During the “Golden Week” holiday in China, in Hezhou, Guangxi, a family of seven was grilling barbecue on a cement ground when suddenly an explosion occurred, causing sparks to shoot up to about 2 meters high, nearly injuring the entire family.
According to reports from mainland Chinese media, on October 2nd, Mr. Li’s family in Hezhou, Guangxi, gathered in the courtyard for a meal. To save time, they did not lay down a barbecue rack or sand while grilling, but instead piled up charcoal and lit a fire directly on the cement ground.
When the charcoal fire was burning halfway, there was a sudden loud “bang” from the ground, and the hard cement ground instantly exploded into a large pit. Rolling hot charcoal, burning red wire mesh, and sharp cement debris accompanied by sparks up to 2 meters high splattered wildly, frightening the family who quickly dispersed in panic.
Mr. Li stated that sparks flew onto his brother’s head, slightly singeing his hair. Fortunately, all seven people managed to evade in time, avoiding serious injuries or disfigurement.
After the shocking video of this incident was exposed online, many internet users questioned: why would seemingly fire-resistant cement ground explode?
In response to this, firefighting experts pointed out that cement (concrete) is a poor conductor of heat, containing a large amount of tiny moisture and enclosed air pores. When the charcoal fire continues to heat up directly, the moisture quickly boils and vaporizes, expanding up to 1700 times its volume. The trapped gas within the enclosed structure cannot escape, leading to a rapid accumulation of pressure. Once it reaches a critical point, the ground explodes like detonating a “landmine”.
Firefighting experts remind that similar accidents have occurred multiple times. When grilling at home, do not let the grill directly contact the cement ground; maintain a certain distance. Lay a layer of sand on the cement ground, then use bricks to support the grill to prevent the cement ground from heating up and posing a danger.