Why does concrete turn sand, the difference between concrete sand and sand

Sand on the surface of concrete usually occurs in large-area engineering construction such as ground and floor slabs!!

The factors that cause this are:

1. The raw material sand is too fine, the mud content is too high, and the fly ash is too coarse;

2. Mix ratio design The sand rate is too large, and the fly ash output is too high;

3. Production During production, the concrete collapse is too large, and the water consumption exceeds the standard;

4. Construction: During construction, the powder (especially fly ash) floats due to excessive vibration, and a slurry layer is formed on the surface of the concrete; At the same time, over-vibration is also easy to cause the occurrence of aggravated concrete surface water leakage, so that the surface water-cement ratio is too large, when the slurry layer and water leakage are not treated in time, it will cause the concrete surface strength to be reduced, thus producing the phenomenon of sand (note: watering and curing when the concrete has not yet been set will also cause a similar phenomenon).

The solution is nothing more than to strictly control the quality of raw materials, reduce the sand rate and reduce the amount of fly ash as much as possible (we now do not mix fly ash on the dump ground), control the collapse of concrete, and communicate with the construction site in a timely manner to avoid the negative impact caused by construction!!

The above is just a little personal understanding, there may be a lot of shortcomings, I hope to communicate more in the future work, common progress, thank you!!

There are several reasons, such as large sand rate, fine sand, large concrete slump, excessive vibration, and failure to cover in time after pouring rain.

Over-vibration, too large sand rate, too large slump or even segregation, fly ash is too coarse or too high is the main reason for concrete sanding, if the pavement concrete should not be mixed with fly ash.

Let's dissect. Thickening, bleed air can solve this problem.

Summary. Concrete sanding and sand turning are two different phenomena, I will simplify your question. Concrete sanding refers to the fact that when mixing concrete, some aggregates with larger particles or lower density will detach from the surface of the concrete or fall below, resulting in sand or potholes on the surface, affecting the quality of the concrete.

Sand turning refers to the appearance of a sand-like substance on the surface of concrete during construction, which may be caused by improper vibration or pouring machinery during construction. Hope this meets your requirements.

Concrete sand and sand turning are two different phenomena, and I will answer your question in a simple return to the slag. Concrete sanding refers to the fact that when mixing concrete, some aggregate stove beams with larger particles or lower density will detach from the concrete surface or fall below, resulting in sand or potholes on the surface, affecting the quality of concrete. The concealed sand turning refers to the appearance of a layer of sand-like substance on the surface of the concrete during the construction process, which may be caused by improper vibration or pouring machinery during construction.

Hope this meets your requirements.

You've done a great job! Can you elaborate on that?

Concrete sand sand and sand turning are two different phenomena. Concrete sanding refers to the fact that when mixing concrete, the aggregate detaches from the surface or falls below, resulting in sand or potholes on the surface, which affects the quality. Sand turning refers to the appearance of sand-like substances on the surface during the construction process, which may be caused by vibration or improper pouring machinery.

I hope it doesn't meet your requirements.

Generally after three years.

Ordinary cement mixed concrete floor is generally used for 3 years, under the action of forklifts, the ground will have different degrees of sand, dust, with the growth of service life, plus carbonization, water erosion and weathering, the surface of the floor will continue. When there is a phenomenon of sand and ash on the ground, the general method on the construction site is to smear a layer of plain ash on it to cover the sand floor.

Sand turning solution

First of all, remove the dust, debris, stones and other residues on the surface, clean the rotary base surface, then select the cement floor sanding treatment agent and ground solid material at the first point, and mix the treatment agent evenly according to the proportion on the manual, and then use a brush or roller front file to dip an appropriate amount of mixture on the ground that needs to be turned sand for brushing, which must be evenly applied to the surface.

Finally, after drying, you can water and cure. Note that watering and maintenance must be carried out according to the weather temperature. Ground sand turning treatment method. Remove dust, debris, meganuclear stones and other residues from sanding on the surface, and clean the construction base surface.

Choose the most advanced cement floor sand treatment agent and ground solid material, mix the treatment agent evenly according to the proportion on the manual, and use a brush or roller to dip the appropriate amount of mixture on the ground that needs to be turned over the sand to paint, which must be evenly smeared on the surface, and then watered and cured after drying.

1. First clean up the damaged cement pavement The concrete pavement base layer is cleaned up, and the loose stones, sand and fallen objects are removed, revealing a solid surface layer for later use. 2. Wash the road surface with a high-pressure water gun to prevent sewage from backflowing, and try to flush in one direction. 3. The clear water on the road surface washed by the road breeze, and the road surface should be kept moist without clean water.

4. Open the outer packaging bag of cement pavement concrete pavement repair materials, prepare a mixer or mixing drum, and hold a mixing drill and clean water. Put a certain proportion of clean water lead in the mixing barrel, pour in the dry powder BT water core mud pavement repair material and concrete pavement repair material, and fully stir evenly for later use. 5. Prepare the mixed BT cement pavement repair material BT concrete pavement repair material on the pavement to be repaired and compact it with a manual trowel.

6. The repaired cement pavement should be maintained in time, and it can be sprinkled and cured once within 24 hours. After the maintenance water is completely dry, Huai Shiheng can be opened to traffic.

1. First look at whether the water-cement ratio of concrete is appropriate, the water-cement ratio is too large, which is easy to segregation and water leakage, resulting in sanding of the surface layer;

2. Secondly, see whether there is excessive vibration during construction, which is very prone to serious segregation and water leakage;

3. If it is the ground, it also depends on whether the surface is plastered and calendered in time;

4. Fourth, to see whether it is maintained in time, the necessary maintenance should be carried out to prevent the water-cement ratio of the concrete surface from being too large or the water is lost before the surface strength is not established, the water dispersion of the concrete surface layer is too fast, and the surface cement can not be fully hydrated, which will also lead to low surface concrete strength and loose structure.

The water-cement ratio is too large: that is, the amount of water in the mixed concrete is large, which leads to water leakage on the concrete surface and reduces the strength of the concrete surface.

2.Unreasonable gradation of sand and gravel and high mud content: Unreasonable gradation of aggregate and too fine soil and sand can easily lead to sand on the ground, affecting the early hydration of cement and the coagulation of concrete.

3.Excessive vibration during construction: exacerbates water leakage on the concrete surface, resulting in low concrete surface strength.

1. First look at whether the water-cement ratio of concrete is appropriate, the water-cement ratio is too large, which is easy to segregation and water leakage, resulting in sanding of the surface layer;

2. Secondly, see whether there is excessive vibration during construction, which is very prone to serious segregation and water leakage;

3. If it is the ground, it also depends on whether the dust is wiped and calendered in time;

4. Fourth, to see whether the timely maintenance should be carried out, the necessary maintenance should be carried out to prevent the water-cement ratio on the surface of the mixed concrete from being too large or the water is lost before the surface strength is not established, the water dispersion of the concrete surface layer is too fast, and the surface cement can not be fully hydrated, which will also lead to low surface concrete strength and loose structure.

Concrete, right? If you use commercial concrete, the sand part of the road is sanded, and the fly ash parameter can not be more. The only way to solve this problem is to sprinkle a layer of cement on the surface after the construction is completed.

After hardening, only a layer of glossy mortar can be applied.

The reasons for the sand turning of the concrete pier are:

1. First look at whether the water-cement ratio of concrete is appropriate, the water-cement ratio is too large, which is easy to segregation and water leakage, resulting in sanding of the surface layer;

2. Secondly, see whether there is excessive vibration during construction, which is suspected to mean that serious segregation and water leakage are prone to occur;

3. If it is the ground, it also depends on whether the surface is plastered and calendered in time;

4. Fourth, to see whether it is maintained in time, the necessary maintenance should be carried out to prevent the water-cement ratio on the surface of the concrete from being too large or the moisture is lost before the surface strength is established, and the water dispersion of the concrete surface layer is too fast, and the surface cement can not be fully hydrated, which will also lead to low surface concrete strength and loose structure.