Contents of this article
Concrete segregation problems and treatment methods?
What should I do if the separated concrete has hit the roof?
What should I do if the concrete segregates? What causes it and how to solve it?
What are the causes and solutions for segregation during concrete pouring?
What if the concrete falls apart on the ground?
The concrete is seriously segregated and has been poured into the shear wall. How to deal with it, grouting? Please be more detailed. Thank you. Urgent?
How to solve concrete bleeding and segregation? What admixtures can be adjusted?
How to deal with the segregated material?
Concrete segregation problems and treatment methods?
The main cause of concrete segregation problem is that it is stopped for too long without stirring, or the water-cement ratio is too high. Treatment method Generally speaking, the first phenomenon requires timely stirring and slump test. Normal construction can only begin after the slump test is suitable. If the water-cement ratio is too large, it is necessary to adjust the water consumption in time. It is best to have a tool or meter to measure the water volume.
What should I do if the separated concrete has hit the roof?
Before concrete is mixed and produced, mix proportion tests of various raw materials must be carried out according to different design labels. In terms of mixing quality, it is required to meet the mixing time so that the workability, slump, and other indicators of the concrete meet the requirements. At the same time, segregation must be prevented during transportation and pouring. Now that problems arise, the quality of the project cannot be guaranteed. The pouring construction should be stopped immediately, the concrete that has been poured should be removed and removed, and the concrete that has been poured should be reworked and poured with qualified concrete. At the same time, claims were made against the relevant responsible units, and the on-site construction leaders and technical leaders of the units were criticized and punished.
What should I do if the concrete segregates? What causes it and how to solve it?
Causes for segregation during concrete pouring: Improper pouring and vibration, the maximum particle size of the aggregate is too large, the proportion of coarse aggregate is too high, the content of cementitious materials and fine aggregate is low, The density of coarse aggregate is too high compared with fine aggregate, or the mixture is too dry or too thin, etc. The tendency to segregation can be reduced by using mineral admixtures or air-entraining agents. Methods to deal with segregation during concrete pouring:
1. The problem of concrete segregation caused by the problem of aggregate moisture content should be solved by extending the mixing time. Increasing the dosage of admixtures such as fly ash is also very effective in controlling this type of segregation phenomenon.
2. During the construction process, we must strictly control the quality and resolutely prevent unqualified materials from entering the construction site to ensure the stability of the quality of the aggregate;
3. If the water content in the sand is In the saturated state (≥10%), the method of extending the mixing time is used to solve or increase the amount of admixtures such as fly ash to control the segregation problem of commercial concrete.
4. Increase the sand rate to adjust the concrete mix ratio and solve the segregation problem. Extended information: The hazards of concrete segregation: 1. It affects the pumping construction performance of concrete, causing sticky tanks, blocked pipes, affecting the construction period, etc., and reducing economic benefits. 2. It affects the appearance of the concrete structure, with sand patterns, exposed aggregates, and exposed steel bars appearing on the surface of the concrete. 3. The strength of concrete will be greatly reduced, which will seriously affect the bearing capacity of the concrete structure and destroy the safety performance of the structure. In severe cases, it will cause rework and huge economic losses. The poor homogeneity of concrete results in inconsistent shrinkage of various parts of the concrete and is prone to shrinkage cracks in the concrete. Especially when constructing concrete floor slabs, due to concrete segregation, the surface cement slurry layer thickens, shrinkage increases sharply, and serious cracks occur. It greatly reduces the durability properties of concrete such as concrete impermeability and frost resistance.
What are the causes and solutions for segregation during concrete pouring?
Where should the segregation of concrete be divided? If the segregation occurs during transportation, it may be that your transportation machinery is not good enough. Generally, this phenomenon will not occur if you use a concrete transport truck (called a snail truck in Guangdong). Segregation on the warehouse surface is not easy to deal with. Especially on the side of the formwork, the accumulation of coarse aggregate can easily produce honeycomb pockmarks. If there is too much slurry, it is easy to produce concrete that is caused by segregation of the slurry after pouring. For honeycombs and pockmarks, cut out the honeycombs and pockmarks, then plaster the surface with glue mixed with cement mortar, and it’s OK
What should I do if the concrete falls apart on the ground?
If the concrete falls apart when poured on the ground, it may be segregated. To deal with such a problem, you must first know the cause of the problem. Generally, it is because the mixing time is not enough, or the mix ratio is unreasonable, and the proportion of cementitious materials is too small. Therefore, when encountering such problems, the general principle of handling is to first add the same proportion of mortar , after sufficient mixing, check whether the workability of the concrete meets the requirements.
The concrete is seriously segregated and has been poured into the shear wall. How to deal with it, grouting? Please be more detailed. Thank you. Urgent?
It has been poured. Let’s wait until the concrete hardens and the formwork is removed.
If it is not serious, you can clear this part of the hardened concrete and pour it back with higher-grade fine stone concrete. If it's serious, a whole section of the wall can be cut out and concrete poured again.
Write the above opinions into a repair plan and submit it to the supervision engineer. The repair plan must be approved by the supervision engineer.Repaired. (If the above does not solve your problem, you may wish to send a photo for further analysis.)
How to solve the problem of concrete bleeding and segregation? What admixtures can be adjusted?
1. Increase the strength of concrete
After using concrete strengthening agent, the strength of concrete can be increased by 8% to 20%; while the strength remains unchanged, the amount of cement can be reduced 10%~20%.
2.
Improve the performance of concrete
Concrete strengthening agent can effectively improve the workability, bleeding resistance, non-segregation and easy pumping of concrete. And the frost resistance and carbonation resistance have been greatly improved.
3.
Strong adaptability
Not only can it be suitable for various types of concrete and has strong compatibility with various types of admixtures, but it can also improve the The adaptability of carboxylic acid water-reducing agents to raw materials (such as low-quality fly ash, sand with a large mud content, and stones with a large stone powder content) reduces the sensitivity to changes in the dosage of polycarboxylic acid water-reducing agents. It can effectively control the negative phenomena (segregation, poor encapsulation) when the amount of water-reducing agent is high.
4.
Green and environmentally friendly
The potent agent is non-toxic, harmless, non-polluting and non-radioactive, and does not contain chloride ions and alkali.
How to deal with the segregated material?
Causes for segregation during concrete pouring: Improper pouring and vibration, the maximum particle size of the aggregate is too large, the proportion of coarse aggregate is too high, the content of cementitious materials and fine aggregate is low, The density of coarse aggregate is too high compared with fine aggregate, or the mixture is too dry or too thin, etc. The tendency to segregation can be reduced by using mineral admixtures or air-entraining agents. Methods to deal with segregation during concrete pouring:
1. The problem of concrete segregation caused by the problem of aggregate moisture content should be solved by extending the mixing time. Increasing the dosage of admixtures such as fly ash is also very effective in controlling this type of segregation phenomenon.
2. During the construction process, we must strictly control the quality and resolutely prevent unqualified materials from entering the construction site to ensure the stability of the quality of the aggregate;
3. If the water content in the sand is In the saturated state (≥10%), the method of extending the mixing time is used to solve or increase the amount of admixtures such as fly ash to control the segregation problem of commercial concrete.
4. Increase the sand rate to adjust the concrete mix ratio and solve the segregation problem. Extended information: The hazards of concrete segregation: 1. It affects the pumping construction performance of concrete, causing sticky tanks, blocked pipes, affecting the construction period, etc., and reducing economic benefits. 2. It affects the appearance of the concrete structure, with sand patterns, exposed aggregates, and exposed steel bars appearing on the surface of the concrete. 3. The strength of concrete will be greatly reduced, which will seriously affect the bearing capacity of the concrete structure and destroy the safety performance of the structure. In severe cases, it will cause rework and huge economic losses. The poor homogeneity of concrete results in inconsistent shrinkage of various parts of the concrete and is prone to shrinkage cracks in the concrete. Especially when constructing concrete floor slabs, due to concrete segregation, the surface cement slurry layer thickens, shrinkage increases sharply, and serious cracks occur. It greatly reduces the durability properties of concrete such as concrete impermeability and frost resistance.
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