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2.3.1 General Principles The Czech method has been employed in the Czech Republic based on the Czech guidelines TP 109. The distinctive feature of this method is the consideration of the influence of the coarse aggregate content on asphalt mixture properties. Some knowledge of the impact of coarse particle quantity in creating an SMA aggregate […]

After the selection of an optimum aggregate mix, the amount of binder should be selected in such a manner that the desired content of air voids in a compacted SMA TABLE 7.1 Requirements for a Laboratory-Compacted SMA Binder Mixture Using a Marshall Hammer or superpave Gyratory compactora property requirement Notes Minimum content of binder, >6.0 […]

An optimum variant should be selected out of the three defined trial design grada­tion curves. The selection criteria of the optimal gradation curve should consist of the smallest amount of coarse aggregate combined with the following two conditions at the same time: • VCAMIX is lower than VCAdrc or the VCA ratio (VCAmix/VCAdrc) is less […]

So far, we have carried out a series of tests. Let us sum up all the data at our disposal as follows: • Air voids in the compacted coarse aggregate VCAdrc • Initial (or adjusted if needed) content of binder We have also made a series of compacted SMA samples. Now it is time to […]

The minimum content of binder in an SMA has been fixed at 6.0% (m/m), but a slightly higher quantity of binder in a mixture is advised. This is intended to provide protection from exceeding the lower production limit when producing the SMA. To begin, an initial trial quantity of binder in mixtures should be adopted […]

The dry-rodded method has been standardized in AASHTO T 19-00, where its thor­ough description has been included. It is recommended to perform two tests per sample and use the average value. The following gives a short outline of the equip­ment used and the modus operandi. The equipment needed includes a balance, a steel tamping rod […]

The Americans have undertaken analyses on the usefulness of various methods of testing for contact between coarse particles. Ultimately, they have settled on the dry — rodded test according to AASHTO T 19-00 (Brown and Haddock, 1997). It has also been standardized as ASTM C29-97. Let us remember what we are considering now; we are […]

This method emerged in 1990 after a tour of Europe when some U. S. engineers learned of the benefits of SMA. A series of research efforts started soon after to develop a method of designing SMA. This resulted, among other things, in publica­tions (Brown and Haddock, 1997; Brown and Mallick, 1994) that tried to reach […]

The volumetric relationship in an asphalt mixture is shown schematically in Figure 7.1 in German terms. Equations are based on TP A-08 2007 and Hutschenreuther and Woerner (2000). Symbols in Figure 7.1 include the following: Hbit = Volume of voids in compacted asphalt samples, % (v/v) Bv = Binder volume, % (v/v) Mv = Mineral […]

The basic and universal rules of stone matrix asphalt (SMA) design were described in the previous chapter. Chapter 7 provides an overview of SMA design methods devel­oped in various countries. Undoubtedly, there are many of them, so their description could be the subject of a separate book. We will focus here on the most distinctive […]