1. Periodic anticorrosion treatment
Generally speaking, the design life of steel structure is 50 years, and the probability of damage caused by overloading is very small. Most of the damage of steel structure is caused by the reduction of mechanical and physical properties of structure caused by corrosion. The Code for Design of Steel Structures has certain requirements for corrosion protection of steel structure which has been used for more than 25 years. Therefore, it is required that the external coating protection of the steel structure should meet the use requirements of the steel structure. Generally, the steel structure needs three years of maintenance (cleaning up dust, rust and other dirt in the steel structure before brushing the paint). The types and specifications of paints should be the same as those of the original coatings. Otherwise, the incompatibility of the two coatings will bring more harm. Users should maintain and maintain regularly and planned.
2. Periodic fire prevention treatment
The temperature resistance of steel is poor, and many of its properties change with the temperature. When the temperature reaches 430-540 C, the yield point, tensile strength and elastic modulus of steel will decrease sharply and lose the bearing capacity. The steel structure must be maintained with refractories. No fire retardant paint or fire retardant paint was used before. The fire resistance of buildings depends on the fire resistance of building components. When a fire occurs, its carrying capacity should last for a certain period of time, so that people can safely evacuate, rescue materials and extinguish and extinguish fire.
Fire-proof measures are as follows: therefore, exposed steel components are brushed with fire-proof paint. Specific requirements are: fire-resistant time of steel beams is 1.5h, and fire-resistant time of steel columns is 2.5h, so that it meets the requirements of building codes.
3. Periodic monitoring
The failure of steel structure caused by rust is not only the reduction of effective section, but also the "rust pit" on the surface of the component. The former reduces the bearing capacity of members, leading to the decline of the overall bearing capacity of steel structures, especially for thin-walled steel and light steel structures. The latter causes the phenomenon of "stress concentration" in steel structure. When the steel structure is subjected to impact load or alternating load, brittle fracture may occur suddenly. However, when this phenomenon occurs, there is no sign of deformation and it is not easy to detect and prevent in advance. Therefore, it is very important to monitor the stress, deformation and crack of steel structures and main components.