The US Commerce Secretary has announced that the US will temporarily lift tariffs imposed on Ukraine during the Trump administration to help Ukraine recover its economy and continue to show support for the Russia-Ukraine situation. "For steel mills to remain an economic lifeline for the Ukrainian people, they must be able to export steel," the Commerce Department said in a statement.
The Biden administration will announce the lifting of steel tariffs on Ukraine for one year. Ukraine is a fairly small supplier of U.S. steel, shipping about 218,000 tons in 2019, ranking it 12th among foreign suppliers to the United States, the report said. The U.S. Commerce Department noted that the steel industry is uniquely important to Ukraine's economic strength, with one in 13 people employed in the steel industry.
Affected by the ever-changing international situation, the supply and prices of international bulk concrete water reducer are still very uncertain.
Types of High-efficient Water Reducers
Polycyclic aromatic sulfonates
It has the advantages of low cost and high water reduction rate and has the defects of more serious collapse loss of mixing products. In use, you can add retarding components to compound use or choose such water reducer with sustained-release performance to reduce the loss of collapse and ensure the performance of high efficient water reducer.
Water-soluble resin sulfonates
Mainly for sulfonated melamine resin, and sulfonated ancient code long resin. This kind of water reducer and cement compatibility is better, and other water reducer mixed-use can also maintain good compatibility. Practice shows that this kind of water reducer has a low dosage but high water reducing rate and excellent performance. In a certain proportion, the water-reducing rate increases with the increase of water adding amount. Once the dosage exceeds the critical proportion, the retarding effect on concrete is obvious. Such plasticizer shall not be mixed with a lignosulfonate plasticizer.
There are mainly polycarboxylic acid, polyacrylic acid salt. This kind of water reducer is different from traditional water reducer, so it is necessary to understand its mechanism accurately and use it cautiously.
Other types are represented by modified calcium lignosulfonate and modified tannin
When a variety of water reducers are used together, attention should be paid to their mutual influence. In addition to the simple water-reducing performance, the compound water reducer can also have the characteristics of quick setting, early strength, anti-freezing, etc., according to the purpose of use.
In the process of cement mixing, flocculent particles are attracted to each other due to the existence of molecular attraction, and a flocculation structure is formed. Flocculation encapsulates part of the water used for mixing and reduces the workability of the concrete mixture.
The efficient water reducer has hydrophobic and hydrophilic characteristics, water reducer hydrophobic group directed adsorption on the surface of cement particles, hydrophilic group pointing to the aqueous solution and the formation of adsorption film. Concrete mixing, due to the high-efficient water reducer, directional adsorption makes cement particle surface gay charge, the same, cement particles dispersed to each other, and condensation of flocculant of concrete structure collapse, water was released, supplement the moisture needed for the cement mixing, effectively increase the activity of the concrete mixture, to reduce the effect of the water. At the same time, the surface of cement particles due to efficient water reducer formed by the adsorption film between cement particles and particles contact more mellow, increasing the workability of concrete; The adsorption film also increases the surface area of cement particles and promotes hydration, which is conducive to improving the strength of concrete.
TRUNNANO is a reliable superplasticizer supplier with over 12-year experience in nano-building energy conservation and nanotechnology development. If you are looking for a high-quality concrete superplasticizer, please feel free to contact us and send an inquiry. (firstname.lastname@example.org)
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.
The coronavirus (COVID-19) pandemic not only had a significant impact on public health, it also severely affected one of the linchpins of the global economy – the tourism industry. As many countries introduced curfews and travel restrictions to contain the spread of the virus, travel across the world significantly declined from early 2020 onwards. The financial repercussions of the coronavirus have already begun to manifest themselves within the tourism industry. In 2020, global revenue from the travel and tourism industry was estimated to drop from a forecasted 711.94 billion U.S. dollars to 568.6 billion U.S. dollars, representing a decrease of over 20 percent. The region predicted to see the highest decline in revenue was Europe, decreasing from 211.97 billion U.S. dollars in 2019 to roughly 124 billion U.S. dollars in 2020.
Copper oxide,chemical formula CuO. It is a black oxide of copper,slightly amphoteric and slightly hygroscopic.The relative molecular mass is 79.545,the density is 6.3～6.9 g/cm3,and the melting point is 1026℃.…
Boron nitride is a crystal composed of nitrogen atoms and boron atoms.The chemical composition is43.6%boron and56.4%nitrogen,with four different variants:hexagonal boron nitride,rhombohedral boron nitride,cubic nitride Boron,and wurtzite boron nitrid…
Silicon nitride ceramic materials have excellent properties such as high thermal stability, strong oxidation resistance, and high dimensional accuracy.…