In order to prevent the concrete mixer truck from puncture, many people usually use the tire to reduce the tire pressure. Because everyone understands the principle of thermal expansion and contraction, the gas is heated and expanded. If the air pressure in the tire of the mixer is too high, it is easy to puncture the tire if it is heated. Therefore, many drivers will naturally lower the pressure of the mixer tires by 0.1-0.2BAR when the temperature is too high. However, this seemingly sensible method will actually be counterproductive.
Because the interior of the concrete mixer truck has a lot of steel wire to pull the entire tire. When the tire pressure is insufficient, the steel wire inside the tire of the mixer is constantly deformed due to the irregular deformation of the tire. As a result of the continuous deformation of the steel wire, the temperature of the steel wire rises sharply, and the phenomenon of cracking easily occurs. In addition, during the driving process, the temperature of the mixer tire rises, and the possibility of a puncture will increase. Increasing the tire pressure by 0.1 or 0.2 BAR than the normal value can effectively reduce the deformation and breakage of the inner wire of the tire due to the deformation of the tire, thereby reducing the possibility of puncture. Therefore, the tire pressure is not reliable!
Nitrogen gas is also considered a “good” method for summer tires. Since nitrogen is an inert gas, the molecular free travel is larger than oxygen and the permeability in the rubber is low. Therefore, the concrete mixer truck tire pressure drop rate is greatly reduced, maintaining normal tire pressure time increase. At the same time, the volumetric expansion of nitrogen during temperature changes is much lower than that of air containing moisture, thus reducing the chance of puncture.
However, once an experiment was done, nitrogen and air were placed on the left and right tires of the same mixer. Then, the pressure and temperature of the tire are recorded every 10 km. The final result is that the characteristics of “low coefficient of thermal expansion of nitrogen, low thermal conductivity, and slow temperature rise” are not obvious in practical applications. Therefore, it is not advisable to add nitrogen to the mixer tires in the summer to prevent the puncture.
How to prevent concrete mixer truck puncture
1. Replace concrete mixer truck tires in time. High temperature in summer will accelerate the wear and aging of tire rubber, and the strength of the steel layer will decrease. Generally, the concrete mixer truck has a raised mark in the groove of the tire, which is to remind the driver to change the tire in time.
2. Positioning, dynamic balance must be essential. When changing or installing tires and hubs for concrete mixer trucks, the positioning angle and mass distribution will change. The most direct effect is the uneven force of the tires. The individual concrete mixer truck tires have serious tread wear and long-term driving or high speed in summer. It is easy to cause a puncture when driving. The driver must regularly perform four-wheel alignment and dynamic balancing on the concrete mixer truck.
3. Four-wheel shifting, extending the life of the tire. Due to the steering wheel, the front wheel of the concrete mixer truck wears faster than the rear wheel. To extend the service life of the tire, the tires are periodically changed to balance the wear of the front and rear wheels. Generally, the diagonal alignment is adopted to make the tires wear evenly.
4. Maintain normal tire pressure. Summer tire pressure can easily exceed the maximum value. Continuous driving at high temperatures or abnormal leakage will cause tire pressure variation and puncture, so charging concrete mixer truck tires is the right choice. Nitrogen is an inert gas that does not easily change with temperature. In addition, nitrogen gas can also prevent the tire from naturally oxidizing and cracking.
5. Often remove the stone or foreign matter in the tread groove, in order to avoid the concrete mixer truck tire crown deformation. Check the concrete mixer truck tires for flaws, stabs, and cords. If so, it should be replaced in time. In addition, it is often necessary to regularly change the tires when driving on the highway. It is worth noting that the daily concrete mixer truck tire inspection should also include spare tires.
Prevention of concrete mixer truck punctures must start from four aspects
1. Pay attention to the maintenance of the mixer tires on a regular basis, often check the mixer tires for punctures, scratches, protrusions caused by broken wires, change the position or replacement of the vehicle tires as appropriate; tires are generally used for three years or eight or nine Ten thousand kilometers should be replaced.
2. Always check the tire pressure of the mixer to keep it within the standard range. In addition, the nitrogen filling of the mixer tire can keep the tire pressure stable and reduce the chance of puncture.
3. Pay attention to the use temperature of the mixer tires, should not use the method of deflation or splashing water on the tires to heat the tires. This will cause the tire tread and the sidewall rubber layer of the mixer to burst due to uneven shrinkage. When the temperature of the mixer tires rises, the mixer should be parked in a cool place to allow the tires to cool naturally.
4. Avoid using retreaded tires. “When the mixer truck has a flat tire on the expressway, don’t panic.” Shi Shaofeng pointed out, don’t slam on the brakes, hands should fully control the steering wheel, avoid turning sharply, let the mixer along the original Continue driving for a short period of time, then tap the brakes; after the speed is slow, turn to the emergency lane in a light direction; turn on the double flashing light and place the warning sign 150 meters behind the mixer.