Qingdao structural reinforcementReinforcementIntroduction
Structural reinforcement refers to engineering measures to repair the structural damage of aging and damaged buildings in the irrigation area, restore or improve their bearing capacity. For buildings in areas with severe aging damage and insufficient structural safety, after diagnosis and evaluation, if the structure can be repaired due to structural damage, structural reinforcement measures should be taken as soon as possible to repair and use in time
Structural reinforcement plan
Qingdao structural reinforcementReinforcement can be carried out according to the following procedures:
① Through reliability appraisal, the location and form of aging damage and its influence on structural reliability are determined, which provides a basis for structural reinforcement.
② Choose a suitable reinforcement plan.
③ Rebar design and construction organization design. Including structural and component bearing capacity checking calculations, reinforcement design and construction drawings.
④ Organize construction. Structural reinforcement is mostly carried out under load or partial load. It is advisable to remove part of the load during construction and increase support to ensure construction safety.
Qingdao structural reinforcementReinforcement principle
Structural reinforcement should follow the following principles:
① The principle of overall effect. During and after reinforcement, the load effect should be within the allowable range of the overall resistance effect of the building.
② Principle of strength value. It is not allowed to mix fly ash, pozzolan or blast furnace fluid into reinforced concrete. Its strength should be one level higher than that of the original structural concrete. The bonding degree of the bonding material and grouting material used for reinforcement should be higher than the tensile and shear strength of the bonded concrete.
③ Principle of load value. The actual effective section should be adopted, the strength design value of the additional material should be appropriately reduced, and the degree of matching of the reinforcement part with the original structure and various possible additional stresses should be considered.
Reinforcement method of hydraulic structure
There are many ways to strengthen hydraulic structures, including:
① Add section method. It can improve the bearing capacity and section stiffness of the structure, and change the natural frequency of the structure, but it will increase the weight of the structure and occupy a certain space.
② Ladle method. Without increasing the cross-sectional size of the component, the bearing capacity, rigidity and ductility of the component are improved, but the cost of reinforcement and maintenance is higher.
③ External bonding method. The use of epoxy resin to bond the steel plate to the tensile surface of the component or increase its shear strength has the advantages of outsourcing steel and saving investment.
④ Prestress method. Using external prestressed steel tie rods to reinforce the structure is an economical and effective method that basically does not change the use space of the structure, but can improve the bearing capacity of the components. The negative bending moment generated by the prestress can offset part of the load bending moment, reduce the deflection of the component, and even close the cracks. However, prestressing facilities are required.
⑤ Improved the stress system method. By adding components or fulcrums, the internal force of the components is reduced and the bearing capacity of the structure is improved.
⑥ Grouting method. In order to improve the durability of concrete components, cement and chemical materials are added to the cracks of the concrete components, and the function of the components is restored through pressurizing equipment