The Asphalt Mixture Theoretical Maximum Specific Gravity Tester is used to determine the maximum specific gravity (Gmm) of asphalt mixtures in a fully air-free condition. It removes entrapped air from the sample using a vacuum method and calculates the maximum density of the mixture, providing essential data for asphalt mix design, air voids calculation, and compaction quality evaluation in laboratory and field applications.

Asphalt Mixture Gmm Tester

Model:TD711-1

I. Product Introduction:

This instrument was developed and manufactured by Hebei Tianqixingzi Inspection Equipment Co., Ltd. in accordance with the requirements of the Ministry of Transport of the People's Republic of China's industry standard JTG 3410-2025, 《Standard Test Methods of Asphalt and Asphalt Mixture for Highway Engineering》(T0709-2025). It is utilized to determine the theoretical maximum specific gravity of asphalt mixtures using the vacuum method, serving purposes such as asphalt mixture mix design, road condition surveys, pavement construction quality control, and the calculation of air voids, compaction degree, and related parameters.

II. Technical Parameters:

1. Power Supply Voltage: 220V ±10%, 50Hz; Input Power: 150W

2. Negative Pressure Range: 0–100 kPa

3. Operating Mode: Automatic / Manual

4. Container Volume: 4300 mL × 2 units

5. Overall Dimensions: 500 × 500 × 360 mm

6. Vibration Mode: Continuous Vibration

7. Vacuum Pump Power: 160W

8. Vibrator Power: 30W

III. Operating Instructions:

To accommodate the requirements of various tests—and in accordance with established testing protocols—the instrument features two primary modes of operation: a programmable automatic test mode and an independent manual control mode. This instrument is capable of simultaneously testing multiple parallel specimens.

Automatic Test Operating Instructions:

Connect the power supply (220V/50Hz) and press the power switch; the display window will begin counting seconds, indicating that the unit is ready for testing.

Place the negative-pressure vessels (hereinafter referred to as "material cylinders")—along with the water and test specimens contained therein—onto the vibrating table, and securely fasten the lids on both material cylinders.

Pressing the "Auto" button initiates the instrument's automatic operation. In accordance with the instrument's preset program, the unit will first evacuate the chamber for 2 minutes; the vacuum gauge pointer will indicate that the vacuum level within the material cylinder has reached 96.3 kPa, while the pressure display window shows 3.7 kPa. Subsequently, the vibrating platform will oscillate continuously for 15 minutes; concurrently, the vacuum pump will continue to operate to maintain the material cylinder's vacuum level at 96.3 kPa.

At the 17-minute mark of the automated test sequence, the instrument automatically ceases operation—specifically, it automatically vents the chamber. At this point, insert the material cylinder lid into the handles located on either side, remove the material cylinder, and switch off the power supply.

If, following the automated programmed test, residual gas remains within the specimen, the operator may utilize the manual control function to allow the instrument to continue operation. First, press the "Evacuate" button, followed by the "Vibrate" button; the instrument will then simultaneously evacuate the chamber and vibrate the material cylinder. During this process, the "Stop" button may be pressed at any time to halt the operation.

Manual Control Test Operation Instructions:

1. When the "Vibration" and "Vacuum" functions are to be performed simultaneously, press the "Vacuum" button first; once the vacuum level inside the material cylinder reaches 96.3 kPa, then press the "Vibration" button to initiate the oscillation action.

2. After pressing the "Vacuum" button, the maximum continuous operating duration for the vacuum pump is 17 minutes; after pressing the "Vibration" button, the maximum continuous operating duration for the vibrating table is 15 minutes.

IV. Precautions:

1. Upon startup of the vacuum pump, a distinct "snap" sound may be heard from within the unit. This is a normal sound resulting from the release of air through the pump's protective nozzle; users need not be concerned.

2. The vacuum pump must not be operated continuously in an open-channel mode (drawing directly from the atmosphere) for more than 3 minutes. If, after starting the vacuum pump, the needle on the vacuum gauge remains stationary or oscillates in place without moving, this indicates a poor seal on the material hopper or an air leak in the piping. The operator should apply slight manual pressure to press down firmly around the perimeter of the hopper; once the gauge needle resumes normal movement, the pressure may be released.

3. Upon completion of the experiment, the material cylinder must be cleaned immediately. Furthermore, any water traces on the cylinder, the lid, the vibrating platform, and all other parts of the instrument must be wiped dry.

4. After unpacking, install the instrument on a level surface in a dry, well-ventilated, and clean environment. The ambient temperature must not exceed 40°C.

5. After the instrument has operated continuously for two hours, it must be shut down for one hour.

6. Under no circumstances should water from the container be allowed to drip into the instrument.

7.Unauthorized personnel—specifically, anyone other than professional technical staff from the manufacturer—are strictly prohibited from removing the protective panels covering any part of the instrument. Any damage to the instrument resulting from such unauthorized actions shall be the sole responsibility of the violator.

V. Packing List

Main unit: 1 set.

Vacuum containers: 2 pcs, specification 4300 mL.

Fuse: 1 pc, specification 15 A.

Instruction manual: 1 copy.

Certificate of conformity: 1 copy.