AASHTO R 95-19 pdf free download

AASHTO R 95-19 pdf free download.Accelerated Aging of Hot-Poured Asphalt Crack Sealant Using a Vacuum Oven.
呢面料3. TERMINOLOGY 3.1. De/Inition: 3.1.1. hot-poured asphalt crack sealant—polymer- or rubber-modified asphalt binder most often formulated with a mineral filler. Note I —Based on the references, hot-poured asphalt crack sealant is typically applied at a temperature of 160°C or above. 4. 4.1. SUMMARY OF PRACTICE hot-poured asphalt crack sealant material is placed in a stainless steel pan and aged at 115°C for 16 h under a vacuum of 75.9 cmHg. 5. SIGNIFICANCE AND USE 5.1. This standard practice is designed to simulate the aging and weathering of hot-poured asphalt crack sealant. 5.2. Hot-poured asphalt crack sealant material aged with this standard practice is best used to evaluate sub-zero characteristics. 5.3. For hot-poured asphalt crack sealant materials with different asphalt binder sources, polymer grades, and filler types and content, there is no unique correlation between the accelerated conditions and the time of in-service weathering. The accelerated aging leads to hot-poured asphalt crack sealant rheology typical of sealants weathered I to 10 years in the field. 5.4. Hot-poured asphalt crack sealant must be rernixed before being aged by this standard practice. 6. APPARATUS 6.1. Vacuum Oven—Oven with a vacuum valve, a bleed valve, and a pressure gauge in centimeters of mercury (cmHg). The oven must be capable of maintaining a vacuum of 75.9 ± 2 cmHg and a uniform temperature of 115 ± 1°C. Refer to ASTM El 45 to verify temperature uniformity. The oven should be of a size sufficient to accommodate a minimum of eight sample pans of 6 in. diameter on two shelves. 6.2. Vacuum Pump—A one- or two-stage mechanical pump capable of achieving a vacuum of 99.9 percent or better in 10 mm or less. (See Note 2.) Note 2—At sea level, the achievable vacuum is 76 cmHg. See the Appendix for the effect of elevation on the achievable vacuum reading. 6.3. Laboratory Oven—Calibrated Type hA oven specified in ASTM E145. This oven can produce and maintain a temperature of 180 ± 0.5°C. 6.4. Stainless Steel Pans—Pans of sufficient 7. HAZARDS 7.1. Standard laboratory caution should be used in handling and remixing hot-poured asphalt crack sealant in accordance with ASTM D5 167. 8. VERIFICATION AND STANDARDIZATION 8.1. Temperature and vacuum control of the ovens should be verified and standardized according to the standard recommended practices for establishing and implementing a quality management system for construction materials testing laboratories (AASHTO R 18) or each user’s quality assurance program. 8.2. Temperature Detector—Verify the calibration of the temperature-sensing device to 0.1°C every 6 months in accordance with ASTM E77 for liquid-in-glass thermometers. 8.3. Vacuum Gauge—Standarize the vacuum gauge to an accuracy of 1 percent every 6 months. 8.4. Verify that the sought temperature is obtained within I h after the application of vacuum. An example is shown in Figure 1.
9. PREPARATION 9.1. Apply vacuum and preheat the vacuum oven to 115士1°C. This typically takes 2 to4 h. 9.2. Preheat the laboratory oven to 180 土5°C. 9.3. Melt and homogenize 400 to 500 g of hot- poured asphalt crack sealant material following the procedures outlined in ASTM D5 167 specified for solid materials. Pour 35土0.5 g of hot material into a stainless steel pan. (See Note 4.) Note 4- Homogenization should be done at the manufacturer’s recommended heating temperature for 1 hr 土10 minutes. Note 5- At the same time, samples can be poured for other tests, including the viscosity test (T 366), the low-temperature tests (T 368 and T 369), and the adhesion test (T 370).AASHTO R 95-19 pdf download.