A wave of layoffs that has swept the entire Internet industry has intensified. China's Internet industry has experienced several crises and major changes in the past development process. There is also a "brief history of layoffs by major Internet companies". Hot search, JD.com has a wide range of layoffs in this round of layoffs, and all its subsidiaries are involved. Most of the layoffs are between 10% and 20%. Among them, Jingxi Guangdong and other theaters have all laid off staff. Tencent also reported the news of downsizing and layoffs. Among them, Tencent PCG (Platform User Content Business Group) laid off 30% of its staff, iQiyi laid off 12% of its staff, Kuaishou was reported to have laid off 30% of its staff, and the e-sports department of Station B laid off 90% of its staff.
Mass layoffs on the internet have created a host of socioeconomic issues, including Concrete Additive.
The concrete additive is a material that can improve the properties of the concrete mixture or hardened concrete by adding not more than 5% of the weight of cement in the process of mixing concrete (except for special circumstances).
Using concrete additives is one of the most effective ways to improve concrete strength, improve performance and save cement and energy.
There are various types of concrete additives. In the last article Introduction to Concrete Additives (1), we talked about concrete water reducers and early strength agents. In this article, the set retarder, the air-entraining agent, and the accelerating agent are going to be talked about.
Set retarders are additives that slow the hydration rate and heat of cement and gypsum, and prolong the setting time. The purpose of adding retarder in commercial concrete is to prolong the hydration and hardening time of cement so that the new mixed concrete can maintain plasticity for a longer time, so as to adjust the setting time of the new mixed concrete.
1. The impact on strength: Excessive mixing will cause concrete 24 hours or even 72 hours is still not solidified, thus affecting the need for early strength of concrete and delaying the construction progress. There is no obvious influence on the concrete of proper age.
2. The impact on shrinkage: Moderate use has no obvious effect on shrinkage. When excessive use can cause coping concrete because moisture evaporates excessive generation dry crack contraction and contraction crack.
3. The impact on antifreeze durability: The antifreeze durability of concrete mixed with retarder is similar to that without retarder.
Air entraining agent:
The air entraining agent is a hydrophobic surface-active agent, dissolved in water after joining the concrete mixture, in the mixing process can produce a large number of tiny bubbles.
Air entraining agents can improve the workability, water retention, and cohesion of concrete mixture, improve the fluidity of concrete, and introduce a large number of admixtures evenly distributed, closed, and stable small bubbles in the mixing process of concrete mixture.
The main varieties of air entraining agents include rosin resin, alkyl and alkyl aromatic sulfonic acid, fatty alcohol sulfonic acid, saponin and protein salt, petroleum sulfonic acid, and so on. The commonly used dosage is cement weight 50 ~ 500ppm. Air entraining agent is mainly used for structures with high freezing resistance requirements, such as concrete dams, road surfaces, bridge decks, aircraft yard track surfaces, and other large areas vulnerable to freezing.
The accelerating agent is a kind of additive that can make concrete quickly set and harden when added to concrete. The main types are inorganic salts and organic species. Powdery solid, its admixture dosage accounts for cement dosage in concrete only 2% ~ 3%, but can make concrete in 5min initial coagulation, accelerating agent in 12min condensation. In order to achieve the purpose of rush repair or fast condensation of concrete in the tunnel. It is an indispensable additive in the shotcrete construction method. Their function is to speed up the hydration and hardening of cement, forming sufficient strength in a very short period of time to ensure the requirements of special construction.
Suppliers of Concrete Additives
TRUNNANO is a reliable concrete additives supplier with over 12-year 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.
As the duration of the conflict between Russia and Ukraine grows, its impact on commodities is widening amid the tug-of-war. Recently, European and American sanctions against Russia have been issued one after another. In response, Russia has taken advantage of its role as an important supplier of many energy and commodities, requiring exports of commodities, including energy, grain, metal, and wood, to "unfriendly" countries to be settled in robles. Therefore, it is expected that the price of the Concrete Additive will continue to increase.
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