Characteristics of the Asphalt Mixture Stability Tester

Characteristics of the Asphalt Mixture Stability Tester:
In view of the shortcomings or deficiencies inherent in the aforementioned prior art, the objective of this utility model is to provide a high-strength Marshall flow value testing setup. This setup utilizes standard Marshall molds, shims, flow value sensors, and a signal switch to perform flow value tests on Marshall specimens ranging from high strength to ultra-high strength. The utility model features a simple and compact design, is easy to operate, and can automatically display the measured flow values of high-strength Marshall stability. With a single-button switch on the display screen of the digital pressure testing machine, the readings for both stability and flow values can be displayed separately, making this setup highly versatile and applicable.

To achieve the above-mentioned objective, this utility model adopts the following technical approach:
An automatic digital-display high-strength Marshall stability and flow value testing apparatus, characterized in that it comprises a digital-display pressure testing machine, two Marshall test molds, shims, a flow value sensor, and a signal switch. Specifically, the two Marshall test molds are positioned directly above the center of gravity of the lower platen of the digital-display pressure testing machine and below the upper platen of the same machine. The two Marshall test molds are nested one above the other to form a cylindrical cavity, and the flow value sensor is mounted on the upper Marshall test mold. The flow value sensor, the digital display screen of the digital-display pressure testing machine, and the hydraulic sensor are each connected to the signal switch. A shim is placed between the upper Marshall test mold and the upper platen of the digital-display pressure testing machine.

Operating Procedures
Special instrument inspections and metrological calibration
After powering on the instrument, turn off the power switch of the control box, press the stop button on the front panel of the instrument housing, and then simultaneously turn on the power switch of the instrument housing. You’ll hear a single “beep,” indicating that the instrument has entered the inspection and calibration procedure. At this point, the pressure and displacement windows should display “000” (if the zero position can be adjusted via the pressure zero-position potentiometer on the rear panel). Once this is confirmed, you can proceed with the displacement calibration.

Displacement calibration
Place the displacement device on a relatively stable workbench, align it with the first scale mark, and push it inward until it reaches the second scale mark. The reading displayed in the flow-value window should change accordingly. After completing the inspection, be sure to turn off the machine and then restart it before proceeding with normal measurements. Note: Under no circumstances should you use the inspection and calibration procedures for routine time or testing purposes. Routine experiments have an over-maintenance function, whereas calibration serves as an additional maintenance function—please pay close attention to this distinction.

Normal experiment
After the power is turned on and the preheating phase is complete, you can start the experiment once you hear the internal buzzer sound. Once the specimen reaches its peak load, the machine will automatically begin lowering. The entire lowering process takes no more than 30 seconds, and the duration of the specimen’s descent can be adjusted using the setting keys. When one specimen’s experiment is completed and both the peak load and displacement values have been locked, the main unit will start descending. After stopping, if you need to print a report or generate a graph, simply press the print key. Be sure to connect the printer beforehand. The system can store parameter data for up to 16 specimens, which can be reviewed using the up and down arrow keys.