What is the function of bridge Expansion joint? How to maintain it?

In order to meet the requirements of deck deformation, Expansion joint are usually set between two beam ends, between beam ends and abutments, or at the hinge position of the bridge. The Expansion joint is required to be flexible, firm and reliable in two directions parallel to and perpendicular to the bridge axis, and the vehicle shall be stable without sudden jump and noise when driving; It should be able to prevent the infiltration and blockage of rainwater and garbage; Installation, inspection, maintenance, and removal of dirt should be simple and convenient. When setting Expansion joint, the railing shall be disconnected from the deck pavement. Generally speaking, the bridge Expansion joint is mainly used to prevent the pavement structure from Thermal expansion due to temperature changes. In order to reduce earthquake disasters, Expansion joint also play a role in preventing excessive displacement of beams. In short, it is a device for buffering displacement.

2023-06-27

What are the characteristics of the bridge Expansion joint and how to maintain it

The damage of the bridge expansion joint not only affects the driving comfort, but also causes damage to other components, bringing hidden dangers to the safety of the bridge. The rubber strip of the Expansion joint is damaged, the debris on the road falls into the Expansion joint, and the Expansion joint cannot expand freely. When the temperature changes, it will compress the beam head or platform back, and compress the beam head or platform back. Therefore, maintenance measures should be taken.

2023-06-27

Oil resistant rubber plate testing, how is it different from ordinary plates

The use conditions of rubber sheets are very relaxed, and they can be used for a long time both indoors and outdoors. Rubber sheets can produce many special properties and applications, which are important factors for the development of the rubber sheet industry (such as highly insulated rubber sheets, anti-static rubber sheets, high-temperature rubber flooring, oil resistance, acid and alkali resistance, etc.). So, today we will introduce the characteristics of oil resistant rubber plate inspection and distinguish it from ordinary rubber to help you better understand. Rubber products come into long-term contact with oil media during use, and oil can penetrate into the interior of the rubber, causing expansion, thereby reducing the strength and other mechanical properties of the rubber. Oil can dissolve rubber because after oil penetrates the rubber, molecules diffuse and the network structure of vulcanized rubber changes. According to the oil resistance of rubber and the polarity of rubber and oil, rubber molecules contain polar groups (such as bromine, ester, bromine, chlorine atoms, etc.), and rubber can display polarity. When rubber with high polarity comes into contact with non polar petroleum oils, the polarity difference between the two is significant, and rubber is not prone to expansion. It has good oil resistance to non-polar oils such as Nitrile rubber, hydrogenated Nitrile rubber, acrylic rubber, chlorohydrin rubber, chlorosulfonated polyethylene rubber, fluororubber, fluorosilicone, etc.

2023-06-27

Scope of application and precautions for externally attached waterstops

External waterstop, also known as back attached waterstop or external waterstop, is a type of waterstop structure installed on the outer side (upstream) of concrete deformation and settlement joints in underground structures. It has the ability to adapt to the expansion and deformation of concrete based on the material elasticity and structural form of the waterstop. Externally attached waterstops are suitable for waterproofing deformation joints in underground structures, dams, water storage tanks, swimming pools, roofs, and other building materials and structures. The selection of external waterstops can be based on the following aspects: consideration should be given to the corrosive effects of contact media (such as acids, alkalis, salts, oils, solvents, and various corrosive gases) on external waterstops. When there are weak acid and weak alkali corrosive media, Neoprene waterstop shall be selected. In case of oil corrosive medium, Nitrile rubber waterstop shall be used. If there is a possibility of mold erosion, the mold resistance of the external waterproof tape should be considered, and its level should reach level 2 or above. The selection of external waterstop materials should consider the influence of usage conditions, such as temperature, UV and ozone aging, repeated deformation, and other factors. EPDM rubber waterstop shall be used at low temperature.

2022-07-28

Construction method of external sealing strip

During the construction process of external waterstop, it is important to understand that a 30mm thick wooden template should be set on the back of the waterstop. The width and length of the template should meet the requirements for installing the waterstop. The wooden formwork should be connected to the overall formwork of the exterior wall to prevent displacement, slurry leakage, and water loss during the concrete pouring process. At this point, it is also recommended to use 212-inch (lin=25mm) double cap nails to fix the external rubber waterstop to the wooden template, and nail the double cap nails on the edges of both sides of the waterstop, with one double cap nail every 200mm. Therefore, some installed waterstops should be flat and not sagging. After pouring concrete, the strength of this part can reach over 80% of the design strength, and the formwork above it can be removed. However, with the strict requirements for engineering quality, externally attached waterstops have gradually received attention. Externally attached waterstops can be divided into externally attached rubber waterstops and externally attached plastic waterstops based on their material. The external sealing strip can be divided into EP middle non perforated external sealing strip and EB middle perforated external sealing strip according to the construction site.

2022-01-10

Is the price of Expansion joint in Hebei high? What is the main function of Expansion joint

Is the price of Expansion joint in Hebei high? What is the difference between Expansion joint and settlement joint: Expansion joint, also called temperature joint, is a joint set to prevent deformation caused by temperature. The Expansion joint shall start from the top of the foundation and be disconnected from the wall, floor and roof. The foundation is buried underground and is less affected by temperature, so it does not need to be disconnected. If the roof of the building adopts tile roof, Expansion joint is not required for the roof. The spacing of Expansion joint is closely related to the material, structure type, construction method, location and environment of the component.

2021-11-12

How long does the rubber bearing need to be replaced

In fact, when we discover abnormal deformation of the rubber bearing, we need to quickly stop replacing it. This situation is mainly due to the lack of leveling during the construction process, which leads to significant initial shear deformation of the bearing and the inability to guarantee its function. So at this point, we need to quickly stop and replace it to ensure that the rubber bearings play their due role and prevent hidden dangers.

2021-11-12

What should be paid attention to during the construction of rubber bearings

When checking the rotation angle of rubber bearings, it is necessary to consider the impact of uncertainty in the compressive elastic modulus and take the upper limit of the compressive elastic modulus for calculation. We also need to consider temperature factors together to advance the rolling function of the rubber bearing itself. In terms of construction, strictly follow the specifications and level the upper and lower load-bearing steel plates. If there are no upper and lower load-bearing steel plates, the top surface of the pad stones supported by the pier and abutment should be leveled, and the relative level difference of each pad stone should be controlled within 1mm.

2021-11-12

Changfeng Alliance Internet Information Service Industry Promotion Working Group

Technological innovation is the key to core competitiveness. China Digital has built a strong information technology research and operation team, with nearly 2000 software research and development personnel. It is the chairman unit of the "Changfeng Alliance Internet Information Service Industry Promotion Working Group" of the Ministry of Science and Technology, truly proposing a SaaS service system with Chinese characteristics, with SPS as the core to build standards and norms suitable for China's IT service operation. In terms of ICT infrastructure construction, China Digital has established professional data centers in Beijing, Guangzhou, Suzhou, and other places, achieving interconnection between North and South Telecom, and building a highly secure and reliable network environment with over 3000 operational equipment; By establishing joint laboratories with companies such as NetApp and HP, computing pooling and storage pooling have been achieved; In the field of e-commerce, we have pioneered the development of an on-demand and personalized e-commerce platform. We have applied for more than ten technical patents and become a pilot enterprise for patent engines in Beijing.

2021-11-09

Building standards and norms suitable for IT service operations in China with SPS as the core

Technological innovation is the key to core competitiveness. China Digital has built a strong information technology research and operation team, with nearly 2000 software research and development personnel. It is the chairman unit of the "Changfeng Alliance Internet Information Service Industry Promotion Working Group" of the Ministry of Science and Technology, truly proposing a SaaS service system with Chinese characteristics, with SPS as the core to build standards and norms suitable for China's IT service operation. In terms of ICT infrastructure construction, China Digital has established professional data centers in Beijing, Guangzhou, Suzhou, and other places, achieving interconnection between North and South Telecom, and building a highly secure and reliable network environment with over 3000 operational equipment; By establishing joint laboratories with companies such as NetApp and HP, computing pooling and storage pooling have been achieved; In the field of e-commerce, we have pioneered the development of an on-demand and personalized e-commerce platform. We have applied for more than ten technical patents and become a pilot enterprise for patent engines in Beijing.

2021-11-09