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A method of mastic draindown testing was published in 1986 by Kurt Schellenberg and Wolfgang von der Weppen (Schellenberg and Weppen, 1986). Their original method, which consisted of warming up a sample of SMA mix placed in a glass beaker, is summarized in Table 8.1. TABLE 8.1 Parameters of Draindown Testing according to Schellenberg’s Method […]

The draindown effect is the process of the separation of liquid binder or mastic from an SMA mixture that occurs at a high temperature when the binder is still molten. Both the binder and the mastic can separate. It is common knowledge that SMA mixes are marked by an intentional excess of binder, and the […]

An unexpectedly high draindown may be obtained during laboratory tests in which components, including a granulated stabilizer, are mixed with a small mixer (or manually). This may be caused by the way the granulated stabilizer was prepared before mixing it with aggregates. As we know from Chapter 4, the granules contain a small amount of […]

The use of a gyratory compactor is another popular method worldwide for preparing laboratory samples. This piece of equipment is not new; this method of compacting samples was developed in the late 1930s and early 1940s.[48] Making samples with the use of the gyratory compactor is described in EN 12697-31, ASTM D4013-09, and ASTM D3387-83(2003). […]

The procedure of preparing samples using the Marshall method is common. It is currently available in EN 12697-30 and ASTM D 6926-04. The biggest drawback of this method is the incompatibility of laboratory con­ditions and the realism of a construction site. This type of laboratory compaction consists of tamping a mix down with strokes of […]

The components of stone matrix asphalt (SMA) and methods of SMA design have been discussed in the previous chapters of this book. In addition to the basic mix design processes, however, there are additional laboratory tests and procedures that are recommended to supplement the mix design work. Some unique tests focus on special properties of […]

This method, also called the method of iteration, is known chiefly by those who have practiced ready-mix concrete design in a laboratory. It is a laborious procedure because numerous tests need to be conducted (so now it is rarely used). It involves selection of consecutive aggregate fractions so that smaller particles can fit in among […]

The Bailey method was created in the United States in the early 1980s by Robert Bailey of the Illinois Department of Transportation. It enables the selection of an aggregate gradation that guarantees the best interlocking of aggregate particles, a suitable amount of VMA, and proper voids in the final asphalt mix. It was primarily intended […]

In the publication by Brennan et al. (2000) is proposed another method of SMA design developed in Ireland. This method allows for a required discontinuous grada­tion of an asphalt mix between 0.6 mm and 5.0 mm sieves (for SMA 0/14) to create a strong skeleton of coarse grains. The determination of the properties of the […]

7.5.1 Dilation Point Method The dilation point method, which was devised by the American National Center for Asphalt Technology (NCAT) and then adopted in Australia (Stephenson and Bullen, 2002), serves to determine the maximum content of aggregate less than 4.75 mm (i. e., the passive fraction), which still does not cause the dilation of the […]