In the entire construction process, concrete, as a basic building decoration material, is in great demand. At the same time, the quality of concrete directly determines the quality of project construction. Therefore, the quality of concrete production, transportation, and concrete pouring must be strictly controlled.
In fact, during the production and transportation process of concrete, certain problems will indeed be encountered, which may affect the quality of concrete, such as concrete segregation . Concrete segregation is one of the most common problems in concrete. It not only changes the pumping performance of concrete, but may also cause the concrete to have poorer functionality. Today we will talk about the causes of concrete segregation and how to prevent concrete segregation.
1. The reason for concrete segregation
What is concrete segregation?
Concrete segregation mainly refers to the situation where the cohesion between the raw materials of the concrete mixture is insufficient and the rough stones move downward. Under normal circumstances, if a large amount of water is metabolized in the concrete, it can be basically determined that the concrete has segregated.
After concrete is separated, the various constituent materials show an obvious layering state, with stone at the bottom and water at the top. If you mix concrete at this time, you will find that it has lost its original stickiness. Therefore, the specific manifestations of concrete after concrete segregation are: separation and layering, bottom-grabbing, poor adhesion, etc. These can cause changes in the properties of concrete, ultimately affecting the construction quality.
1. Concrete segregation caused by poor concrete quality
Concrete is the most critical ingredient of concrete. The quality of concrete directly determines the properties of concrete. In addition, concrete segregation is also closely related to concrete. Therefore, changes in concrete properties will directly affect the quality of concrete.
Cement fineness is one of the most critical parameters to consider the characteristics of concrete. It expresses the size of concrete. The finer the concrete, the larger the area after fusion with water, and the stronger the specificity. If the cement fineness decreases, the concrete material will have serious concrete segregation problems. Therefore, the higher the properties of concrete, the more likely it is that concrete will segregate.
In addition, the level of alkali content in concrete also determines the characteristics of concrete. If the alkali content is high and low, it is easy to cause concrete segregation problems. In addition, the concrete that has just been driven into the concrete silo may also cause concrete segregation due to excessive temperature. In other words, after concrete segregates, the first thing that comes to mind is to check whether the quality of the concrete has changed.
2. Stones cause concrete segregation
The combination of coarse stone and fine stone can Making the voids inside the concrete smaller can better ensure the fluidity of the concrete and avoid the problem of concrete segregation. Secondly, �If the mud content in the stone is too high, the performance of the concrete will be worse, and eventually it will cause concrete segregation.
In addition, if the water content in the sand and gravel is high, it will cause the water in the sand and gravel to be unable to be squeezed out effectively during the mixing process of concrete. After molding, large bubbles will be generated in the sand and gravel, which is detrimental to the reliability of the concrete. Moreover, if unnecessary water is metabolized during transportation, this will directly cause concrete segregation.
3. Concrete segregation due to admixtures
There are many types of admixtures, and , they also have different functions. For example, admixtures are used to reduce the amount of raw concrete water used, which can not only ensure the circulation performance of concrete, but also effectively prevent concrete segregation. Since the water content in concrete is reduced, the probability of concrete segregation will also be greatly reduced.
However, if the wrong type of admixture is used, or the wrong amount is used, it will also cause concrete segregation problems. Therefore, admixtures have two sides, with both benefits and disadvantages. How to use admixtures must be determined according to the specific situation. Do not increase or decrease the demand for admixtures arbitrarily.
4. Concrete segregation caused by machinery and equipment
During the processing of concrete, various The usage amounts of various raw materials are strictly formulated and accurately measured and verified by the weighing system of the concrete mixing station. However, the probability of weighing system software failure is still quite high. If, during the processing of concrete, more or less of a certain type of raw material is used, the properties of the concrete will be immediately changed. Referring to the three causes of concrete segregation above, mechanical failure is likely to cause concrete segregation.
2. What are the damages caused by concrete segregation?
1. The pumping performance of concrete is reduced
Concrete pumping characteristics, the most visual The main performance is the fluidity of concrete. After concrete segregates, the fluidity will decrease linearly. This will cause the problem of pump clogging to occur easily during the underwater concrete process. Most concrete segregation problems are caused by concrete segregation.
2. Reduced concrete quality
After the concrete is segregated, the concrete layer will remain unchanged during the entire concrete pouring process. During the process, the sand and gravel at the bottom increased, while the surface layer was mostly cement mortar. After hardening, the concrete will easily become dusty and dusty, which will directly lead to poor construction quality. In addition, after concrete is separated, the stone voids in the concrete will be too large, which will cause air bubbles in the concrete and lead to a honeycomb state. Or, the strength of the concrete after hardening is insufficient, which can easily lead to cracking problems.
3. Prevent concrete segregation
First of all, perhaps we should strictly control production The quality of concrete raw materials, especially after changing cement manufacturers, or new concrete, samples must be kept to test the characteristics of the concrete. For stone materials, the water content and mud content must be strictly monitored.
During the processing process, the mixing ratio must be strictly implemented to produce concrete. The operator cannot change the amount of certain types of raw materials in the concrete at will. During the transportation process, no one can add water or other preservatives to the concrete casually to ensure the integrity of the concrete quality.
Concrete segregation is a problem that cannot be controlled. The specific situation must be viewed in detail. During normal processing, the production process flow should be strictly followed. Analyze the probability of problems from various fields and defeat them one by one.
, 51); font-family: Arial, Helvetica, sans-serif; font-size: 13px; white-space: normal; background-color: rgb(255, 255, 255);"/> First, Perhaps it is still necessary to strictly control the quality of concrete raw materials. Especially after changing cement manufacturers, or new concrete is purchased, samples must be taken to test the characteristics of the concrete. As for stone materials, the water content and mud content must be strictly monitored. During the processing process, the mixing ratio must be strictly implemented to produce concrete, and the operator cannot change the amount of certain types of raw materials in the concrete at will. During the transportation process, During the process, no one can add water or other preservatives to the concrete casually to ensure the integrity of the concrete quality.
Concrete Segregation It is a problem that cannot be controlled, and the specific situation must be viewed in detail. During daily processing, the production process should be strictly followed. Analyze the probability of the problem from various fields and overcome it one by one.
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