JP2775331B2 - Mud wet subgrade improver - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a subgrade improving agent for improving a muddy subgrade, which is easily muddy by rain, to a solid subgrade.

[Conventional technology]

For example, washing water containing residual ready-mixed concrete and the like discharged when washing a concrete mixer truck is separated and recovered from the gravel and sand, and the remaining sludge water is put into a sedimentation tank, and supernatant water is recovered. The sludge water is pressure-fed to a filter press by a high-pressure pump and dewatered. If the solid filter cake discharged from the filter press is discarded as it is, it causes pollution, so that special treatment as industrial waste is required and the cost is increased.

Also, for example, when reclaiming soft soil such as swamps, for example, it has been conventionally solidified by mixing a soil conditioner such as lime,
Conventionally, there is a problem that the cost is increased since a large amount of the improver is required.

[Object of the invention]

Therefore, an object of the present invention is to reduce the cost of disposal by opening the way to effectively use the industrial waste obtained from the sludge water, and at the same time to reduce the cost of improving the muddy road subgrade.

[Means for achieving the purpose]

The muddy roadbed improving agent of the present invention achieves the above object,
Sludge water obtained by separating and removing gravel and sand from the washing residue of the ready-mixed concrete is dewatered by a filter press, and the fine-powder waste obtained by drying the filter cake is dissolved in water-soluble inorganic aluminum salt. The powder and the alkali metal carbonate powder and / or bicarbonate powder are uniformly mixed and stirred.

[Action]

Filtrate obtained by dewatering the sludge water by a filter press is dried and finely pulverized. The fine powdery waste is mainly composed of silica and calcium carbonate. If the water-soluble inorganic aluminum salt powder of the above and the powder of the alkali metal carbonate or bicarbonate such as sodium carbonate and potassium carbonate are mixed and stirred, this acts very effectively as a quick strengthening additive for cement, Improves muddy conditions.

〔Example〕

 Next, an embodiment of the present invention will be described with reference to the drawings.

The washing water discharged together with the remaining ready-mixed concrete when washing the mixer truck is subjected to gravel separation and sand separation by a trommel classifier or the like, and the remaining sludge water is stirred in a stirring tank and then pumped. Suck up at
The water is filtered by high pressure feeding to a filter press.
Then, the remaining cake is dried in a solid state by a dryer such as solar drying or hot air. This is made into a small lump by passing through a crusher and further finely pulverized by a mill such as a ball mill or a roller mill to obtain a fine powder. By milling the filter cake into a fine powder of uniform size using a mill in this way, the cured film of hydraulic cement particles in the filter cake is crushed, and the uncured component of cement comes out from the inside to the surface. come. The fine powdery waste, the water-soluble inorganic aluminum salt powder, the alkali metal carbonate powder and / or the bicarbonate powder are uniformly mixed and stirred by a mixer.

Examples of the water-soluble inorganic aluminum salt powder include aluminum nitrate, aluminum chloride, basic aluminum chloride, polyaluminum chloride, aluminum sulfate, basic aluminum sulfate, and double salts of aluminum sulfate. Aluminum powder is preferred. The alkali metal carbonate powder or bicarbonate powder is a water-soluble salt such as potassium or sodium carbonate or bicarbonate, and potassium carbonate and sodium carbonate are preferable from the viewpoint of effect.

The mixing ratio of these two powder components is almost equal in chemical equivalent ratio in terms of the effect as a quick strengthening agent, but can be arbitrarily selected. The mixing ratio of this early strengthening agent and the fine powdery waste is 2: 8, 3: 7, 4: 6, etc. according to the muddyness and wetness of the roadbed to be used. The higher the wetness, the higher the proportion of the early strengthener.

The mud wet roadbed improver of the present invention can be obtained by mixing and stirring the above components with a mixer.The fine powder has a diameter in order to prevent the fine powder from being scattered by the wind and to be easily spread on the roadbed. It is desirable to granulate to about 1-2 mm.
The powdery and granular material thus obtained is sprayed on a muddy road bed and the mud is stirred with a power shovel or the like, and the muddy roadbed absorbs moisture in a short time and solidifies.

〔The invention's effect〕

As described above, the present invention can utilize fine powdered waste obtained by dewatering, drying, and pulverizing sludge water discharged from a ready-mixed concrete plant, and not only does not require a disposal cost, but also provides a muddy road floor. It is extremely effective and very useful as an improver.

[Brief description of the drawings]

The drawing is a flow chart showing the production process of the mud wet roadbed improving agent of the present invention.

Claims (1)

(57) [Claims] 1. A fine powdery waste obtained by dewatering sludge water obtained by separating and removing gravel and sand from a washing residue of ready-mixed concrete by a filter press, and drying the filter cake; A muddy roadbed improver obtained by uniformly mixing and stirring a water-soluble inorganic aluminum salt powder and an alkali metal carbonate powder and / or bicarbonate powder.