What are the causes of tire blowouts?

Truck-mounted crane driver Master Zhang aptly pointed out that tires are the sole components of a vehicle that are in constant contact with the ground during driving. On the surface, they may seem unremarkable and are often covered in dirt, yet improper maintenance of these seemingly humble parts can be a lurking source of potential accidents.

As the ancients wisely said, “reading ten thousand books and traveling ten thousand miles.” However, for many car owners, this sentiment holds little of the poetic and picturesque charm it might imply. Long-distance travel is not a romantic adventure but a common occurrence and an integral part of their daily lives. One of the most dreaded events during these journeys is a tire blowout.

The service life of tires is often considered a somewhat nebulous concept. In reality, it can vary significantly. Some tires might last for only 50,000 to 60,000 kilometers, while others can endure up to 200,000 kilometers. Truck tires are truly the epitome of hard work and resilience. They are the unsung heroes that endure countless hardships and bear the brunt of various terrains. They can trudge through mountain roads strewn with sand and stones, bravely traverse hard ice surfaces, and even venture through scorching deserts. Yet, even these tough workhorses have their own vulnerable spots – the tire sidewalls.

In daily driving, a staggering 80% of tire problems originate from the tire sidewalls. These scarred and often overlooked areas are not only thinner than the tread but also lack the extensive reinforcement of steel wires found in the tread. As a result, they are relatively fragile and more prone to damage.

At present, in an attempt to load more goods and reap greater economic benefits, many overloaded trucks in China still opt for radial steel-belted tires with inner tubes. To achieve enhanced load-bearing performance, truck owners often inflate these tires with 2 to 4 extra units of air pressure.

When a truck is overloaded and its actual load exceeds the maximum allowable load for the wheels, the internal pressure within the tires begins to rise. As this pressure surpasses the sealing pressure of the tire valve, it can lead to tire leakage. Consider a scenario where a truck with rear dual wheels is overloaded. If one of the tires in the rear dual wheels develops a leak and the driver fails to notice it promptly, the remaining tire in the pair will be forced to bear an excessive load. This overburdened tire is then at a high risk of blowing out.

For example, imagine a truck loaded with heavy cargo, straining under the weight. The tires, already inflated beyond their recommended pressure to handle the extra load, are pushed to their limits. The continuous stress on the tires not only shortens their lifespan but also increases the likelihood of a sudden blowout. This can occur at any time, whether on a busy highway or a remote rural road, posing a significant threat to the safety of the driver, the vehicle, and others on the road.

Prolonged use of the brakes can cause the brake drum to gradually generate high temperatures. In trucks, the tire valve is typically located close to the middle position on the inner side of the tire rim and in very close proximity to the brake drum. The intense heat generated by the brake drum can cause the rubber at the bottom of the valve to expand and deteriorate, leading to a decline in its sealing performance.

Trucks that frequently operate in mountainous and hilly areas are particularly prone to this issue. These vehicles often have to use the brakes for extended periods as they navigate steep inclines and declines. As a result, the sealing performance of their tire valves is generally poor, significantly increasing the probability of tire blowouts.

For instance, a truck climbing a long, winding mountain road must constantly apply the brakes to control its speed. The heat generated by the brakes transfers to the tire valves, gradually weakening their sealing ability. Over time, this can lead to air leakage from the tires, increasing the internal pressure imbalance and raising the risk of a blowout. If the driver is not vigilant and fails to notice the signs of deteriorating tire conditions, a potentially dangerous situation can quickly unfold.

A tire with internal damage, such as one that has been punctured by a sharp object or has a leaking valve and has been repaired, poses a significant risk. The sealing performance and load-carrying capacity of a repaired tire are considerably inferior to those of an undamaged tire.

Typically, at the repair site of the inner tube of a repaired tire, there is a rubber gasket. This gasket is designed to patch the puncture in the outer tire and prevent the repaired area from “bulging” under pressure. However, this protruding gasket on the inner surface of the outer tire can cause wear on the repair site of the inner tube when the vehicle is under load. If the vehicle is frequently overloaded or encounters rough road conditions, the risk of a tire blowout is greatly heightened.

For example, suppose aTruck is carrying a heavy load and hits a pothole in the road. The impact can cause additional stress on the already weakened repair site of a damaged tire. The rubber gasket may not be able to withstand the increased pressure and friction, leading to a potential blowout. This not only endangers the driver and the vehicle but can also cause damage to other vehicles and property in the vicinity.

After continuous high-speed driving for an extended period, tires generate heat. If this heat is not dissipated in a timely manner and the tire temperature continues to rise, excessive heating (exceeding 95°C) can cause the tire to delaminate and eventually burst.

Using cold water to cool hot tires is a common but extremely dangerous practice. The sudden change in temperature from hot to cold can cause the tire to contract rapidly, leading to structural damage and increasing the risk of a blowout.

For instance, a driver who has been driving at high speed for a long time decides to cool the tires with cold water. The rapid temperature change can cause the tire’s internal structure to weaken, potentially resulting in a blowout when the vehicle resumes driving. This can be a catastrophic event, especially if it occurs at high speeds or in heavy traffic.

In vehicles with rear dual axles and semi-trailer models, due to the large number of tires, it can be challenging to immediately detect a tire blowout. If the vehicle continues to be driven after a tire blowout, the damaged tire will rub against the intact tires, generating heat. Eventually, this friction can cause another tire to blow out as well.

After a dual-tire blowout, the wheel hub comes into contact with the ground, generating a large amount of sparks. These sparks can then ignite the damaged tire, leading to a potentially explosive situation.

For example, a semi-trailer truck experiences a tire blowout on one of its rear wheels. The driver, unaware of the severity of the situation, continues to drive. The damaged tire rubs against the adjacent tires, causing them to heat up. As the heat builds up, another tire blows out. The wheel hub now scrapes along the ground, creating sparks that can set the damaged tires on fire. This not only poses a direct threat to the vehicle and its cargo but can also spread fire to nearby objects and cause a major accident.

In conclusion, understanding the causes of tire blowouts is crucial for truck drivers and vehicle owners. By being vigilant about overloading, monitoring tire pressure and temperature, promptly addressing damaged tires, avoiding improper cooling methods, and replacing damaged tires in a timely manner, they can significantly reduce the risk of tire blowouts and ensure safer journeys. Regular maintenance and inspection of tires are essential to detect potential problems early on and take preventive measures to avoid dangerous situations on the road.