AASHTO TP 126-18 pdf free download

AASHTO TP 126-18 pdf free download.Evaluation of the Tracking Resistance of Hot-Poured Asphalt Crack Sealant by Dynamic Shear Rheometer (DSR).
3. TERMINOLOGY
3.1. DefInitions:
3.1 .1. hot-poured asp/ia/i crack sea/ant—Polymer- or rubber-modified asphalt materials most often formulated with mineral filler, used in pavement cracks and joints.
Note 1—Based on the references, hot-poured asphalt crack sealant is typically applied at a temperature of 160°C or above.
3.1.2. creep—Slow deformation under a force.
3.1.3. Jion.’ coeffIcient—Empirical constant C in viscosity units in the Ostwald—DeWeale equation.
3.1 .4. limiting shear viscosity—Low shear viscosity that tends towards the Newtonian viscosity.
3.1.5. Newtonian viscosity—Viscosity independent of the applied stress.
3.1.6. recovery—Elastic recoil after the removal of a stress. See creep.
3.1.7. shear thinning—Reduction in viscosity due to an increase in stress rate.
3.1.8. shear thinning exponent—Exponent P of the Ostwald—DeWeale equation.
4. SUMMARY OF TEST METHOD
4.1. This standard contains the procedure to measure the flow coefficient and the shear-thinning exponent of a hot-poured asphalt crack sealant by means of a dynamic shear rheometer.
4.2. The hot-poured asphalt crack sealant material is placed between two parallel test plates in a dynamic shear rheometer and subjected to eight cycles of creep and recovery at increasing stresses and at a fixed temperature. The limiting shear rate is obtained from the end of the creep phase for each stress level. After the eight cycles, the stresses are plotted against the limiting shear rates and a power-law fit of the data provides two parameters to characterize the asphalt crack sealant flow properties: C, the flow coefficient; and P. the shear thinning exponent.
4.3. Apparent viscosities between 0.1 kPas and 100 kPas are typically obtained between 46°C and
82°C when the applied shear stress varies from 25 Pa to 3200 Pa.
5. SIGNIFICANCE AND USE
5.1. This test is intended for hot-poured asphalt crack sealant applied to roadway joints and cracks.
5.2. The test temperature for this test is related to the average 7-day maximum temperature experienced by the pavement surface in the geographical area for which the hot-poured asphalt crack sealant is intended to be used.
5.3. The asphalt crack sealant flow coefficient and shear thinning exponent are indicators of the resistance of hot-poured asphalt crack sealant to flow out of the crack or joint under loads simulating those from cars and trucks.
5.4. This method is intended for unaged hot-poured asphalt crack sealant, which is relatively soft, but it could be applied to an aged hot-poured asphalt crack sealant that would become softer with age.
6. APPARATUS
6.1. Dynamic Shear Rheo,neter (DSR,)—A DSR system that consists of parallel metal plates, an environmental chamber, a loading device, and a control and data acquisition system. The instrument must meet the requirements stated in T 315.
6.2. Freezer—A calibrated freezer capable of maintaining a temperature of —23°C ± 2°C.
6.3. Specimen Mold—Mold with disk-shaped cavities of sufficient height and diameter to provide duplicate disks 2.0 mm thick and 25 mm in diameter after loading and trimming in the DSR. Note 2—Flexible molds of silicone rubber, used in T 315, with a cavity of about 2.2 mm in height and 19 mm in diameter work well for this purpose, but they could be aluminum, with a bottom plate and two arcs.
7. HAZARDS
7.1. Standard laboratory caution should be used in handling hot-poured asphalt crack sealant according to ASTM D5167.
7.2. This practice does not purport to address all of the safety concerns, if any, associated with their use. It is the responsibility of the user of this standard to establish and follow appropriate health and safety practices and to determine the applicability of regulatory limitations prior to use.AASHTO TP 126-18 pdf download.