The water saturation rate of asphalt mixture is crucial to the performance of the pavement, which directly affects its durability and shear strength. The triaxial compression method was used to detect the water saturation rate of asphalt mixture, which could effectively evaluate its water absorption capacity and performance stability. This method not only improves the reliability of the pavement design, but also optimizes the mix ratio, which helps to improve the overall quality and service life of the road. Through scientific testing methods, the quality and safety of road construction are ensured.
Asphalt mixture water saturation test
Purpose and Scope of Application
The water saturation rate test of asphalt mixture is used to determine the water saturation capacity of asphalt mixture, which is mainly used in the mixture quality control of asphalt mixing plant, the investigation of old roads and the quality assessment of pavement compacted asphalt mixture. The test was performed at room temperature to ensure the accuracy of the results.
Technical requirements for instruments and materials
Immersion balance or electronic scale - should be selected according to the maximum weight, the maximum weight is less than 3kg, the inductance is not more than 0.1g, less than 10kg is not more than 0.5g, more than 10kg is not more than 5g.
Vacuum Drying Oven or vacuum dryer – a vacuum level of 97.3 to 98.7 kPa should be maintained and a sink containing the test piece should be accommodated.
Vacuum pump - the power is not less than 200W.
Others - need to be equipped with auxiliary equipment such as sinks, metal plates, metal containers, towels, stopwatches, etc.
Test procedure
1. Make specimens according to standard methods, or use on-site pavement core samples.
2. Weigh the mass of the specimen in air.
3. Soak the specimen in a tank of water at room temperature, and then place it in a vacuum Drying Oven.
4. Start the Vacuum Pump and keep the vacuum Drying Oven at the specified vacuum level for 15 minutes.
5. After releasing the vacuum, let the specimen sit in water for half an hour.
6. Take out the specimen, gently wipe off the surface moisture with a wrung out wet towel, and then weigh the quality of the specimen.
Through the above steps, the water saturation rate of the asphalt mixture can be obtained, and this data can be used to evaluate the water absorption capacity and void conditions of the mixture.
Shear strength test of asphalt mixture (triaxial compression method)
Purpose and Scope of Application
The shear strength test is carried out by measuring the shear strength of the asphalt mixture under the specified temperature and loading conditions by a triaxial Tester to evaluate the high-temperature stability of the asphalt mixture. The standard test temperature is 60°C, but other temperatures can be selected according to requirements.
Technical requirements for instruments and materials
Triaxial Tester - should be equipped with pressure chamber, axial pressure system, confining pressure application system, etc., to meet various test needs.
Oven - adjustable temperature, temperature control accurate to ±1°C of the test temperature.
Rubber film – should be an unaged and non-breathable material.
Test procedure
1. Prepare the specimen, and use the standard molding method to make a cylindrical specimen with a diameter of 100mm and a height of 150mm.
2. Preheat the specimen to keep it at the specified temperature in the oven for 4 to 5 hours.
3. Load the specimen into the rubber film and fix it in the pressure chamber of the triaxial Tester to ensure good sealing.
4. Set the confining pressure and apply the axial load to keep the loading rate constant.
5. When the axial pressure reaches the peak, stop the test, and record the appearance and damage of the specimen.
Through this series of steps, the shear strength of asphalt mixture can be effectively evaluated, providing a scientific basis for pavement construction and maintenance.
conclusion
The water saturation rate and shear strength of asphalt mixture are important indicators to evaluate the performance of asphalt materials. These testing methods not only help to control the quality of asphalt mixture, but also guide the design and maintenance of asphalt pavement in practical projects. Through strict test procedures and standards, the performance stability and reliability of asphalt mixture under different environmental conditions can be ensured.
