The Asphalt Enguela viscosity test is a method used to determine the viscosity of emulsified asphalt and coal pitch in accordance with T 0622-1993. The test uses an Engela viscometer to calculate the Engela degree (E) at 25°C by recording the time it takes for the specimen to flow out of 50 mL. This method can effectively evaluate the fluidity of asphalt materials, and is widely used in road engineering and material quality control, which provides an important basis for the performance analysis of asphalt.
The Engela viscosity test of asphalt is mainly used to determine the viscosity of emulsified asphalt and coal asphalt, and is tested by Engualla viscometer. This method is suitable for industrial and laboratory environments to ensure the flow of bitumen at different temperatures and its performance in practical applications. The standard test temperature is 25°C, and the Engela degree (E) is obtained by measuring the outflow time, which provides a quantitative basis for the physical properties of the asphalt material.
instrument
Engela viscometer – should comply with GB266 standard.
Main components
Specimen Container – Brass with polished and gold-plated inner wall and spherical bottom with three indicators to control specimen height. The outflow orifice should be equipped with a small platinum tube.
Outer container – for heat preservation and internal agitator to ensure uniform temperature.
Tripod – adjustable to maintain the stability of the viscometer.
Thermometer – can measure the range of 0-30°C or 0-100°C with an accuracy of 1.0°C.
Acceptance bottle – wide-mouth glass bottle with a volume of 200mL with graduation.
Other materials
Xylene, ethanol (95%), filter (pore size 1.18mm), wash, gasoline, etc.
Tools such as stopwatches, pipettes (5mL), etc.
Methods and Steps:
Preparation
Cleaning the instrument – Wash the viscometer's inner chamber and outflow tube bore with xylene and distilled water, dry and place on a tripod.
Wash the receiving bottle – wash it with petrol, lotion and water in turn, then dry it at 105°C.
Filter the sample – The emulsified bitumen specimen is filtered through a 1.18mm screen.
Determination of water value – Determination of the water value (t) of a viscometer using distilled water.
Two methods
The outflow time of 50 mL of distilled water is directly determined at 25 °C.
The 200 mL outflow time was determined at 20 °C and multiplied by the conversion factor F (0.224).
Test procedure
Injection of the specimen – Inject a bitumen sample preheated to just over 2°C into the inner chamber, ensuring that the liquid level is above the indicator tip.
Adjust the temperature – heat the water in the outer container to just over 25°C and keep the temperature difference between the inner and outer container no more than ±0.2°C.
Outflow time determination
When the sample reaches 25 °C and is held for 2 min, quickly remove the cork.
Start the stopwatch and record the time it takes to get 50mL out of the stream to the nearest 0.1 second.
compute
The Enguela viscosity of the specimen can be calculated using the formula (T0622-1), which is calculated using the ratio of the outflow time to the water value.
Reporting & Allowable Errors
At least two parallel trials should be reported, and if the difference between the two results does not exceed 4% of the mean, the average of the two results should be taken as the test results.
The allowable error for repeatability tests is 4% of the mean and for reproducibility tests is 6% of the mean.
conclusion
The Engela viscosity test provides important data support for the characterization of asphalt materials. Through the quantitative analysis of the fluidity of asphalt, its applicability and performance in engineering applications can be effectively evaluated, and a scientific basis can be provided for the quality control and standard formulation of asphalt materials. This method is widely used in the world, especially in the study of emulsified asphalt and coal asphalt, and has important reference value.
summary
The Enguela viscosity test of asphalt is an important method for evaluating the fluidity of emulsified asphalt and coal asphalt and is carried out according to the T 0622-1993 standard. The Engela degree (E) is calculated by measuring the time required for the specimen to flow out of 50 mL at 25°C by an Engualla viscometer, which reflects the viscosity characteristics of the asphalt. This test not only provides a scientific basis for the quality control of asphalt, but also promotes the in-depth study of the properties of asphalt materials, which is widely used in road engineering and construction. With the continuous development of asphalt technology, the application prospect of this method will become more and more important.
