Library builder

The notion of compactability has been repeatedly used in this text, especially in Chapter 10. Compactability (i. e., susceptibility to compaction) can be defined as the ability of an asphalt mixture to change density under the influence of compactive effort; or to put it another way, compactability is the material feature determined by the amount […]

A fairly comprehensive range of methods and test parameters can be found in publi­cations on SMA fatigue properties. For example, in Australian research (Stephenson and Bullen, 2002) the strain-controlled mode was used to conduct a four-point bend­ing beam test at 20°C, with continuous haversine loading at a frequency of 10 Hz and a range of […]

Fatigue is an effect consistent with the formation of cracks in material caused by a series of repetitive tensile stress cycles that do not exceed the tensile strength of the material. (For more information on fatigue, refer to the many publications with descriptions of this phenomena [e. g., SHRP Reports A-312 or A-404].) 12.3.1 Test […]

A significant impact of mixture type on cracking temperature for newly made mixtures or after a short time of aging has not been observed with TSRST test­ing mixtures of AC, SMA, and porous asphalt (Isacsson et al., 1997). Not until a longer aging period (i. e., more than 25 days) has elapsed has a difference […]

The TSRST method consists of attaching the ends of a specimen (250 mm long and 60 mm in diameter or 50 x 50 mm cross section) to the frame of a device situ­ated in a cooling chamber. The frame is rigid to keep the length of the specimen unchanged. As the temperature falls (at a […]

Reflective cracking is a well-known weak point of semirigid pavements. It advances upward from a rigid base through the asphalt layers. Various techniques for coun­tering reflective cracking (e. g., Stress Absorbing Membrane Interlayer (SAMI) and Stress Absorbing Membranes (SAM) membranes, geogrids) have been used. But their effect usually comes down to more or less effectively […]

Low temperature cracking and reflective cracking will be discussed next. More infor­mation on the theory and origin of cracking can be found in the literature (Arand, 1996; Jacobs et al., 1996; Rigo, 1993). 12.2.1 Low Temperature Cracking Low temperature cracking induced by a drop in temperature has been well-documented (e. g., Fabb, 1973; Isacsson et […]

Rutting resistance is one of the most widely tested properties of asphalt mixes, including SMA, and various methods of testing are conducted all over the world. The impact of side support during creep tests of SMA and AC have been com­pared in Swedish research (Said et al., 2000). Results have explicitly shown the great significance […]

The APA is the second generation of Georgia loaded-wheel tester (GLWT) used in the United States for testing resistance to deformation of asphalt mixtures. The test temperature depends on the climatic data for the region where the mixture will be placed, and it is usually close to the highest expected temperature of the pavement. The […]

A concept similar to side supported creep tests applies to the triaxial dynamic com­pression test. In this method, a specimen is subjected to compression with lateral support. This method has been widely regarded as one of the most accurate, reflect­ing the state of stress in a loaded pavement. Moreover, it enables the measurement of parameters […]