AASHTO T 383:2021 Standard Method of Test for Evaluation of Asphalt Release Agents (ARAs).
This method covers the laboratory performance evaluation of asphalt release agents (ARAs). These ARAs are used for coating metal on truck beds, payers, rollers, slat elevators, and hand tools to prevent asphalt binder or asphalt mixtures from adhering. The ARAs should pcrform this function without causing degradation (stripping) of the asphalt mixture.
The values stated in SI units are to be regarded as standard. Inch-pound units are provided for reference only.
3.1.1. In the Asphalt Stripping Test, a sample of asphalt mixture is soaked in the ARA for seven days alongside a control sample of ARA with no asphalt mixture. Three samples are evaluated at the end of the soak period to determine the degree of stripping that occurred. A visual interpretation to determine discoloration of the liquid is used for comparison purposes. Gravimetric weights are used to determine mass gain or loss.
3.1.2. In the Mixture Slide Test, a sample of asphalt mixture is applied to a metal plate that has been treated with the ARA. The plate is tilted to allow the asphalt mixture to slide free. This process is repeated two more times. The amount of asphalt mixture retained is recorded after the three application cycles. The degree of adhesion to the metal plate is determined by gain in weight.
3.1.3. In the Asphalt Performance Test, hot asphalt binder is poured onto the same treated metal plate used in Section 3.1 .2, allowed to cool, and then pulled away. The amount of retained binder is recorded for each application cycle. This process is repeated, without reapplication of the ARA, until a minimum of 10 percent of the asphalt binder has adhered to the metal plate, or the binder releases 7 times. The degree of adhesion to the metal plate is determined by gain in weight.
3.2. The flash point, infrared spectrum (ATR-FTIR). percent solids, specific gravity, and pH and temperature at the time of the test of the ARA are measured and recorded.
SIGNIFICANCE AND USE
The Asphalt Stripping Test measures the tendency for the ARA to alter the asphalt binder or remove asphalt binder from the asphalt mixture. The agent is evaluated in both its concentrated, non-diluted strength form and at the dilution ratio recommended for use by the manufacturer.
4.2. The Mixture Slide Test simulates a metal truck bed to determine the tendency of the asphalt mixture to adhere to the metal bed when the ARA is used.
4.3. The Asphalt Performance Test measures the tendency for asphalt binder to adhere to metal on truck beds, payers, rollers, slat elevators, or tools when the ARA is used.AASHTO T 383 pdf download.