalt emulsion, crushed dense graded aggregate, mineral filler, additives and water. It provides a thin resurfacing of 10 to 20 mm (3/8 to 3/4 inch) to the pavement.

Milling Machine A self-propelled unit having a cutting head equipped with carbide-tipped tools for the pulverization and removal of layers of asphalt materials from pavements.

Mineral Dust The portion of the fine aggregate passing the 0.075 mm (No. 200) sieve.

Mineral Filler A finely divided mineral product, at least 70 percent of which will pass a 0.075 mm (No. 200) sieve. Pulverized limestone is the most commonly manufactured filler, although other stone dust, hydrated lime, portland cement, and certain natural deposits of finely divided mineral matter are also used.

Modified Asphalt Rubber - Asphalt Concrete (MAR-AC) High quality, thoroughly controlled hot mixture of modified asphalt rubber binder (AR) and well-graded, high quality aggregate, which can be thoroughly compacted into a uniformly dense mass.

Modified Asphalt Rubber Binder (MAR) Conventional asphalt cement to which recycled ground tire rubber and compounds have been added, that when reacted with the hot asphalt cement causes a dispersion of the tire rubber particles and compounds.

Multiple Surface Treatment Two or more surface treatments placed one on the other. The aggregate maximum size of each successive treatment is usually one-half the previous one. A multiple surface treatment may be a series of single treatments that produces a pavement course up to 25mm (1 in.) or more in thickness. A multiple surface treatment is a denser wearing and waterproofing course than a single surface treatment.

Natural (Native) Asphalt Asphalt occurring in nature, which has been derived from petroleum through natural processes of evaporation of volatile fractions, leaving the asphalt fractions. The native asphalt of most importance is found in the Trinidad and Bermudez Lake deposits. Asphalt from these sources is often called lake asphalt.

Nondestructive Testing (NDT) In the context of pavement evaluation, NDT is deflection testing, without destruction to the pavement, to determine a pavement's response to pavement loading.

Open-Graded Aggregate One containing less-fine aggregate in which the void spaces in the compacted aggregate are relatively large and interconnected, usually 10% more.

Open-Graded Asphalt Friction Course A pavement surface course that consists of a high-void, asphalt plant mix that permits rapid drainage of rainwater through the course and out the shoulder. The mixture is characterized by a large percentage of one-sized coarse aggregate. This course prevents tires from hydroplaning and provides a skid-resistant pavement surface with significant noise reduction.

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