This equipment is used to test the depth to which hot-applied joint/crack sealant is pressed into a cone under specified conditions; this is known as cone penetration.

Road surface heated sealant cone penetration tester

Model:LJLMJ-1

I. Product Introduction

The LJLMJ-1 type road surface heated sealant cone penetration tester is designed and manufactured according to the technical requirements of JT/T 740-2015 "Road Surface Heated Sealants". It is a specialized cone penetration testing device used to evaluate the consistency and workability of hot-applied sealants. This instrument also references the internationally recognized ASTM D5329-20 "Test Methods for Hot-Applied Sealants" and ASTM D6690-21 "Specifications for Hot-Applied Joint Sealants for Concrete and Asphalt Pavements", maintaining consistency with international standards in structural design, testing operation, and measurement accuracy. During the test, the sample is heated to 25℃ under specified conditions. A cone with a specified mass and angle is placed on the sample surface and released freely, allowing it to penetrate the sealant within 5 seconds. The depth of cone penetration is measured to characterize the material's hardness and consistency. Cone penetration is expressed in units of 0.1 mm; for example, a cone penetration depth of 30.0 mm corresponds to a cone penetration of 300. This equipment can accurately reflect the workability of hot-applied road sealant and is compatible with domestic and international standards, making it an ideal instrument for road engineering material testing and quality control.

II. Performance Characteristics

1. The instrument allows testing in different directions, and can even be used in a constant temperature water bath.

2. Digital display depth measurement mechanism, easy to use, with good repeatability and high measurement accuracy.

3. The support movement has two speeds: fast and micro-motion, facilitating accurate alignment of the needle tip with the sample surface during testing.

4. Equipped with a platform leveling mechanism for easy adjustment.

5. Includes a manual release mechanism for the needle insertion device, ensuring normal operation even when the automatic release time control is not in use.

IV. Test Procedure

1. Pour the sealant, having reached the required penetration temperature, into the sample dish. The specimen height should exceed the expected cone penetration value by 10 mm, ensuring no air bubbles are present. After preparation, cool the specimen at room temperature (15°C–30°C) for 1.5–2 hours, then transfer it to a constant-temperature water bath (25°C ± 0.5°C) for 1.5–2 hours.

2. Adjust the cone penetration meter to ensure it is level. Inspect the connecting rod and guide rail to confirm the absence of water, foreign matter, and significant friction.

3. Remove the sample dish that has reached the required temperature and place it on the tripod in a flat-bottomed glass dish. Do not fill the glass dish with water.

4. Place the flat-bottomed glass dish containing the specimen... On the platform of the cone penetration tester, slowly lower the connecting rod. Observe using a reflector or light at an appropriate position until the tip of the standard cone just contacts the surface of the specimen. Secure the connecting rod with the button, pull down the toothed rod until it contacts the top of the connecting rod, and adjust the dial pointer to zero.

5. Press the button firmly with your hand and start the stopwatch simultaneously. The standard cone will fall freely. When the standard cone has penetrated for 5 seconds, stop pressing the button to secure the standard cone connecting rod. Pull down the toothed rod until it contacts the end of the connecting rod, and record the cone penetration depth (0.1 mm).

6. Note: When using an automatic penetration meter, the timing starts simultaneously with the standard cone falling into the specimen and stops automatically after 5 seconds.

V. Test Result Report

1. For the same specimen, conduct three parallel tests. The distance between measuring points should not be less than 25 mm, and the distance from the measuring point to the edge of the specimen should not be less than 13 mm.

2. If the difference between one of the measured values from the three parallel tests on the same specimen and the average value meets the repeatability test accuracy requirements, the average value shall be taken as the cone penetration test result.

3. The difference between one of the measured values from the three parallel tests on the same specimen and the average value should not exceed 15% of the average value.