Because the weldability of old steel is very poor, welding is generally not used for reinforcement repair of old steel bridges. Riveting appeared in the 1920s and has since evolved into a dominant form of steel structure connection. The rivet connection generally has the characteristics of good toughness and plasticity, uniform and reliable transmission force, easy connection quality inspection, and low quality requirements for the main material. However, there are many lap joints, the nail holes weaken the rods, the holes in the construction process and the riveting cost, and the technical tools are required to have a higher technical level. For the above reasons, the form of riveting has rarely been used now. The working principle of the refined bolt and the greased bolt is basically the same, and both can be used for the reinforcement repair of the old structure, and can also be used for the construction of the new structure. Old structural reinforcement repair 1) The surface friction coefficient of the riveted structure is generally very low. Since riveting requires specialized equipment and personnel, riveting is now rarely used. There are currently thousands of riveted old steel bridges in use around the world. There are more than 12,000 railway steel bridges in China, and more than 10,000 riveted steel bridges are in service. Grease-loading bolts are a good way to solve the repair of riveted old steel bridges. It does not require special handling of the original surface, such as sand blasting. 2) The screw hole required for the grease-filled bolt is not high, and can be 23mm larger than the nominal diameter of the screw. 3) If the plate thickness and the screw diameter can maintain an appropriate ratio, the grease-providing bolt will provide higher resistance than the replaced one. rivet. 4) Eliminate internal corrosion. Since the resin is completely filled with voids, it can completely eliminate internal corrosion (also important for new structures). 5) Due to the gap between the corroded steel plate and the reinforced steel plate, the amount of resin will greatly exceed that of filling only the gap between the screw and the hole wall. the amount. However, this also completely ruled out the possibility of the steel plate continuing to corrode. Mens Work Shirts,Construction Safety Shirts,Safety Work Shirt,Worker Shirts Xinxiang Worldbest Patron Saint Co., Ltd , https://www.xxhyhsworkwear.com