The U.S. and its allies plan to impose sanctions on more Russian industries and supply chains.
The US government representatives recently visited Europe to consult with allies on strengthening and enforcing sanctions to punish Russia. They also plan to take action to disrupt their critical supply chains.
The US government claims that the sanctions imposed on Russia since the invasion began on February 24 have proved extremely effective, plunging Russia into a financial crisis. The sanctions include a freeze on the Russian central bank's foreign exchange assets, a ban on hard currency transactions by major Russian banks and wealthy individuals, and export restrictions on advanced semiconductors and other technologies. The sanctions have weakened the Russian economy and left the Kremlin with fewer resources.
The volatile international political situations will continue to affect the markets and prices of many commodities like the Prestressed Concrete.
What is Prestressed Concrete?
Prestressed Concrete is a kind of concrete component mainly used in construction engineering and bridge engineering.
To avoid premature cracks in reinforced concrete structures, make full use of high-strength steel bars and high-strength Concrete, and try to reduce the tensile stress generated by the components by applying external forces before the concrete structures or components are subject to the service load, even in a state of compressive stress. Concrete elements are below.
How Prestressed Concrete Works
The pre-compression stress is used to reduce or offset the tensile stress of Concrete caused by the load, to control the tensile stress of the structural components to a small range, even in a compressed state, to delay the appearance and development of concrete cracks, thereby improving the resistance of the components. Crack performance and stiffness.
Advantages of Prestressed Concrete
1. Good crack resistance and high rigidity. Due to the prestressing of the components, the appearance of cracks is significantly delayed. Under the action of the load, the components may not appear to crack, or the cracks may be delayed, so the stiffness of the components is improved, and the durability of the structure is increased.
2. Save materials and reduce self-weight. Because its structure must use high-strength materials, it can reduce the number of steel bars and the section size of components, save steel and Concrete, and reduce the self-weight of the structure, which has obvious advantages for large-span heavy-load structures.
3. It can reduce the vertical shear force and primary tensile stress of concrete beams. The curved reinforcement (bundle) of the prestressed concrete beam can reduce the vertical shear force near the support in the beam. Because of the existence of prestress on the concrete section, the principal tensile stress under the load is also reduced. This is beneficial to reduce the web thickness of the beam so that the self-weight of the prestressed concrete beam can be further reduced.
4. Improve the stability of compression components. When the compression member is relatively long and slender, it is easy to be bent after receiving a certain pressure, resulting in loss of stability and destruction. If prestressing is applied to the reinforced concrete column so that the longitudinally stressed steel bars are tensioned very tightly, not only the prestressed steel bars themselves are not easy to bend, but they also can help the surrounding Concrete to improve the ability to resist bending.
5. Improve the fatigue resistance of components. Because the rebar with strong prestress has relatively small changes in stress caused by loading or unloading during the use stage. It can improve fatigue strength, which is very beneficial for structures that bear dynamic loads.
6. Prestress can be used as a means of connecting structural components to promote the development of new systems and construction methods for large-span structures
Some requirements for prestressed steel bars:
(1) The strength should be high. The tensile stress of prestressed steel bars will cause various stress losses during the entire fabrication and use of components. The sum of these losses can sometimes reach more than 200N/mm² if the strength of the steel bar used is not high, the stress established during tension will even be lost.
(2) It must have good adhesion with Concrete. Especially in the pretensioning method, there must be a high bond self-anchoring strength between the prestressed steel bar and the Concrete. For some high-strength smooth steel wire, it is necessary to go through "scoring," "pressure wave," or "kink" so that it can form scored steel wire, corrugated steel wire, and kinked steel wire to increase the bonding force.
(3) There must be sufficient plasticity and good processing properties. The higher the strength of the steel, the lower its plasticity. When the plasticity of the steel bar is too low, especially under low temperature and impact loading conditions, a brittle fracture may occur. Good workability means that the welding performance is good. When the upsetting head anchor plate is used, the upsetting of the steel bar head does not affect the original mechanical properties, etc.
TRUNNANO is a concrete additives supplier with over 12 years experience in nano-building energy conservation and nanotechnology development. We accept payment via Credit Card, T/T, West Union and Paypal. Trunnano will ship the goods to customers overseas through FedEx, DHL, by air, or by sea.
If you are looking for high quality concrete additives, please feel free to contact us and send an inquiry.
A preparation developed in China; the comfort and the multifunctional properties of nanomaterials make "dead skin" capable of sensing again. Electronic skin is artificial skin that mimics the function of human skin. Recently, the world-renowned journal Advanced Science reported a simple and highly programmable electronic skin on a leather substrate developed by a Chinese team, which combines the natural complex structure of leather, the comfort of wearing, and the multi-functional properties of nanomaterials. , so that the "dead skin" has the ability to sense again.
In the future, Prestressed Concrete will be used in various high-tech fields, and the market demand for Prestressed Concrete will also be great. Please contact us for more information on Prestressed Concrete.
Roche and its subsidiary TIB Molbiol have developed a series of tests for the detection of the monkeypox virus, the Switzerland-based pharmaceutical company announced. The monkeypox virus is a close relative of the smallpox virus, belonging to orthp…
Early strength agent is an admixture which accelerates the development of concrete early strength and has no significant effect on later strength.…
Boron carbide (B4C) is an extremely hard boron-carbon ceramic and covalent material used in tank armor, bulletproof vests, engine damage powder, and many industrial applications.…