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The United States is one of the few countries where requirements for cellulose fibers and mineral stabilizing agents have been standardized. Some other countries have adopted the U. S. requirements in their own specifications. The requirements for cellulose and mineral fiber SMA stabilizers after AASHTO MP-8-05 include the following: [22] • Shot (nonfibrous material) content […]

Specifying the desired properties of stabilizers is a troublesome task, which is why there are not very many examples of formalized requirements for them. In fact, detailed testing of a stabilizer’s properties is practically impossible in the asphalt plant laboratory. Therefore, in many countries, testing is limited to draindown check­ing (i. e., only an empirical […]

The requirements for SMA binders used in the United States are related to the Superpave system prevailing in the country. The basis for the selection of binders for wearing courses, in principle their functional type (performance grade [PG]), is the climate of the given area of application. So all binders have to meet the same […]

In Europe, road binders (paving grade) according to EN 12591 and modified binders according to EN 14023 have been used in SMA mixtures. Normally, road binders of 50/70 and 70/100 are used; however softer 160/220 types have also been cited in the regulations for roads with light traffic. The properties of each type of paving […]

SMA mixtures are chiefly laid as wearing courses. Binders for them should therefore have suitable properties for asphalt mixtures applied to that layer. The majority of SMAs are placed in moderate climates. Therefore the SMA binder is usually an unmodified binder, or sometimes a polymer-modified one, with a penetration between 50 and 100 (0.1 mm) […]

U. S. requirements for aggregates constitute a compromise between high quality con­ditions and the necessity of taking into account the economics of manufacturing asphalt mixtures. The number of properties specified are limited, while the require­ments themselves are somewhat broad (see Table 5.5), compared with the European standards. The requirements also vary from state to state. […]

In the Comite Europeen de Normalisation, or European Committee for Standardi­zation (CEN), the member states’ requirements for aggregates designed for asphalt mixtures have been unified in the EN 13043 standard entitled Aggregates for Bituminous Mixtures and Surface Treatments for Roads, Airfields, and Other Trafficked Areas. It provides a set of aggregate properties and a series […]

A distinctive feature of stone matrix asphalt (SMA) components is their high quality. In this chapter we shall have a look at the requirements for those materials in various countries. Comparing them may be interesting because of the diversity of emphases different countries place on individual conditions. Consequently, the following components will be subsequently discussed […]

Various methods for testing the tendency for binder to draindown in a particular SMA are presented in Chapter 8. The original Schellenberg’s method and other techniques according to AASHTO and EN 12697-18 standards are also described there. In most countries, Schellenberg’s or a similar method for determining the quantity of stabilizer in a mix has […]

Almost every working road laboratory has conducted many series of draindown tests. The results of companion tests on a wide variety of stabilizers are seldom published. However, the following interesting conclusions can be drawn from large — scale research conducted in the United States (Brown and Mallick, 1994): • SMA binder draindown was seen to […]