KR20020013459A - Method of restoration about digging of paved road - Google Patents

Abstract

PURPOSE: A paved road excavation-restoration method is provided to shorten the speed of construction works and to recycle resources without subsidence after constructing. CONSTITUTION: A paved road excavation-restoration method comprises the steps of: mixing more than one of clinker powder, a high-early-strength composite, ultra-rapid-hardening cement, high-early-strength cement and ultra-early-strength cement with soil from an excavation work of a paved road evenly(S200); manufacturing slurry by adding and mixing a blended water to the admixture(S300); and filling the slurry to an excavated part and curing the surface(S400).

Description

Method of restoration about digging of paved road}

The present invention relates to a pavement excavation recovery method, and more particularly, compared to the existing pavement excavation restoration construction is faster construction speed, environmentally friendly and economical excavation that recycles resources without any settlement after construction To a recovery method.

In the excavation and recovery work on the pavement, after the pipeline or underground burial is installed, the soil is refilled with soil or sand. When carrying out excavation restoration work on the pavement, the excavation restoration method is standardized due to difficulties in traffic communication, complaints of residents around the construction site, narrowness of underground excavation space, and defects occurring after construction.

In the case of Korea, the Ministry of Construction and Transportation, Seoul and other local cities entered the 1990s to expand and maintain social indirect facilities, and to recover after excavation, such as expanding roads, installing and replacing water pipes, and filling voids after installing underground structures. (Backfilling, compaction, repackaging) are being carried out nationwide.

Currently, in Korea, pavement excavation and reconstruction works have been set up to begin construction at midnight and finish around 6 am in order to smooth traffic and minimize inconvenience of nearby residents. Therefore, it is very insufficient in time to carry out high-quality construction in the process of excavation restoration construction that must be completed quickly. Even if the construction time is absolutely insufficient and the excavation cross section is narrow, the foundation of the pipe and the pledge of soil is inadequate, and even if the compaction is made, additional settlement occurs due to the nature of the soil. It is a cause of shortening the life of the packaging and the life of the buried pipe.

Existing methods for compaction recovery using excavated soil or sand have been as follows.

① Difficulty of resolution

After laying soil excavation, foundation bedding (bedding refers to the work of leveling soil or concrete before the pipe is installed to maintain the level of the pipe), and backfilled with excavated soil or sand, etc. Compaction at the optimum water content is practically impossible, and the working space is narrow, so that compaction equipment cannot be thoroughly compacted to a narrow corner.

② Settlement and pavement cracking after compaction

Even if the soil is thoroughly compacted after being disturbed, a lot of time must elapse in order to exhibit the inherent strength and density due to the strength recovery of the soil. For these reasons, settlement occurs after excavation recovery, cracks on the surface of the road, and the entire road is damaged, causing a lot of budget and repaving.

③ Breakage of pipes or buried structures during compaction

Excessive compaction to ensure compaction will cause damage to the bottom pipe or buried underground structure due to compaction energy and should be rebuilt.

④ Construction time

Excavation and reconstruction works are mainly carried out by night to reduce traffic problems and inconvenience to residents around the construction site. However, there is an absolute shortage of construction time, which provides a cause for the deterioration of the quality of excavation and recovery work.

As one of the methods for solving the above-mentioned problems, as shown in FIG. 1, sand or the like is filled in the excavation recovery method of forming an auxiliary base layer made of coarse aggregate and a granular layer made of fine aggregate. This is because the excavation recovery layer is made of several layers of different materials, so the compaction density is not sufficiently secured during pavement recovery, and the settlement of the road surface after the traffic is still occurring. The back is filled with sand, but still sinking, and the cost is high, so it is not economical compared to the existing soil refilling method.

Therefore, the technical problem to be achieved by the present invention is to solve the problems as described above, the construction speed is faster than the existing pavement excavation restoration construction, environmentally friendly and economical recycling resources without any settlement after construction It is to provide a recovery method for phosphorus.

1 is a recovery cross-sectional view according to the conventional pavement excavation recovery.

2 is a flow chart of a pavement excavation recovery method implemented in accordance with the present invention.

3 is a cross-sectional view of a pavement excavation recovery in accordance with the present invention.

In order to achieve the above technical problem, the present invention

(a) any one or more selected from the group consisting of clinker powder composed mainly of calcium sulfoaluminate minerals, crude composition composed mainly of calcium sulfoaluminate minerals, cemented carbide, crude cement and crude cement; Mixing uniformly with soil generated in the excavation work on the pavement;

(b) adding a blended water to the mixture and mixing to prepare a slurry; And

(c) providing the excavation recovery method to the pavement comprising the step of filling and curing the slurry in the excavated portion.

In the above-mentioned pavement excavation restoration method according to the present invention, the coarse-grained composition containing the calcium sulfoaluminate mineral as a main component is 10 to 60% by weight of clinker powder containing calcium sulfoaluminate mineral as a main component, Portland Cement 5 It is preferably composed of 30 to 30% by weight, quicklime or slaked lime 10 to 40% by weight, 5 to 40% by weight of natural anhydrous gypsum, and 0 to 5.0% by weight of a siliceous salt.

In the above-mentioned pavement excavation recovery method according to the present invention,

The content of soil sand in the mixture of step (a) is preferably 55 to 95% by weight. That is, a mixture of any one or more selected from the group consisting of clinker powder composed mainly of calcium sulfoaluminate minerals, crude composition composed mainly of calcium sulfoaluminate minerals, cemented carbide, crude cement, and crude cement It is preferred to mix to 5 to 45% by weight of the total.

In the above-mentioned pavement excavation restoration method according to the present invention, it is preferable to further prepare a slurry by adding a surfactant at the time of slurry preparation in step (b).

Soil from excavation is placed in a certain place, and after laying the pipeline, clinker powder mainly composed of calcium sulfoaluminate mineral, crude composition mainly composed of calcium sulfoaluminate mineral, cemented carbide, crude cement and crude Excavation restoration method according to the present invention as described above to recover the excavation site using a mixture of any one or more selected from the group consisting of steel cement is to fill the voids generated when the soil or sand backfill after excavation It is fully charged to prevent uneven settlement due to continuous load after recovery of excavation, and it is economical because it can reduce the use of sand used for backfilling by reusing the soil without reusing it. Reuse without throwing away soil It is an environmentally friendly way to maximize the use of limited resources by curbing its use, and drastically reduce maintenance costs by preventing uneven settling of roadbeds, roadbeds, and pavement layers, which is the biggest problem in maintenance of pavement roads. It has the advantage to do it.

Hereinafter, with reference to Figure 2 which is a flowchart of the excavation recovery method according to the present invention will be described in detail.

First, clinker powder containing calcium sulfoaluminate-based minerals mixed with earth and sand generated in excavation work, a roughening composition mainly composed of calcium sulfoaluminate-based minerals, cemented carbide, crude cement or ultra-light cement are prepared. (S100).

The cemented carbide cement, crude steel cement or cemented cement is well known in the art to which the present invention pertains. In the present invention, the ready-made product can be used as it is, and the crude steel cement has a fast hydration rate of about 28 days. It has the characteristics of good strength in low temperature and low temperature, and the roughened steel cement has a cement mineral composition with high hydration activity at the early stage. In addition, cemented carbide cements 7-day strength of ordinary cement in 2 ~ 3 hours and has better roughness than alumina cement.

In addition, the crude composition mainly composed of the calcium sulfoaluminate mineral (hereinafter referred to as "crude composition") is specifically calcium sulfoaluminate mineral, portland cement, quicklime or hydrated lime, natural anhydrous gypsum, silica fluoride salt Consists of the characteristics and actions of each component as follows.

The calcium sulfoaluminate mineral is a clinker containing at least 60% by weight of 3CaO ₃ Al ₂ O ₃ CaSO ₄ component. The calcium sulfoaluminate-based mineral reacts with portland cement, quicklime or hydrated lime and anhydrous gypsum upon hydration to form ettringite or monosulfate, thereby making the roughing composition fast. Calcium sulfo aluminate powder, grain size of the carbonate-based mineral is capable of 3,000-6,000cm ² / g in Blaine specific surface area, and most preferably 4,000 ± 500 cm ² / g. Such a specific surface area of the blain affects the initial reaction rate. The higher the specific surface area, the faster the reaction rate.

Natural anhydrous gypsum has a slower dissolution rate compared to hemihydrate gypsum and dihydrate gypsum, which is suitable for reactivity with calcium sulfoaluminate minerals and contributes to the stability of high strength and solidified soil bodies. The natural anhydrous gypsum reacts with calcium sulfoaluminate mineral, quicklime or hydrated lime to form ettringite, and the amount thereof is determined by the amount of calcium sulfoaluminate mineral, quicklime or hydrated lime, preferably The weight ratio of calcium sulfoaluminate mineral / anhydrite is less than 1 and less than 3, and 2.5 ± 0.1 is best. This ratio of calcium sulfoaluminate mineral / anhydrite has an effect on stability (dimension stability) and durability at long-term age and contributes to the development of high strength. Natural anhydrous gypsum used in the roughening composition according to the present invention is type II anhydrous gypsum, the powder degree is 3,000-8,000cm ² / g of the specific surface area of the brain.

Quicklime or hydrated lime not only contributes to strength development by generating hydrates by pozzolanic reactions, but quicklime reacts and generates heat in the early stages, and reduces the water content of soil by forming calcium hydroxide to secure initial strength and prevent cracking by dry shrinkage. Since it is a helpful component, it is more advantageous to use quicklime than slaked lime.

Silica fluoride promotes hydration reaction with calcium sulfoaluminate minerals from the time of hardening and accelerates the dissolution rate of silica (SiO ₂ ) and alumina (Al ₂ O ₃ ) components that are eluted from the soil for a long time. It accelerates the reaction and contributes particularly to high strength at early age. As the silicide salt of the additive for soil concrete of the present invention, K ₂ SiF ₆ , MgSiF ₆ , NaSiF ₆ may be used, and among these, K ₂ SiF ₆ has the most significant effect.

The composition ratio of the earth and sand roughness composition component having the above characteristics is 10 to 60% by weight of clinker powder based on calcium sulfoaluminate mineral, 5 to 30% by weight of Portland cement, 10 to 40% by weight of quicklime or slaked lime, natural Anhydrous gypsum is preferably 5 to 40% by weight, and 0 to 5.0% by weight of silicide fluoride.

Characteristic reactions occurring in the crude composition of the present invention having the above constituents are as follows.

① Ettlingite creation

Ettlingite has a large amount of water as the binding water, thereby lowering the water ratio to constrain the movement of soil particles and make it possible to bond. Since the crude composition of the present invention contains a silofluoride salt, the production of a large amount of ettringite is promoted.

② pozzolanic reaction

The addition of siliceous salts not only promotes the production of ettringite, but also accelerates the pozzolanic reaction with the soil, allowing rapid curing and high strength.

③ aggregation of soil particles

Initially large amounts of calcium ions eluted from Portland cement, quicklime, or slaked lime aggregate soil particles.

The strength expression mechanism of the crude composition is classified into three stages of improvement effect of the soil itself, hydration reaction due to additives, and reactions of the components and additives available in the soil. The mechanism of strength expression is as follows.

The method of increasing the soil strength by incorporating the coarse stiffness composition is all about improving the physical properties of the soil and curing by pozzolanic reaction, so that sufficient strength, water content decrease, ion exchange stop, plasticity index reduction, hydrate formation hardening, and ecringite formation It is possible to achieve breakthrough strength through various chemical and physical reactions such as (networking of soil) and soil particle confinement.

Next, any one selected from the group consisting of clinker powder mainly composed of calcium sulfoaluminate-based minerals as described above, crude composition composed mainly of calcium sulfoaluminate-based minerals, cemented carbide, crude cement, and crude cement Mixing one or more homogeneously with the soil generated in the excavation work (S200).

In this step, any one or more selected from the group consisting of clinker powder composed mainly of calcium sulfoaluminate mineral, crude composition composed mainly of calcium sulfoaluminate mineral, cemented carbide, crude cement, and cemented cement The amount of usage depends on the characteristics of the soil, the required strength after recovery, the location and time of excavation restoration work, but the compressive strength is about 3 hours after the excavation site is filled in order to complete the excavation restoration work within one day. 10 kgf / cm ² , and after about 24 hours, it is increased to about 30 kgf / cm ² , and in order to maintain the compressive strength thereafter, it is preferably about 5 to 45 wt% based on the total weight of the mixture of the S200 step. After 24 hours, the compressive strength increased to about 30kgf / cm ² , and the reason why the compressive strength is maintained thereafter is that if the compressive strength becomes too high, it is difficult to re-excavate after completing the excavation restoration work. to be.

In the present invention, the mixing method of step S200 is not particularly limited, but a general method of premixing each component of the crude composition and adding and mixing the target soil is used and should be homogeneously mixed.

Subsequently, the mixture is added to the mixture of step S200 and mixed to prepare a slurry (S300).

Mixing water should not affect the quality of concrete due to the incorporation of foreign substances such as oil, acid, organic matter, etc. In general, water quality that can be used as drinking water is preferable, and the amount of mixing water can be appropriately used considering the fluidity of the slurry. .

This is because when the slurry is completely filled up to the corner of the excavation site where the fluidity of the slurry should be good, it is possible to prevent inequality due to continuous load after the excavation recovery. In the present invention, a surfactant may be further added to increase the fluidity of the slurry. have.

The surfactant is to form a lubricating film between the particles to reduce the mutual adhesion between the components to show an improved flow characteristics, for example, the usable surfactants, such as melamine based superplasticizer , Naphthalene based superplasticizer, polycarboxyl acid based superplasticizer, and lignosulphonate based superplasticizer.

After filling and curing the slurry of the step S300 to the last step and the curing method according to the invention is completed (S400).

When filling the slurry, it is necessary to properly adjust the feed rate at the site so that the laying pipe does not rise due to the input pressure of the slurry. In addition, the slurry can be easily poured into the excavation site as well as the fluidity as well as compaction. The parts that have been difficult to penetrate into themselves form a perfect fill and do not need to be compacted.

According to the excavation recovery method according to the present invention shows a strength of about 10kgf / cm ² when cured for about 3 hours can exhibit sufficient strength for concrete or asphalt pavement, and also about 30kgf / cm ^{2 after a} long time Since it does not increase because it can be easily re-excavated with a shovel or excavation equipment, it has a feature that can be re-excavated if the boss is required again after installing the pipe.

Next, the present invention will be described in detail through examples. The following examples are only for illustrating the present invention, and it is obvious that the present invention is not limited to these examples.

Examples and comparative examples to be described later are for construction to recover after drilling the depth of 1,700mm, width 1,000mm, 500mm in diameter, embedded in a 10,000mm length pipe.

<Example 1>

Soil produced from excavation was 1.62 tons of solidified homogeneously mixed at a ratio of 30% by weight of calcium sulfoaluminate, 25% by weight of gypsum free, 35% by weight of quicklime, 9% by weight of ordinary Portland cement and 1% by weight of siliceous salt. About 20 tons).

Subsequently, the mixture was added to the mixture and mixed to form a slurry, which was then filled in the excavated portion and cured for about 3 hours, followed by paving with asphalt to complete the construction. Excavation recovery cross-sectional view according to this embodiment is shown in FIG.

Comparative Example 1

In the present comparative example, as shown in FIG. 1, the hearth and the furnace body are filled with sand, and after the auxiliary base layer made of coarse aggregate and the granular layer made of fine aggregate are formed on the upper portion thereof, the asphalt is paved for a sufficient time so as not to settle down. After the compaction work, asphalt pavement was completed.

In Example 1 and Comparative Example, the construction period, economics, and the like are shown in Table 1 below.

Item Comparative example Example Remarks construction period 10 days 1 day Asphalt paving Soil Waste 15.44m ³ (23.16 tonne) 2.64m ³ (3.96 tons) Earth and sand processing costs (KRW) 463,200 79,200 20,000 won / ton Strength after 3 hours (kgf / cm ² ) Compaction construction in progress 10 Compressive strength Sand usage 8.44m ³ (12.66 tonne) none Assumed sand height 1m Sand purchase costs (KRW) 253,200 none 20,000 won / ton Roughness composition usage none 1.62 tons Roughness composition cost (KRW) none 486,000 300,000 won / ton Total cost 716,200 565,200 Difference: KRW 151,000

As shown in Table 1, it can be confirmed the economics of the present invention by showing a considerable difference in terms of money in the embodiment according to the present invention and the comparative example according to the conventional method, the construction period is also shortened from 10 days to 1 day the present invention The effect is very large.

<Example 2>

Excavation restoration work was carried out in the same manner as in Example 1, except that superhard cement (Tongyang Cement, trade name: Super Cement) was used instead of the coarse-grained composition mainly composed of calcium sulfoaluminate-based minerals.

In the case of the present embodiment, the compressive strength was measured when about 3 hours had elapsed after filling the slurry composed of cemented carbide, earth and sand, and water for the excavation site, and the strength was about 10 kgf / cm ² . Therefore, in the case of this embodiment, it was found that the pavement excavation restoration work is sufficient to complete within one day.

<Example 3>

Example 1 described above, except that crude steel cement (Ssangyong Co., Ltd., a product satisfying the specifications of three types of crude steel portland cement of KS L 5201) was used in place of the crude composition mainly composed of calcium sulfoaluminate-based minerals. Excavation and recovery work was carried out in the same way.

In the case of the present embodiment, the compressive strength was measured when about 3 hours had elapsed after filling the slurry consisting of crude cement, earth and sand, and the excavation site, and the strength was about 10 kgf / cm ² . Therefore, in the case of this embodiment, it was found that the pavement excavation restoration work is sufficient to complete within one day.

<Example 4>

Excavation restoration work was carried out in the same manner as in Example 1, except that superelastic steel cement (ssangyong ash) was used in place of the coarse-grained composition mainly composed of calcium sulfoaluminate-based minerals.

In the case of the present embodiment, the compressive strength was measured when about 3 hours had elapsed after filling the slurry composed of the roughened steel cement, the earth and sand, and the excavation site, and the strength was about 10 kgf / cm ² . Therefore, in the case of this embodiment, it was found that the pavement excavation restoration work is sufficient to complete within one day.

The excavation restoration method according to the present invention as described above is completely filled with voids generated when the earth or sand backfilling after excavation to prevent unequal settlement due to the continuous load after the excavation recovery, without discarding the soil generated during excavation It is economical by reducing the use of sand used for backfilling by reusing it, and it is economical. It is an environmentally-friendly way to maximize the use of limited resources by restoring the use of sand without discarding excavated soil. The main problem in the maintenance of the pavement road is to prevent the uneven settlement of the furnace body, the roadbed, the pavement layer, etc., which occurs during the backfill after excavation has the advantage of significantly reducing the maintenance cost.

Claims (4)

(a) any one or more selected from the group consisting of clinker powder mainly composed of calcium sulfoaluminate minerals, crude composition composed mainly of calcium sulfoaluminate minerals, cemented carbide, crude cement, and crude cement Mixing uniformly with soil generated in the excavation work on the pavement; (b) adding a blended water to the mixture and mixing to prepare a slurry; And (c) filling and curing the slurry in the excavated portion; and excavation recovery method comprising the step of curing. The method of claim 1, The crude composition mainly composed of calcium sulfoaluminate minerals includes 10 to 60% by weight of clinker powder based on calcium sulfoaluminate minerals, 5 to 30% by weight of Portland cement, 10 to 40% by weight of quicklime or slaked lime, natural 5 to 40% by weight of anhydrous gypsum, 0 to 5.0% by weight of a silicate salt excavation recovery method. The method of claim 1, The excavation recovery method on the pavement, characterized in that the content of soil sand in the mixture of step (a) is 55 to 95% by weight. The method of claim 1, Method for recovering excavation road pavement, characterized in that further adding a surfactant at the time of slurry production of step (b).