Every year there is a period of frequent fires, among which fire accidents caused by circuits in the home occur from time to time. In addition, heating equipment is used more in winter. If the heating equipment is short-circuited, it is easy to cause a fire and become out of control. Residents should do a good job of replacing the aging circuit, do not leave the heating equipment (electric blanket, oil heater, bath heater, etc.) in a long-term standby state, and should not go out without turning off the heating equipment, otherwise it will easily cause accidents. Once a fire occurs, the building structure must be inspected.

Many people don't understand why building reinforcement must be carried out after a fire. Below, HORSE will tell you why building reinforcement must be carried out after a fire. Most of the houses nowadays are made of concrete. Concrete is an artificial stone made by hardening cement as a cementing material, thickened aggregate (stone), fine aggregate (sand), admixtures, admixtures, etc. Its mechanism under the action of fire can be summarized into the following three aspects:

First, the surface temperature rises faster than the inside of the fire place, and the temperature difference between the inside and the outside causes the concrete to crack;

Second, the cement stone is decomposed by heat, which destroys the cohesive force of the colloid, cracks, hairy surface, sand, honeycomb, cracks, and corners collapse and fall off;

Third, the thermal incompatibility between the aggregate and the cement stone, the cement stone is stretched, and the aggregate is compressed, resulting in stress concentration and the development of micro-cracks.

Therefore, after a fire, the concrete will become very fragile. If it is not reinforced, it is likely to cause accidents such as collapse. According to the degree of damage caused by the fire, fire damage can be divided into mild damage, moderate damage, severe damage, and chemical damage. Slight damage: surface damage in a local area, edge peeling and cracks. Moderate damage: There is no plastic deformation of structural components, but there is severe section damage and reduction in the strength of steel bars. Serious damage in the scope of a single building component and structure: the load-bearing component partly or completely loses its function, but does not collapse. Chemical damage: The most important situation at present is the erosion of the concrete structure by the combustion gas of PVC.

After the fire is detected, the repair and reinforcement are divided into the repair and reinforcement of damaged components, and the repair and reinforcement of the structure. The principle of reinforcement of damaged components is that the design should be simple and easy to implement, safe, reliable, economical and reasonable; attention should be paid to the node structure and construction method of the reinforced component, to ensure that the reinforced part works with the original structure and consider the impact of the reinforcement on the overall stress change of the building .

The principle of structural reinforcement is to remove damaged concrete and add steel bars when necessary to ensure that the structural components have full bearing capacity. Recover the cross-section with the corresponding concrete according to the required size, and the reinforcement can be replaced, wire-wound, bonded steel, and bonded fiberglass. For minor damage that does not affect the load-bearing capacity of structural components, just remove the loose concrete part and fill it to make the concrete surface to ensure that the steel bars are not corroded. Serious damage should be dealt with individually according to the site conditions, often requiring partial reinforcement or dismantling for reconstruction.

Therefore, after a building has a fire, the building structure must be inspected. Determine the degree of damage to the building structure based on the test results, determine whether it needs simple repair or dismantling and reconstruction, after the fire, the building structure must be tested and then reinforced.