In this paper, the elastic recovery test and the evaluation method of anti-spalling agent performance of asphalt are introduced. The elastic recovery test is designed to evaluate the recovery performance of thermoplastic rubber-modified asphalt, while the anti-spalling agent performance evaluation focuses on the adhesion and water stability of asphalt to aggregate. Through standardized testing, the stability and durability of asphalt in different environments are ensured.
The asphalt elastic recovery test is designed to evaluate the elastic recovery performance of thermoplastic rubber polymer modified asphalt, which is mainly used to determine the percentage of deformation that asphalt can recover after a certain length is elongated in the ductility test. This method is especially suitable for the detection of SBS and SB polymer modified asphalt, and is often used to judge the flexibility of asphalt materials in pavement engineering.
Mold test - the test mold used in the ductility test is adopted, but the middle part is replaced by a straight side mold, and the cross-sectional area of the specimen is 1 cm².
Water tank - can maintain the specified test temperature, the error does not exceed 0.1 °C. The volume of the sink is not less than 10L, and the depth meets the immersion requirements of the specimen.
Ductility testing machine - related equipment for the same ductility test.
Scissors – used to cut specimens during tests.
Thermometer – for sink temperature monitoring.
1. Make asphalt specimens and keep them warm in a 25°C sink for 1.5 hours.
2. Stretch the specimen to 10 cm at a rate of 5 cm/min and then stop stretching.
3. Immediately cut the specimen and keep it in water for 1 hour, during which time maintain a constant temperature.
4. After removing the specimen, measure its retracted residual length to calculate the elastic recovery rate.
The elastic recovery rate is calculated according to the standard formula, and the level of the recovery rate reflects the elastic properties of the asphalt material.
The purpose of this test was to evaluate the adhesion of asphalt to aggregate after the addition of anti-spalling agent, as well as the water stability of its asphalt mixture. The performance evaluation of asphalt anti-spalling agent is of great significance to ensure the long-term combination of asphalt and aggregate in pavement engineering, especially when acid aggregate (such as granite, sandstone, etc.) is used.
Asphalt heating equipment – used for heating, mixing asphalt and anti-spalling agent.
Marshall Test Equipment – for determining the water stability of asphalt mixtures after the addition of anti-spalling agents.
Aggregate - the acid aggregate used in the actual project.
1. Heat and filter the asphalt, mix the anti-spalling agent in proportion, and stir well.
2. The thin film heating test is used to heat and age the asphalt mixed with anti-spalling agent.
3. The adhesion between asphalt mixed with anti-spalling agent and coarse aggregate was tested by water immersion method or boiling method.
4. The asphalt mixture after short-term and long-term aging treatment was subjected to water immersion Marshall test and freeze-thaw splitting test to evaluate the water stability.
5. If necessary, the asphalt mixture test without aging treatment is carried out to evaluate the heat resistance of the anti-spalling agent.
The elastic recovery properties and anti-spalling properties of asphalt are directly related to the long-term use effect and durability of the road. The elastic recovery test can effectively evaluate the flexibility of polymer-modified asphalt, while the performance evaluation test of anti-spalling agent can ensure the water stability of asphalt mixture. In order to meet the needs of highways and other demanding projects, standardized testing methods must be used to ensure that asphalt and its modifiers can perform well in practical applications.