How to deal with the white ash after the concrete is exposed to the rain 5

Concrete white ash after being rained, the white ash here should refer to the "return to alkali", the solution to the alkali return is: when there is a serious return to alkali, clean with low concentration of hydrochloric acid, oxalic acid such as 5 dilute hydrochloric acid, if necessary, with a waterproof agent (or alkali cleaning agent).

The measures to mitigate alkali return are as follows:

There is no best way to reduce the probability of its occurrence as much as possible and control the amount of water added in the mixing process of dry mortar. During construction, the floor material should not leak water, and the surface should not be in contact with water before it is completely dry; During the caulk construction process, be sure to make the surface moisture evaporate as soon as possible after the sponge is wiped, or use a sponge that is not too wet.

Try to use low-alkali cement and admixtures.

Optimize the mix ratio, increase the compactness of cement-based materials, and reduce capillary pores. For example, other clinkers and fillers are used to replace part of the cement.

Re-alkali inhibitors are used. Such as elotex

ERA-100, but after use, this situation can not be completely changed, and it can only reduce the situation of alkali return to a certain extent, about 100 yuan kg, and the dosage is about per ton, if the dosage is too high, the cost is too high.

Avoid construction under dry, windy, and low-temperature environmental conditions.

Portland cement and high-strength sulfur aluminate cement are used together to have a certain effect. Here's how it works:

The Ca(0H)2 formed by the hydration of 2cao SiO2 of sulfoaluminate cement will react with other hydration products to form new compounds. 3ca(oh)

2+al2o3•3h2o+3(caso4•2 h2o)+20 h2o→3

cao•al2o3•3caso4•32h2o。Therefore, there is no Ca(OH)2 crystallization in the hydration products of sulfoaluminate cement.

Sulfoaluminate cement is used in combination with ordinary Portland cement, and the sulfoaluminate cement will consume the excess Ca(OH)2 produced by ordinary Portland cement during the hydration process, which fundamentally solves the problem of alkali return.

The fly ash in the concrete is washed out by the water, do you use commercial concrete, if so, then the front is certain, it doesn't matter, sprinkle water, just sweep with something, as long as the strength is good

White ash can be dust from rainwater, or it can be the erosion of concrete by rainwater, because rainwater is alkaline.

Commonly known as sand or ash, you don't need to deal with it, after all, you still have the building surface layer to do. When the time comes, it will be good to make cement mortar or floor tile surface layer.

There is a problem. Further observation of the strength of the concrete, such as 600 degrees, is required. If the physical strength of the day is less than 30, reinforcement measures should be considered.

Concrete 4 hours is basically the end of the initial setting, the final setting is not over the interval state, rain will change two main aspects: 1, moisture content, water-cement ratio 2, rain is unclean or contains acidic substances, will cause concrete retardation, strength decrease, and even directly generate calcium carbonate, reduce durability.

Please say something specific about the pouring site Ash number.

I've seen this happen, but it's not a lot of rain, it's just a light rain. Bridge deck cushion .

Dear, according to your description, you are answering the question of whether --- white ash can still be made of ash after rain, mainly depends on the following factors: 1pH of rainwater:

The pH value of rainwater is in the neutral and alkaline range, and there will be no significant chemical effect on white ash, and calcium oxide, the main component of white ash, will not be hydrolyzed. However, if the pH of the rainwater is low and the acidity is strong, it will have a certain dissolution and hydrolysis effect on the white ash, which will affect the activity of the white ash, and it is not suitable to be used as gray soil. 2.

The hardness of rainwater: the hardness components such as calcium and magnesium ions in the rainwater are high, which will react with the calcium oxide in the white ash to generate calcium and magnesium carbonate, etc., which will reduce the activity of the white ash, which is not conducive to chemical reaction with clay, and should not be used as ash. If the rainwater is less hard, it has less impact.

3.The amount of rainwater: the amount of rainwater is small, but the surface is wet, which has little impact on the overall activity of white ash, and can be made as gray soil.

However, if the amount of rain is large, the white ash reaches saturation and is wet for a long time, the calcium oxide in the white ash will continue to hydrolyze, and the activity will be significantly reduced. 4.Storage conditions for white ash:

If the white ash is transferred to a dry place for storage in time after rain, the activity loss will be relatively small, and it can be used as ash. However, if the cave continues to be exposed to the humid environment for a long time after the rain, the activity will be further reduced, and it is not suitable to be dusted in this case. In summary, whether the white ash can be used as ash soil after rain mainly depends on the nature of the rain and the storage conditions of the white ash.

If the rainwater has no obvious chemical effect on the white ash, the amount of rainwater is moderate, and the white ash is transferred to a dry place in time, the white ash activity will not lose too much, and it can be used as ash. Otherwise, the activity and quality of white ash will be significantly reduced, and it is not suitable to be made of ash. It is best to test the activity of white ash before making ash to ensure the quality of the ash soil.