WO2003048457A1

WO2003048457A1 - Method of constructing civil work bedding layer and bedding material for civil work

Info

Publication number: WO2003048457A1
Application number: PCT/JP2002/012566
Authority: WO
Inventors: Takeshi Nakagawa
Original assignee: A Joint-Stock Corporation Kawashima Industry
Priority date: 2001-12-07
Filing date: 2002-11-29
Publication date: 2003-06-12
Also published as: AU2002349659A1; JP3769521B2; CN1599826A; JP2003232003A

Abstract

A method of constructing a civil work bedding layer and a bedding material for civil work capable of solving a reclamation disposal problem by effectively utilizing ash produced at various places and also providing a stable bedding layer with excellent strength, the method characterized by comprising the step of forming a civil work bedding layer by laying down, at a bedding formed part, bedding materials for civil work at least added with ash containing a calcium oxide of 15 wt.% or more such as roadbed material, back-filling material, and backing material.

Description

Specification

Construction method of civil engineering foundation layer

Technical field

The present invention relates to a construction method of a civil engineering foundation layer and a foundation material for civil engineering work.

Background art

Garbage discharged from households is generally incinerated at garbage incineration sites of local governments. And the incineration ash generated by this incineration is landfilled at a landfill.

However, there is a limit to the space at the landfill site, and there is a need for a method for effectively using incinerated ash without landfill.

In addition, recently, concrete crushed concrete as a result of excavation during road repairs, as well as crushed concrete crushed asphalt hulls, asphalt crushed frames, and recycled products such as reclaimed crusher runs, etc. Is used as a base layer forming material for civil engineering foundation material that forms the lower road body of concrete, but the concrete frame and asphalt crushed material used as the civil engineering foundation material However, although the particle size of recycled products such as reclaimed crusher runs is regulated, the particle size distribution is wide, so the vibration during transportation by a dump truck or the like may cause Coarse-grained materials are separated, and road bodies and lower subgrades made using this recycled product also have coarse aggregates in the upper layer and lower layers. It made many fine aggregate. Therefore, if the compaction during construction is not sufficient, the gap between the coarse aggregates will be large on roads where large vehicles and other vehicles pass frequently, and the roadbed will not be stable. There is a problem in that the road surface is settled, making it easier to make ruts and increasing the frequency of repairs.

In view of the above circumstances, the present invention can effectively solve the problem of landfill disposal by using ash generated in various places, and can obtain a stable underlayer excellent in strength and stable. The purpose of this method is to provide a base material for civil engineering work. Disclosure of the invention

In the construction method of the civil engineering foundation layer of the present invention, the timing of adding the ash to the other civil engineering foundation material may be such that the ash is added to the aggregate or the like in advance at a factory or the like or may be added immediately before the construction. I do not care.

In the present invention, the foundation material for civil engineering work means a material disposed below a surface material of a civil engineering structure, and includes, for example, a roadbed material, a retaining wall, and the like that form a roadbed that is a foundation of a pavement road. There are backfill materials provided on the back, and backfill materials (also referred to as “roll-up materials J” or “cushion materials”) that are provided around the pipes when backfilling the pipes during construction of excavated pipes.

In addition, when this civil engineering construction base material is used as a roadbed material, for example, the lower roadbed of asphalt pavement, the roadbed of concrete pavement, the roadbed of parking lot, the roadbed of ground, and the upper roadbed of asphalt pavement can be formed. Although it can be used, it is particularly suitably used for forming the upper subgrade. In addition, cement can be used to form a water-resistant, drainage pavement base. In the present invention, it is essential that the ash contains 15% by weight or more of calcium oxide, and it is preferable that the ash contains 20% by weight or more. The effect of calcium oxide increases the strength of the underlayer formed by this underlayer over time, but if the content of calcium oxide is less than 15% by weight, the effect becomes insufficient. is there.

The ash is not particularly limited as long as it contains 15% by weight or more of calcium oxide, as described above. The method described in Japanese Patent Application Laid-Open No. 2001-132930 It is preferable to use ash that has been detoxified by decomposing or removing dioxins and heavy metals, etc. (hereinafter referred to as “roasting furnace ash”).

The particle size of the ash is appropriately determined depending on the use of the foundation material for civil engineering work.For example, when the ash is used as an upper roadbed or a lower roadbed such as asphalt pavement, a minimum particle size product, a medium / small particle size product, and a medium particle size It is preferable to mix the large particle size product and the maximum particle size product at substantially the same ratio. In addition, as a roadbed of permeable pavement When using. It is preferable to mix the medium-grained product and the large-grained product in the same amount, and to mix cement.

Furthermore, when this civil engineering construction base material is used as a backfill material,

A mixture of a lump of 0.6 mm or more (preferably 0.6 mm or more and 2 mm or less) and sand is suitably used. That is, if the ash has a particle size of less than 0.6 mm, the cushioning property required as a backfill material may not be able to be secured.

When used as a backfill material, the mixing ratio of ash and sand is not particularly limited, but is preferably about 3: 1 to 1: 3.

In the foundation material for civil engineering work of the present invention, other additives such as lightweight aggregate and cement may be added depending on the use. For example, if cement is added, a water-resistant roadbed used for permeable pavement can be formed.

In the present invention, coarse aggregates have a particle size of 3 mm or more and 40 mm or less, preferably 5 mm or more and 15 mm or less, and fine aggregates have a particle size of less than 3 mm, preferably 0. It means the thing of 1 mm or more and 2 mm or less.

Coarse aggregates and fine aggregates are not particularly limited.Examples of coarse aggregates include gravel, crushed concrete, crushed asphalt, recycled products such as recycled crushers, and melted slag. Examples of fine aggregate include sand, molten slag, etc.Crushed stones composed of a mixture of large aggregates of coarse aggregate and fine aggregates of fine aggregate may be used. When used, it is preferable to use gravel as coarse aggregate and sand and Z or slag as fine aggregate.

When used as a roadbed material, the mixing ratio of ash, coarse aggregate and fine aggregate is 1.0-2.5: 0.5-1.5: 0.3-1.3. It is preferably blended at a ratio of 0, 1.5 to 2.5: 0.75 to: L. 25: 0.3 to 0.7, more preferably, 2.0 to 1.0: 0.5 is even more preferred.

The construction method of the civil engineering foundation layer of the present invention uses ash that has been conventionally landfilled. Landfill disposal is not required. Further, the ash adheres to the surface of another underlayer forming material, and this ash solidifies with time, so that a strong underlayer can be formed. It seems that ash, coarse aggregate and fine aggregate are blended in a volume ratio of 1.0 to 2.5: 0.75 to 1.5: 0.3 to 1.0. In this case, the ash will be moistened by water and will not be scattered by wind or the like.

Since the ground material for civil engineering work of the present invention uses ash that has been conventionally disposed of in landfill, landfill disposal is not required. Also, the ash solidifies over time, and a strong underlayer can be formed.

Further, when compacted, it is preferable to include ash, coarse aggregate, and fine aggregate so that the particles can be finely packed with each other.

When compacted, the calcium oxide contained in the ash becomes bonded with time, and when used as a roadbed material, the roadbed strength is improved over time and a stronger roadbed is formed.

When embedding a pipe, it is preferable to use a mixture of massive ash and sand having a particle size of 0.6 mm or more so that the ash is crushed during compaction and the pipe is protected well.

Further, it is preferable that the foundation material for civil engineering work of the present invention contains water in advance so as to be hardly scattered by wind or the like.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an explanatory view illustrating one embodiment of a method of manufacturing a roadbed material which is an example of the foundation material for civil engineering according to the present invention, and FIG. 2 is a diagram illustrating the foundation for civil engineering according to the present invention. FIG. 6 is a cross-sectional view illustrating a method of applying a backfill material as another example of the material.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited to these embodiments.

As shown in FIG. 1, a roadbed material 1 as a foundation material for civil engineering work according to the present invention includes a ash 2 containing calcium oxide (lime) such as a roasting furnace ash, and a coarse aggregate 3 And the fine aggregates 4 such as molten slag and sand have a volume ratio of 1.5-2.5: 0.75-1.5.25: 0.3-0.7. It can be obtained by supplying the mixture to the mixer 5, mixing uniformly in the mixer 5, and adding 5 to 7% by weight of water 6.

The roadbed material 1 can be formed by laying the roadbed material in a roadbed forming portion and compacting the compacted material using a compacting device such as a roller, a vibration compactor, a rammer, or the like.

Since the roadbed material 1 is configured as described above, it has the following excellent effects.

(1) Since ash 2 to be discarded is used, landfill disposal of ash 2 is not required, and ash disposal costs can be reduced.

(2) Since the material does not solidify even if left for a long time, there is no restriction on the construction time.

(3) The roadbed strength is obtained by compaction and then solidified, so it has excellent pierceability.

(4) Not only grader construction in conventional granular subgrade construction, but also construction with a finisher, etc. is possible, and it has excellent non-landing performance, so it is rich in flatness in machine construction and suitable for human-powered construction .

(5) Since it is water-absorbing, it can be used as a roadbed surface drainage layer by simply mixing cement and compacting it, and can also prevent heat islands and the like.

(6) Since water is added in advance, there is no scattering of particles such as ash 2 during construction, and the workability is excellent.

The roadbed obtained by using the roadbed material 1 includes the ash 2, the coarse aggregate 3, and the fine aggregate 4, so that when compacted, the particles are finely packed with each other. Therefore, a solid roadbed can be obtained. In addition, the compaction causes the calcium oxides contained in the ash to be in a state of being bonded to each other, which makes the ash stronger. In addition, since it is solidified only by compaction and not mortar, it is possible to easily excavate the roadbed when repairing road surfaces. In addition, it can be reused as roadbed material.

As shown in FIG. 2, the backfill material 7 as a foundation for civil engineering work according to the present invention has a volume ratio of lump of ash having a particle size of 0.6 mm or more and sand having an average particle size of 1: 1. After filling the area around the pipe 9 laid in the excavation groove 8 formed by excavating the ground G, compacting it, and gravel (not shown) on the top of the backfill material 7, After putting the soil and compacting it, asphalt pavement is applied.

In other words, if the above-mentioned backfill material 7 is used, since the backfill material 7 contains massive ash with a particle size of 0.6 mm or more, the ash is crushed during compaction and piping 9 is densified without damaging it. Then, the backfill material 7 solidifies with time due to the action of the ash, and the pipe 9 is tightly protected. That is, it is possible to more reliably prevent the pipe 9 from being damaged by the load applied on the road as compared with the conventional backfill material made of only sand.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the ash and the other material for forming the underlayer such as the aggregate are mixed in advance, but may be mixed at the construction site.

Hereinafter, specific examples of the present invention will be described in detail.

(Example 1)

In a state where 5% to 7% by weight of water is added to the whole material, the roasting furnace ash, gravel (particle diameter: 3 mm to 12 mm), and slag (particle diameter: 2 mm or less) are mixed in a volume ratio of 2%. 0: 1.0: 0.5 was mixed by stirring to obtain a roadbed material A as a base material for civil engineering work.

The components of the roasting furnace ash were as shown in Table 1 below.

Next, after forming a lower subgrade having a thickness of 200 mm using a reclaimed crusher run (RC-40), the subgrade material A obtained as described above is spread over the lower subgrade, and the vibration compactor is used. To form an upper subgrade with a thickness of 150 mm.

Immediately after forming this upper subgrade, 1 ton and 2 tons are placed on the upper subgrade. The subsidence amount was measured by applying a load of 3 tons to the ground, and the ground reaction coefficient was obtained from the results.

(Example 2)

Subbase material B was obtained as a base material for civil engineering work in the same manner as in Example 1, except that sand (particle size: 2 mm or less) was used instead of slag.

Immediately after the upper subgrade was formed using this subbase material B in the same manner as in Example 1, 1 ton, 2 ton, and 3 ton load loads were applied to the upper subbase, and the settlement amounts were measured. The ground reaction force coefficient was obtained from the result.

(Example 3)

Example 1 After sprinkling water on the upper subgrade, 1 ton, 2 tons and 3 tons of load were applied to the upper subgrade 15 hours later to measure the amount of settlement, and the ground reaction force coefficient was determined from the results. .

(Example 4)

Example 2 After water sprinkling on the upper subgrade, a load of 1 ton, 2 tons and 3 tons was applied to the upper subgrade 15 hours later, and the amount of settlement was measured, and the ground reaction coefficient was calculated from the results. Was.

(Example 5)

The upper subgrade was formed in the same manner as in Example 1, except that the roadbed material A was compacted with a 4 ton roller instead of the vibration compactor. Immediately after that, 1 ton, 2 ton and 3 ton were loaded on the upper subgrade. The amount of settlement was measured by applying a load to the ground, and the ground reaction force coefficient was determined from the results.

(Example 6)

An upper subgrade was formed in the same manner as in Example 2 except that the subbase material B was compacted with a 4 ton roller in place of the vibration compactor. Immediately after that, 1 ton, 2 tons, and 3 tons were loaded on the upper subbase. The amount of settlement was measured by applying a load to the ground, and the ground reaction force coefficient was determined from the results.

(Example 7)

An upper roadbed was formed in the same manner as in Example 1 except that the roadbed material A was compacted with a 4 ton roller instead of the vibration compactor. Loads of 1 ton, 2 tons, and 3 tons were applied to the board, and the settlement was measured.

(Example 8)

An upper roadbed was formed in the same manner as in Example 2 except that the roadbed material B was compacted with a 4 ton roller in place of the vibration compactor, and 1 ton, 2 tons, and 3 tons were placed on the upper roadbed 15 hours later. The subsidence amount was measured by applying the load on the ground, and the ground reaction force coefficient was determined from the results.

(Example 9)

An upper subgrade was formed in the same manner as in Example 1 except that the subbase material A was compacted with a 4 ton roller instead of the vibration compactor, and water was sprayed on the upper subbase, and after 15 hours, the upper subbase was replaced on the upper subbase. The subsidence amount was measured by applying a loading load of 1 ton, 2 tons, and 3 tons, and the ground reaction force coefficient was obtained from the results.

(Example 10)

The upper subgrade was formed in the same manner as in Example 2 except that the subbase material B was compacted with a 4 ton roller instead of the vibration compactor, and water was sprayed on the upper subbase, and after 15 hours, the upper subbase was replaced on the upper subbase. The subsidence amount was measured by applying a loading load of 1 ton, 2 tons, and 3 tons, and the ground reaction force coefficient was obtained from the results.

(Example 11)

An upper subgrade was formed in the same manner as in Example 1 except that the subgrade material A was compacted with a 10 ton roller in place of the vibration compactor, and immediately thereafter, 1 ton, 2 tons, and 3 tons on the upper subgrade. The subsidence amount was measured by applying the loading load of, and the ground reaction force coefficient was calculated from the results.

(Example 12)

An upper subbase was formed in the same manner as in Example 2 except that the subbase material B was compacted with a 10 ton roller in place of the vibration compactor. Immediately thereafter, 1 ton, 2 tons, and 3 tons were placed on the upper subbase. The subsidence amount was measured by applying the loading load of, and the ground reaction force coefficient was calculated from the results.

(Example 13)

Press and compact roadbed material A with 10 ton roller instead of vibration compactor Otherwise, the upper subgrade was formed in the same manner as in Example 1, and after 15 hours, 1 ton, 2 ton, and 3 ton loading substrate loads were applied to the upper subgrade, and the settlement amounts were measured. The ground reaction force coefficient was determined.

(Example 14)

An upper roadbed was formed in the same manner as in Example 2 except that the roadbed material B was compacted with a 10-ton roller instead of the vibration compactor, and 1 ton, 2 tons, and 3 tons were placed on the upper roadbed 15 hours later. The subsidence amount was measured by applying the load of the loading board, and the ground reaction force coefficient was calculated from the results.

(Example 15)

An upper subbase was formed in the same manner as in Example 1 except that the subbase material A was compacted with a 10-ton roller in place of the vibration compactor, and water was sprayed on the upper subbase, and after 15 hours, the upper subbase was put on the upper subbase. The loadings of 1 ton, 2 tons and 3 tons were applied, and the amount of settlement was measured, and the ground reaction coefficient was calculated from the results.

(Example 16)

An upper subgrade was formed in the same manner as in Example 2 except that the subbase material B was compacted with a 10-ton roller in place of the vibration compactor, and water was sprayed on the upper subbase, and after 15 hours, the upper subbase was replaced on the upper subbase. The loadings of 1 ton, 2 tons and 3 tons were applied, and the amount of settlement was measured, and the ground reaction coefficient was calculated from the results.

(Comparative Example 1)

An upper subgrade was formed in the same manner as in Example 5 except that granulated crushed stone (M-30) was used in place of subbase material A. Immediately after formation, 1 ton, 2 ton, and 3 ton were placed on the upper subgrade. The subsidence amount was measured by applying the load on the ground, and the ground reaction force coefficient was calculated from the results.

Table 2 shows the settlement amount and ground reaction coefficient obtained in Examples 1 to 16 and Comparative Examples 1 and 2. The ground reaction force coefficient in the plate loading test was calculated by applying a load to a loading board with a diameter of 30 cm (loading board area A = 706.5 cm ² ) using a hydraulic jack and recording the sinking amount of the loading board. Then, from the result, it can be obtained by the following equation.

Ground reaction force coefficient (kgf / cm ³ ) = Load strength (kgf / cm ² ) Z settlement amount (cm) Load strength at 3 t load = 3 0 Okgf ÷ 7 0 6.5 cm ² = 4.2 6 4 kgf / cm ²

Table 2 clearly shows that the use of the roadbed material of the present invention can provide a strong roadbed required as the upper layer roadbed for the flat plate loading test, regardless of the type of compacting equipment. It is also clear that sprinkling water after forming the roadbed and leaving it for 15 hours increases the strength.

According to the ground survey method published by the Japanese Geotechnical Society, the amount of ground subsidence for calculating the ground reaction coefficient is 1.2 mm for concrete paved roads, railways and airport runways, and asphalt paved roads. Is 2.5 mm and the tank base is 5. Omm. When expressed this provision subsidence in 3 t of the load intensity to your Keru subgrade reaction coefficient ^{K 3 0 (kgf / cm 3} ), concrete paved roads, railways, ground reaction force coefficient airport runway 3 4. 0 kgf / cm ³ or more, and asphalt paved road 1 7. Okgf / cm ³ or more.

Therefore, as in the above Examples 1 to 16, when the foundation material for civil engineering work of the present invention is used as a roadbed material, the roadbed is effective not only for asphalt pavement but also for concrete paved roads, railways, and airport runways. It can be clearly seen that a can be formed.

(Example 17)

As shown in Table 3, particle size 2mm ~ 5mm, particle size 3mm ~: L 0mm, particle size 5mm ~ 15mm, particle size 15mm ~ 25mm, particle size 20mn! Roadbed materials were obtained by using five types of gravel of up to 30 mm and varying the ratio of roasting furnace ash, gravel, and sand as shown in Table 3. Using the obtained subbase material, an upper subbase was formed in the same manner as in Example 5, a flat plate loading test was performed, and the results are shown in Table 3.

From Table 3, the roadbed material is ash and 3 mn! Higher strength roadbed can be formed if coarse and fine aggregates with a particle size of about 10 mm are mixed in a ratio of ash: gravel: sand of 2.0: 1.0: 0.5. I understand.

(Example 18)

So that 5 0 kg / m ³ in the roadbed material A mixture of cement, road Board material c was obtained.

(Example 19)

Cement was mixed with the roadbed material A so as to be 100 kg / m ^3, and a roadbed material D was obtained.

(Example 20)

Cement mixed such that the 5 0 k gZm ³ above roadbed material B, to obtain a road board material E.

(Example 21)

The roadbed material B was mixed with cement so as to be 100 kg / m ³ to obtain a roadbed material F.

Using the roadbed materials C to F obtained in Examples 18 to 21 described above, an upper layer roadbed was formed in the same manner as in Example 5 above. The uniaxial compressive strength was measured 7 days after watering and 14 days after curing. The results are shown in Table 4.

According to Table 4, if cement is further added to the roadbed material, it is enough to spread and compact with a compacting device without forming a formwork as in the case of ready-mixed concrete. It can be seen that a roadbed with strength can be formed. In addition, since water was not added to the cement at the time of construction, there is no problem of solidification if the construction time is too long as in the case of ready-mix concrete, indicating that the workability is excellent.

Industrial applications

As described above, in the method for constructing a civil engineering underlayer according to the present invention, as the ash containing 15% by weight or more of calcium oxide is added to the underlayer forming material, the ash solidifies with time, It acts as a linking material for other underlayer forming materials such as aggregate, and can form a stable and strong underlayer.

In addition, if the foundation material for civil engineering work is laid on the foundation formation part with water, the ash will not be scattered by wind and the like, and the work environment at the construction site can be maintained well. Further, the ash can be densely filled to form a stronger underlayer.

As described above, the foundation material for civil engineering work according to the present invention Since ash such as incinerated ash is included in the components, ash can be recycled, eliminating the need for conventional ash landfill sites and reducing ash disposal costs. it can. In addition, the use of conventional base materials can be reduced, and material costs are also reduced. Moreover, since the ash contains 15% by weight or more of calcium oxide, a strong underlayer can be formed with time only by laying in a predetermined portion and compacting it. In addition, since mortar is not used, excavation can be easily performed at the time of repair, etc., and reuse is also possible. Furthermore, unlike conventional concrete, it does not solidify when the construction time is long, nor does it harden as cold as asphalt. Therefore, a strong underlayer can be easily obtained without being restricted by time.

Ash, coarse aggregate, and fine aggregate are blended in a volume ratio of 1.0 to 2.5: 0.75 to 1.5: 0.3 to 1.0. In this way, a strong roadbed can be obtained by using it as a roadbed material. If gravel is used as coarse aggregate and sand and / or molten slag is used as fine aggregate, pipes can be more strongly protected than conventional sand, etc. by using as backfill material.

By adding water to the ash, there is no scattering of particles such as ash 2 during construction, and the workability is excellent.

【table 1 】

Unit weight%

[Table 2]

Subsidence amount (mm) Ground reaction force coefficient What ¾ 0 Load 1 Load 2 Load 3 (gi / cm) t t t t

t ± r -kh- Example 1 丄 0.00 0.20 0.60 0.95 44.7 旲 2 0.00 0.25 0.70 1.00 42.4 Example 3 0.00 0.15 0.65 1.05 40.4 Actual ι ± τ 她 Example ta \ A

4 0.00 0.20 0.65 1.12 37.9 Example 5 0.00 0.18 0.45 1.05 40.4 Example 6 0.00 0.25 0.55 1.09 38.9 ι ^ tat n

Fushi 7 0.00 0.20 0.52 1.05 40.4 o u.uu Ό .20 U.bU l.Uo 39.3 Failure y 0.00 0.18 0.72 1.03 41 丄 .o Example 10 0.00 0.15 0.55 1.05 40.4 Example 11 0.00 0.28 0.50 0.89 47.7 Example 12 0.00 0.28 0.57 0.98 43.3 Example 13 0.00 0.22 0.48 0.84 50.5 Example '14 0.00 0.18 0.50 0.98 43.3 Example 15 0.00 0.25 0.52 0.91 46.6 Example 16 0.00 0.25 0.57 1.08 39.3 Comparative example 1 0.00 0.70 1.40 2.10 20.2 ΐ

【S 挲】 SZl / Z0df / X3d 0: 1.5: 1.0 to 5 0.00 0.80 丄 .95 o.Uo 13.9

0: 丄 .0: 1.0 o ~ 1U 0.00 0.65 1.30 Δ.ου 18.5 U: 1 o

.0: 1.U u.uu U.yo l 1.oU Δ. ΟΌ 14. y

2.0: 1.5: 1.0 15-25 0.00 1.00 1.85 2.87 14.8

2.0: 1.5: 1.0 20-30 0.00 1.05 2.05 3.05 13.9

[Table 4]

7 says 1 4 says

Roadbed material C 966KN / cm2 = 9.9kgf / cm2 1440KN / cm2 = 14.7kgf / cm2 roadbed material ^{D 1656KN / cm 2 = 16.7kgf /} cm2 2550KN / cm2 = 26.0kgf / cm2 roadbed material E 1017KN / cm2 = 10.4kgf / cm ² 1203KN / cm ² = 12.3kgf / cm ² Roadbed material F 2770KN / cm2 = 28.3kgf / cm ² 3130KN / cm2 = 31.9kgf / cm2

Claims

The scope of the claims

1. A method for constructing a civil engineering foundation layer, comprising laying a foundation material for civil engineering work containing at least ash containing at least 15% by weight of calcium oxide on a foundation formation part to form a civil engineering foundation layer.

2. The method for constructing a civil engineering foundation layer according to claim 1, wherein a foundation material for civil engineering work is laid on the foundation formation part with water.

3. The method according to claim 1 or claim 2, wherein the ground forming portion is a roadbed portion.

4. Substrates for civil engineering work that contain at least ash and aggregate containing at least 15% by weight of calcium oxide.

5. Ash, coarse aggregate, and fine aggregate are mixed at a volume ratio of 1.0 to 2.5: 0.75 to 1.5: 0.3 to 1.0. The foundation material for civil engineering work according to claim 4.

6. The base material for civil engineering work according to claim 5, wherein the coarse aggregate is gravel, and the fine aggregate is sand and / or molten slag.

7. The foundation material for civil engineering work according to claim 4, wherein the ash is in the form of a lump having a particle diameter of 0.6 mm or more, and the lump contains a lump of ash having a particle diameter of 0.6 mm or more and sand.

8. The foundation material for civil engineering work according to any one of claims 4 to 7, which contains water in advance.