Asphalt emulsification is the process of dispersing the oil phase in the aqueous phase to form a stable emulsion, and the type and concentration of the emulsifier and the external environmental conditions have a significant impact on its stability. Methods to evaluate the storage stability of emulsified bitumen include storage performance testing, separation tests and particle size analysis, through which the stability performance of emulsion bitumen can be effectively judged in long-term storage and application.
This test is used to evaluate the storage stability of different types of emulsified bitumen and is usually performed at room temperature for 5 days (1 day in special cases) after emulsion preparation. Through this test, it is possible to understand whether the emulsified asphalt has problems such as stratification, sedimentation or discoloration during storage, and then judge its long-term reliability.
It mainly includes asphalt emulsion stability test tubes made of glass, sample containers, electric furnaces or electric Hot Plates, precision balances, filter screens with 1.18mm mesh holes, etc. These devices ensure the precision of the experimental process and the accuracy of the results.
First, clean and dry the stability test tube to ensure that it is clean and dry.
The emulsified asphalt specimen passed through the 1.18mm filter was slowly injected into the test tube and allowed to stand for 5 days.
Observe and record whether the emulsified asphalt has delamination, and according to the sampling of the lower and upper branches, weigh and measure the content of evaporation residues, and calculate its storage stability.
The temperature range of the emulsified asphalt during storage and the difference in the content of evaporation residues in the samples should be recorded in detail in the report, and the storage stability of the emulsified asphalt should be finally concluded.
This test is specifically designed to test the stability of emulsified bitumen at low temperatures. By subjecting the asphalt sample to a low-temperature freeze-thaw cycle, the change of its physical state was observed, so as to determine its applicability in the low-temperature construction environment.
This experiment requires a 250 mL Erlenmeyer flask, a refrigerator (set to -5°C), a Thermostatic Water Bath, a 1.18 mm strainer, and a balance of equipment. These devices ensure that experiments are completed at low temperatures and at constant temperatures.
Load the emulsified bitumen sample into an Erlenmeyer flask and place it tightly sealed in the refrigerator and keep it at a low temperature for 30 minutes.
Then quickly transfer to a constant temperature sink at 25 °C for 10 minutes.
After repeating the freeze-thaw cycle twice, the sample was taken out for observation and filtered through a 1.18mm sieve to record whether there was coarse particulate matter or agglomeration.
The test results should clearly indicate whether the emulsified asphalt has coarse particles or agglomeration after the freeze-thaw cycle, so as to judge its low-temperature storage stability.
The test mainly evaluates the compatibility of non-ionic slow-cracking emulsified asphalt with cement, and determines the construction performance of its comprehensive stable material. This is particularly important for the combination of emulsified asphalt and cement in pavement construction.
This test involves the use of a standard sieve, a mixing vessel, a metal stir bar, and a 100 mL graduated cylinder. All utensils are strictly cleaned and dried before use to ensure the accuracy of the experiment.
Adjust the experimental environment and the temperature of all materials to 25°C.
Weigh 50g of ordinary Portland cement and pour the same quality of emulsified asphalt into the mixing vessel.
During the mixing process, the mixing state of cement and emulsified asphalt is closely observed, and finally the state change of the mixture is recorded by screening.
The report should indicate the mixing of cement and emulsified asphalt, including whether there are any significant changes in physical properties, and give an evaluation of suitability.
Through the above detailed testing methods, the performance of emulsified asphalt can be comprehensively evaluated from multiple perspectives such as storage stability, low temperature stability and mixing performance with cement. These tests are of great guiding significance for selecting the appropriate type of emulsified asphalt in the construction process.