Views:3 Author:Jane Ching Publish Time: 2021-07-09 Origin:Site
1. Destruction forms and causes of asphalt pavement:
1) Fatigue cracking: The tensile strength is not enough after aging;
2) Low-temperature cracking: Insufficient low-temperature tensile strength and improper porosity
3) Permanent deformation: Insufficient shear strength at high temperature
4) Water damage: improper porosity, poor bonding ability of asphalt and mineral aggregate
2. Asphalt PG classification test:
1. Rotational viscosity test: Measure the temperature during pumping and operation. The viscosity at 135℃ is required to be less than 3Pa.s
2. Rotating film oven test: under the condition of 163℃, rotate at a speed of 15 rpm, while blowing in hot air of 4000ml/min with a nozzle to age the asphalt, rotate for 85 minutes and weigh it.
3. Pressure aging Oven test (PAV): Put the sample that has undergone RTFOT experiment in PAV, aging for 20 hours at a pressure of 2.07MPa and a temperature of 90°C (100 or 110°C) before doing DSR, BBR.
4. Dynamic shear rheological test (DSR)
5. Bending beam rheological test (BBR)
6. Tensile test
3. European CEN standard:
Mandatory indicators: penetration, softening point, flash point, solubility, rotating film oven
Selectivity indicators: wax content, 60°C dynamic viscosity, 135°C kinematic viscosity, breaking point, thin film oven