TM 5-822-10/AFM 88-6, Chap. 6
2-2.
Equipment.
The major pieces of equipment required for surface recycling techniques are conventional asphalt distributor for
rejuvenating, heater-planer and motor grader or self-contained heater-planer-paver, broom, trucks, and front-end loader
for heater-planing-overlaying, pavement milling machine, broom, and trucks for cold milling.
2-3.
Rejuvenating.
The application of a chemical rejuvenator provides penetration of a chemical into bituminous pavement which
plasticizes the binder. Rejuvenators can be sprayed directly on the surface of a bituminous pavement, as in figure 2-2, or
they can be used in conjunction with heater-planing-scarifying and cold milling recycling processes.
Figure 2-2. Asphalt distributor applying rejuvenator.
a. Properties of rejuvenators. Some of the properties of rejuvenators are described below.
(1) The application of a rejuvenator to a bituminous pavement partially restores its original asphalt properties.
However, for a rejuvenator to be successful, it must penetrate the pavement surface and soften the asphalt rejuvenator,
the weather conditions, and the permeability of the pavement surface.
(2) When a rejuvenator is applied to a pavement in which the asphalt binder is oxidized, it will retard the loss of
surface fines and reduce the formation of additional cracks. Application of a rejuvenator will also reduce the skid
resistance of the pavement for up to 1 year. While this reduction in skid resistance should not be significant for parking
aprons and taxiways, it may be significant for runways or other areas where high aircraft speeds are likely to occur. Use
caution; be sure to have a full-time person on the job who is experienced in applying rejuvenators.
(3) A rejuvenator should not be applied to a bituminous pavement having an excess of binder on the surface such
as that found in slurry seal, porous friction course, or bituminous surface treatment. When excessive binder is on the
surface, the rejuvenator will soften the binder and cause the surface to become tacky and slick.
(4) The amount of air voids in the bituminous mixture being rejuvenated should be at least 5 percent to ensure
proper penetration of the rejuvenator into the pavement. However, if the voids are less than 5 percent, the rejuvenator may
fill the voids and thus cause an unstable mix.
(5) Care must be used in selecting a rejuvenator. Some rejuvenators perform satisfactorily, but many do not. The
rejuvenator selected for use should have a proven record of satisfactory performance. However, if performance data on
a particular rejuvenator are not available, the rejuvenator should be applied to a test area on the pavement and evaluated
over some period of time to determine its potential performance.
2-2
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