Can white sugar delay cement solidification
Can you imagine it? When workers make cement, sugar is added. What's the secret behind this little trick? Around 1889, cement was introduced to China, starting a boom in the construction of concrete buildings.
Shortly after the founding of the State that followed, around 1952, our country developed the first unified standard and changed the generic name of cement to Portland cement.
So, what exactly is cement? It is a powdery water-hard inorganic cementitious material, after adding water to the cement and stirring it into a slurry, the cement can coagulate and tightly bond the sand and gravel.
Cement plays a vital role in building construction, and workers sometimes magically add sugar when using cement. This seemingly bizarre behavior is actually to prolong the time for the cement to solidify.
So, how does white sugar achieve this effect? This needs to be explained from a chemical point of view.
Let's take a look at what the main constituent elements of cement are. The main components of cement are calcium oxide, silicon dioxide, ferric oxide, and aluminum oxide.
The addition of white sugar can slow down the curing time of cement because of the mineral components in cement, including tricalcium silicate, dicalcium silicate, tricalcium aluminate, and tetracalcium iron aluminate.
After contact with water, the tricalcium silicate in the cement is converted to hydrated calcium silicate, which solidifies rapidly. However, if we add a small amount of white sugar to the process, we can prevent the formation of hydrated calcium silicate, thus delaying the curing of the cement.
And in this process, the amount of white sugar is very small, we only need to add 004% white sugar can double the curing time of cement, which only takes 18 hours to cure.
The miraculous effect of adding white sugar to prolong the coagulation time is applied in real life. The London Underground accident is a vivid example of this. In 2014, the cement that filled the elevator accidentally flowed into the control room, and if not treated immediately, the cement could solidify and threaten important wiring and switches, leading to serious accidents.
However, when the repair workers discovered the accident, they did not rush to remove the cement, but rushed to the store to buy sugar. They sprinkled white sugar on the cement, and amazingly, the cement in the control room did not fully solidify, but was like a puddle of mud, with no signs of solidification.
Eventually, after a clean-up, the crisis was resolved. This example once again proves the practical value of white sugar in prolonging the setting time of cement.
The application of white sugar plays an important role in life, it can solve some thorny problems and avoid unnecessary losses. Similarly, when the driver of the concrete truck encounters a traffic jam, he will also put some sugar in the jar to delay the setting time of the cement and avoid waste.
In the above incident, we can see that the right amount of white sugar can delay the setting time of cement. For example, in an accident in the control room, a large amount of white sugar was added so that the cement did not solidify.
Surprisingly, however, more than 1% of white sugar can turn cement into waste sludge. Historically, the French people during World War II took advantage of this by adding sugar to German cement, successfully thwarting their military construction.
White sugar is not uncommon on construction sites, especially as a retarder. Cement setting too quickly not only leads to waste, but can also drive up costs. As a result, white sugar is widely used on construction sites.
In addition to white sugar, special retarders are also feasible, but due to their high cost, some construction sites will choose lower cost white sugar as retarders.
Cement is not simply a sand and gravel coagulant, additives give it a variety of functions. In addition to white sugar, which can extend the setting time, there are other types of additives in cement.
First of all, white sugar plays an important role in slowing down the setting time, and at the same time, spraying sugar water on the surface of the cement and letting it dry before cleaning can create a rough and matte surface effect, which is another wonderful use of white sugar.
In addition to sugar, laundry detergent can also be added to cement to increase the slip and facilitate application. However, the wall may be white or even fall off after drying, which will do more harm than good, so it is generally not recommended to add it.
1.Mixing straw into cement can improve its toughness and thermal insulation effect, but it can lead to moth-eating and oxidation of the wall. 2.Mixing salt can enhance the thermal insulation of cement and prevent frost damage, but it should be noted that salt will accelerate the corrosion of steel bars in cement, so caution is required when using it.
3.The addition of straw to cement can enhance its properties, but be careful of the risk of insect damage and oxidation. Although salt can enhance heat preservation, its corrosive effect on steel bars needs to be paid attention to, so the state prohibits the addition of salt to cement.
By adding a variety of additives, it is possible to change the properties of the cement and achieve special effects. However, the additives added by private individuals may destroy the original properties of cement or make its properties unstable, so it is recommended to use special additives for cement with national standards to reduce the occurrence of accidents.
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