JP2840880B2 - Method for producing self-hardening backfill material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for producing a material used for backfill work.

<Conventional technology> Backfilling is, for example, excavating the ground, suspending fume pipes and the like inside the excavated trench, backfilling the surrounding area, constructing an underground structure, The work is to fill the space where it was located or the trace of the H steel that was pulled out.

<Problems to be solved by the present invention> In such conventional backfilling work, sandy soil is compacted by a tamper.

<Means for Solving the Problems> In such conventional compaction work, since the material to be used is sandy soil, there are the following problems.

<B> Since sandy soil is not self-hardening, it is easily eroded when the backfill site is affected by groundwater.

As a result, voids are created in the ground, causing the surface to sink.

<B> The width is extremely narrow around the traces of H steel and around the walls of underground structures.

Therefore, sufficient sandy soil cannot be filled, and at the same time, compaction work cannot be sufficiently performed.

<C> The earth and sand for backfilling must be transported from a distance, which is uneconomical.

<Object of the present invention> The present invention has been made in order to improve the conventional problems as described above, and has as its object to provide the following method for producing a backfill material.

<A> A method of manufacturing a backfill material having self-hardening properties, and does not flow out even by groundwater to generate voids. <B> A method of manufacturing a backfill material that can sufficiently flow into a narrow space. C> Method of manufacturing backfill material for easy transportation <Means for solving the problems> That is, the present invention relates to mixing fly ash and clinker ash with cement, a thickener, water, and a foaming agent. First, a self-hardening backfill material is produced by mixing water and a foaming agent, and then mixing a thickener with cement, fly ash, and clinker ash.

<Description of the Present Invention> Hereinafter, the present invention will be described in detail.

<A> Basic Configuration of the Present Invention The backfill material of the present invention is basically composed of the following materials.

Raw material of fly ash Clinker ash Portland cement Thickener mainly composed of cellulose ether Foaming agent mainly composed of higher alcohol sulfate compound Water <b> Function of self-hardening backfill material Since it has such a function, it can be effectively used as a backfill material.

High fluidity The material of the present invention has high fluidity before curing. For example, the JIS table flow value is 30 cm or more.

Therefore, pressure feeding by a pump is possible, and filling in a narrow place can be performed.

Further, since the fluidity is high, it is possible to sufficiently fill every corner of the narrow gap without performing the compacting operation.

No breathing occurs The material does not breathe during the setting process. Therefore, after filling and curing, there is no adverse effect such as generation of a void in the periphery.

Self-hardening properties The material has self-hardening properties and hardens in a relatively short time.

Therefore, there is no danger of dissolving or flowing out due to groundwater flow, and it is stable for a long time.

Moderate strength The strength after hardening is almost the same as that of normal ground, and there is no obstacle to re-digging the backfill site.

The compressive strength after hardening is 3 to 4 (kgf / cm ² ) in 7 days of age, and can be easily excavated with a normal excavator.

<Formulation Example> An example of the composition of the material of the present invention will be described.

W Water C Ordinary Portland cement F Fly ash raw powder Ash Clinker ash (dry mass) Add.1 Thickener Add.2 Foaming agent <Description of materials> Next, the properties and functions of the basic materials will be described.

Fly ash raw material In the fly ash calculated from the coal-fired power plant,
Use unclassified ones.

The use of such a raw powder is inexpensive because it has not been subjected to a classification operation.

The fly ash used for the test had a specific gravity of 2.13.

Clinker ash This is the bottom ash of a coal-fired power plant and is usually used for landfill as industrial waste.

The clinker ash is discharged in a wet state because it has been cooled with water.

The clinker ash used for the test kneading has a dry specific gravity
1.67, and the particle size curve is as shown in FIG.

Thickeners Thickeners are used to resist material separation and to suppress the occurrence of breathing.

The state where the breathing rate changes depending on the amount of the thickener used and the mixing order was compared.

FIG. 2 shows a comparison of the breathing rates of the above three types of samples.

From these results, the effect of the addition of the thickener could be known, but in particular, the effect of mixing the thickener with the cement could be known.

That is, when the thickener was mixed with the cement at the same time, an effect that no breathing occurred was achieved.

Foaming agent The use of the foaming agent in the present invention is to achieve the following functions.

(1) Adjustment of strength (2) Material saving by volume increase (3) Suppression of breathing (4) Reduction of importance of unit volume To know how much the breathing rate is reduced by using the effect of the foaming agent, The following comparative test was conducted.

As is clear from the above comparison, the addition of the foaming agent (Sample 2) did not cause an increase in consistency,
The unit volume weight and the compressive strength were reduced, and the breathing could be suppressed.

Selection of Foaming Agent Although various foaming agents are known, a general foaming agent tends to have a reduced foaming property when used in combination with fly ash. Therefore, in the case of the present invention, it is necessary to wash a foaming agent capable of introducing stable air bubbles even when used in combination with fly ash.

Therefore, a comparative test was performed on the following four types of foaming agents, and the optimum one was selected.

(1) Fine Form 606 (Nisso Master Builders Co., Ltd .: higher alcohol sulfate compound) (2) Escort L (Manol Co., Ltd .: special synthetic surfactant) (3) Monocrete (Daiichi) (Kasei Sangyo Co., Ltd .: Animal hydrolyzed protein) (4) Fine Form 505 (Nisso Master Builders Co., Ltd .: Polyoxyethylene alkyl allyl ether compound) Addition method of foaming agent W and foaming agent are mixed first, and then C + F + Ash
+ Mix thickener.

From the above comparison, it was determined that (1) and (2) as the foaming agents had excellent bubble-introducing power.

Comparing the two, it was found that in (1) fine bubbles were dispersed on the surface after curing, whereas in (2) the bubbles were rough.

Therefore, it was determined that the use of the fine form 606 was suitable for the material used in the present invention.

<Effects of the Present Invention> Since the method for manufacturing a backfill material of the present invention has the above-described configuration, the following effects can be achieved.

<B> The backfill material enhanced by the method of the present invention has good fluidity.

Therefore, a narrow space can be completely filled without compaction, and there is no occurrence of poor construction due to insufficient compaction as in conventional sandy soil.

<B> The backfill material produced by the method of the present invention has a self-hardening property. Therefore, even if the ground has groundwater, it is not eroded, and a stable function can be maintained for a long time.

<C> Clinker ash from a coal-fired power plant, which was conventionally dumped as industrial waste, can be used, so that resources can be effectively used.

<D> Since no breathing occurs after mixing, no space is generated after filling, and complete filling is possible.

<E> Since the hardness after hardening is about 3 to 4 (kgf / cm ² ), it can be performed by the same operation as ordinary earth and sand excavation when excavating again.

[Brief description of the drawings]

Fig. 1: Particle size curve diagram of clinker ash Fig. 2: Diagram showing the relationship between the timing of adding a thickener and the breathing rate

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C04B 103: 44 103: 48 111: 70 (72) Inventor Akio Toba 1-23-9 Nakahara, Kashiwa-shi, Chiba (72) Inventor Yoshiaki Hayashida 318 Tenjin-cho, Kamimaruko, Nakahara-ku, Kawasaki-shi, Kanagawa (56) References JP-A-4-182334 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C04B 28/00-28 / 36 C04B 18/08-18/10 C04B 24/16

Claims (2)

(57) [Claims] (1) When mixing cement, a thickener, water and a foaming agent with fly ash and clinker ash, first, water and a foaming agent are mixed, and then, a thickener and cement, fly ash, Method for producing self-hardening backfill material by mixing with clinker ash 2. The method for producing a self-hardening backfill material according to claim 1, wherein a higher alcohol sulfate compound is used as a foaming agent.