KR100866012B1 - The composition for soil pavement and the construction method of soil pavement using thereof - Google Patents

Abstract

A soil pavement construction method is provided to suppress emission of generated CO2 gas from cement production, to reduce the cost from CO2 generation and to control air pollution. A composition for soil pavement comprises soil 50 ~ 90 weight%, mixed soil 65 ~ 90 weight% consisting of active filler 10 ~ 50 weight% which is the mixture of metakaolin and blast furnace slag, firming agent 10 ~ 35 weight% consisting of sodium silicate 75 ~ 91 weight%, the caustic potash 8 ~ 24 weight% and phosphoric acid kali 1 ~ 17 weight%. A soil pavement construction method comprises following steps: a step for preparing composition for the soil pave, a step for installing composition on basic layer, a step for hardening by using vibrating roller or compactor, a step for curing and solidifing with or without a curing tool.

Description

The composition for soil pavement and the construction method of soil pavement using the same

The present invention relates to an environment-friendly soil packaging composition and a method for constructing soil packaging using the same, and more specifically, it is a mixture of 50 to 90% by weight of soil such as masato, ocher, clay, and surface soil of mine and blast furnace slag and metakaolin. It consists of 65 to 90% by weight of compounded soil consisting of 10 to 50% by weight of active filler, 75 to 91% by weight of sodium silicate, 8 to 24% by weight of caustic cure and 10 to 35% by weight of solidifying agent of 1 to 17% by weight of phosphate Using the soil paving composition but preparing the soil paving composition; Laying the soil paving composition on a substrate; Compacting using a vibrating roller or a compactor; CSH and amorphous geopolymer matrix (GSH) inside the soil paving method consisting of the step of laying the curing device attached to the heating device such as electric blanket on the pavement surface and curing or curing and natural curing. Aluminosilicate gel (Al ₂ O ₃ · mSiO ₂ · nM ₂ O · xH ₂ O (M = K, Na, Ca)))) is solidified by the production of CO ₂ By suppressing the emission of gases, not only can the cost of CO ₂ generation by the Kyoto Protocol be reduced, but also the air pollution can be reduced, and the generation of Cr ⁶⁺ , which is toxic to cement, can be blocked at the source, causing environmental pollution. It can provide a pleasant environment not only for those who use the paved road but also for the contractor or the residents, and recycles a large amount of surface soil from mines. As you can protect nature and relates to the industrial by-products can achieve the effect of recycling to protect the environment, soil composition and soil pavement paving method using the same, such as blast furnace slag.

In general, road pavement is a road structure that is processed to enhance the protection and flatness of the road surface and to facilitate the passage of people and the driving of the vehicle. The road pavement is a multi-layered layer structure, and each layer shares its role.

Road pavement is classified into bitumen (asphalt) pavement, concrete pavement and block pavement according to the material of the surface layer. The bitumen pavement is the surface layer is composed of aggregate such as crushed stone by asphalt or tar. It is called as pavement, tar pavement, etc., and currently occupies most of the roads around the world.

Concrete paving is concrete laid on the surface layer. In addition to concrete or ordinary concrete paving with wire mesh in concrete, reinforced concrete paving, prestressed concrete paving, etc., block paving includes stone, brick, cement, Various blocks such as wood and asphalt are laid on the surface layer, and they are not used in the roadway at present, but are used for sidewalks and plazas.

Meanwhile, in recent years, a pavement method using environmentally friendly but not harmful to human body has been applied to bicycle roads and sidewalks. However, most soil pavement methods use cement or polymer as the main binder and use pozzolanic materials such as slaked lime, gypsum, limestone, blast furnace slag, fly ash, metakaolin, silica fume as additives to improve the function. have.

In addition, the conventional cement or asphalt-based pavement method has been installed in many fields with very easy workability and low price, but requires coal or petroleum to produce cement, and consumed coal and petroleum resources are combustion process Since limestone used to generate enormous CO ₂ gas and used as a raw material of cement is composed of CaCO ₃ is the main raw material to generate CO ₂ gas in the production of cement, there is a problem that the use of cement itself causes environmental pollution. That is, CO ₂ gas generated from cement production is one of the main causes of environmental pollution and air pollution.

In addition, the pavement layer by paving materials such as cement and asphalt is a pavement that disconnects the underground ecosystem and the surrounding ecosystem, and artificially prevents the release of beneficial substances from the soil, causing rare diseases. Recently, awareness of the reduction of cement usage is spreading internationally based on many environmental problems generated from such cements. For example, the concept of using a material that does not fire is introduced, and developed as an inorganic binder. Many non-cement materials are emerging. For example, there is a newly developed inorganic binder called geopolymer or mineral polymer or organic polymer. However, there is no packaging material developed by the geopolymer technique.

Cement reduction products and technologies are being developed in consideration of this shift in environmental and industrial awareness. For example, Patent No. 438138 describes a technique for limiting the range of natural soil, cement and solidification composition, and inducing excellent physical properties by controlling the size of particles. It has been described that the clay mixture, coarse sludge, coarse sludge, coarse soil, and clay powder are mixed with soil, expansion agent, water refining agent, soil mixture, cement and aggregate, and the resin is further densified. However, such a technique is still a technique that depends on the adhesion of the cement, it is almost ineffective in improving the environmental problems.

In addition, Patent No. 504987 describes soil reinforcement improving materials composed of admixtures such as fly ash or paper sludge, cement, pigment, slaked lime and silica fume in soil pavement construction. Patent Nos. 789877, 570958, and 581227. Many soil packaging patents, such as US Pat. No. 7,775,360 and the like, are a packaging technology that improves functions through additives to cement as described above.

Soil pavement is a paving material that people often use on the trails, parks, playgrounds, sidewalks, etc., it is preferable to use natural soil or environmentally friendly materials. In addition, natural damage or destruction for the construction of this packaging material is undesirable because it causes secondary environmental pollution. In addition, the soil-only packaging is often damaged by rainwater, the alternative to the alternative material of cement is still insufficient.

Accordingly, an object of the present invention is to solve the disadvantage that the packaging material using only soil is easily damaged, and to provide a durable earth packaging composition that does not use cement and is environmentally friendly and does not harm the human body.

Another object of the present invention is to provide a soil paving composition for neutralizing or weakly alkalizing acid soils by the soil paving composition and minimizing the destruction of the natural environment by recycling the blast furnace slag and the surface soil of the mine.

Another object of the present invention to provide an environmentally friendly earth paving method using the composition of the above object.

In order to achieve the above objects as well as yet another object that can be easily expressed in the present invention, active filler 10 which is a mixture of blast furnace slag and metakaolin with 50 to 90% by weight of soil such as masato, loess, clay, surface soil of mine, etc. For soil pavement consisting of 65 to 90% by weight of mixed soil consisting of 50% by weight, 75 to 91% by weight of sodium silicate, 8 to 24% by weight caustic and 1 to 17% by weight of phosphate Preparing a composition for paving soil using a composition; Laying the soil paving composition on a substrate; Compacting using a vibrating roller or a compactor; CSH and amorphous geopolymer matrix (GSH) inside the soil paving method consisting of the step of laying the curing device attached to the heating device such as electric blanket on the pavement surface and curing or curing and natural curing. the was allowed to solidify by being generated _{Aluminosilicate gel (Al 2 O 3 ·} mSiO 2 · nM 2 O · xH 2 O (M = K, Na, Ca)))).

The soil pavement according to the present invention can suppress the emission of CO ₂ gas generated during cement production due to the use of cement, not only can reduce the cost of CO ₂ generation by the Kyoto Protocol, but also reduce air pollution, cement It is possible to block the generation of toxic Cr ⁶⁺ at the source, so that it can provide a pleasant environment not only to people using the paved road but also to the contractor or residents, without causing environmental pollution. Recycling can be used to protect nature, and the industrial by-products such as blast furnace slag can be recycled to protect the environment.

Soil pavement composition according to the present invention 65 to 90% by weight of the mixed soil consisting of 50 to 90% by weight of the soil such as masato, loess, clay, surface soil of the mine and 10 to 50% by weight of the active filler is a mixture of blast furnace slag and metakaolin; It is characterized by consisting of 10 to 35% by weight of a solidifying agent consisting of 75 to 91% by weight of sodium silicate, 8 to 24% by weight of caustic chlorine, and 1 to 17% by weight of phosphate.

In addition, the soil pavement construction method according to the present invention is a mixed soil consisting of 50 to 90% by weight of the soil, such as masato, ocher, clay, surface of the mine, and 10 to 50% by weight of the active filler is a mixture of blast furnace slag and metakaolin 65 ~ Preparing a soil packaging composition composed of 90% by weight and 75 to 91% by weight of sodium silicate, 8 to 24% by weight caustic, and 10 to 35% by weight of a hardener comprising 1 to 17% by weight of phosphate; Laying the soil paving composition on a substrate; Compacting using a vibrating roller or a compactor; It is characterized in that it comprises the step of laying a curing device attached to a heating device such as an electric sheet on the pavement packed and cured or natural curing to solidify.

Soils used in the present invention are generally clays such as red mud (red clay) and ocher obtained from the surface of the earth, and sandy soils such as kaolin, white clay and masato, etc., and the type of soil is not particularly limited, but generally, It is preferable that the silt component having a particle diameter of 0.8 to 0.005 mm and the particles of fine granules and granules are suitably mixed in a ratio of 30%: 40%: 30%. In particular, in the present invention, the surface soil generated from the silica mine is mixed with the characteristics of various clay particles. The surface soil has a particle size of less than 212㎛ (average particle diameter is 50㎛) has a range of 30 ~ 50wt%, particles of more than 212㎛ ~ 2mm ranges from 50 ~ 70wt%, the viscosity and sand mixed properly There is a characteristic. In addition, although the composition of the chemical component phase of the soil is not specifically limited, the soil containing the composition as shown in Table 1 was used.

division SiO ₂ Al ₂ O ₃ CaO Fe ₂ O ₃ K ₂ O TiO ₂ MgO SO ₃ Na ₂ O soil 65.0 21.8 0.6 5.7 - - 1.1 - 0.4 Blast furnace slag 2 (6,000) 29.3 12.8 46.8 0.3 0.5 1.1 3.5 5.1 0.2 Metakaolin 52.6 38.1 4.8 1.4 0.7 0.2 1.1 - 0.7

Blast furnace slag is produced as a by-product when producing pig iron in the blast furnace, but is not particularly limited, but it is preferable to use a powder (Blaine) of 6,000 cm ² / g or more. In the present invention, 6,000 cm ² / g or more produced and sold from the Basic Materials Research Institute Co., Ltd. was used, and the composition including the composition as shown in Table 1 was used, although the composition of the chemical component phase was not particularly limited. If the powder is less than 6,000cm ² / g, whitening and cracking occurs during the construction of the soil, and the compressive strength of the packaging material decreases as the age of the old age decreases, resulting in long-term stability problems. There is a disadvantage that is difficult to apply to.

Unlike the soil composition, the blast furnace slag chemical composition is composed of SiO ₂ + Al ₂ O ₃ + CaO content of 88.6% by weight and other trace components of 11.4% by weight. Characteristically, the film of blast furnace slag is broken and the covalent bond between Si-O and Al-O constituting the particle is broken, so that Si ions and Al ions are leached to provide soil. Geopolymer consists of three-dimensional network structure of Na ₂ O, SiO ₂ and Al ₂ O ₃ , and dissolution (condensation) It is formed through polycondensation / polymerization process. Therefore, the composition of SiO ₂ and Al ₂ O ₃ present in the blast furnace slag serves as a major raw material source for producing geopolymers in the soil packaging composition of the present invention. In addition, the siliceous fertilizer component in the blast furnace slag is eluted by alkali and supplied to the soil, thereby reforming the acidified soil. The content of blast furnace slag is preferably 70 to 90% by weight based on 100% by weight of the active filler is a mixture of blast furnace slag and metakaolin. In the present invention, the main skeleton of the reaction is the blast furnace slag and the hardener causes the main reaction, metakaolin assists the reaction and serves as a filler. In particular, the blast furnace slag may play a major role in expressing initial strength because the reactivity of the blast furnace slag is superior to that of metakaolin in the reactivity. However, when blast furnace slag is added at less than 70% by weight, the particles are surrounded by the high-molecular weight of metakaolin and the reaction is suppressed. Therefore, it is difficult to exhibit sufficient physical properties, and when used in excess of 90% by weight, the price of metakaolin is economically high. Since it is more than 10 times of blast furnace slag, it is not only preferable in terms of physical strength or economical aspect, but also it is easy to generate bubbles due to rapid reactivity of blast furnace slag, and there is a problem such as crack generation in the long term due to generation of heat of hydration by CaO inside. Not.

Metakaolin is a heat treatment of natural kaolin at 700 to 750 ° C. The present invention does not specifically limit the composition of the chemical component, but includes a composition as shown in Table 1 below. Metakaolin is mixed with blast furnace slag and serves as a filler to assist the blast furnace slag. The powder of metakaolin is more than 12,000cm ² / g and is ocher color, and it is filled in the gap between the particles to make the hardened body have a dense structure, and it has excellent amorphousness and is a raw material of geopolymer like blast furnace slag. Used. In particular, unlike blast furnace slag, metakaolin contains 38.1% of Al ₂ O ₃ in a very high content, and thus has an advantage of easily inducing a geopolymerization reaction in preparing a geopolymer material. In addition, since it is ocher color, it is possible to exhibit a natural earthy color without adding a pigment when constructing the soil. The average particle size is about 30 μm as shown in FIG. 1, and the particle size distribution is filled with fine and fine grains. This is excellent and improves the fluidity of aggregate particles contained in the soil. In addition, metakaolin, as well as blast furnace slag when 97% of SiO ₂ and Al ₂ O ₃ are mixed with a solidifying agent, is further subjected to a geopolymerization reaction, which is a leaching-condensation-condensation polymerization in the soil packaging composition. It acts to exert a strong bond. The content of metakaolin is preferably 10 to 30% by weight based on 100% by weight of the active filler which is a mixture of blast furnace slag and metakaolin. When added at less than 10% by weight, it is difficult to form a sufficient geopolymeric matrix due to the filler effect and lowering of element supply effects of SiO ₂ and Al ₂ O ₃ , which are the main components of the geopolymer, and exceeds 30% by weight. When added, there is a problem in that the high powder of the added metakaolin suppresses the reaction while surrounding the blast furnace slag, and the initial strength is significantly lowered.

When the amount of active filler consisting of blast furnace slag and metakaolin exceeds 50% by weight or the amount of soil used is less than 50% by weight, there is a disadvantage in that the advantages of soil pavement are not expressed, and the activity consisting of blast furnace slag and metakaolin If the amount of the filler is less than 10% by weight or the amount of the soil is more than 90% by weight, the construction of the pavement is not easy and the strength of the pavement surface is deteriorated.

The solidifying agent used in the present invention is the use of a strongly alkaline atmosphere (pH 13 or higher) composition for inducing a geopolymerization reaction. And the one of sodium silicate, the main agent composition of SiO ₂ and Na ₂ O and K ₂ O caustic Kariya of geo polymer are shown in Figure 2 the main skeleton of [Si ^4+], and [Na ^+] To provide a cation of [K ⁺ ]. In addition, the OH ^- silver of the hardening agent breaks the blast furnace slag film and breaks the covalent bond between Si-O and Al-O to induce an ion elution reaction, and the eluted ions are separated between the soil particles and the blast furnace slag and metakaolin particles. It forms a three-dimensional framework and forms a geopolymeric matrix in the soil pavement composition. In this case, when the curing temperature is 80 ° C. or more, a zeolite and a geopolymer matrix are simultaneously formed.

The solidifying agent used in the present invention is composed of 75 to 91% by weight of sodium silicate, 8 to 24% by weight caustic and 1 to 17% by weight of phosphate, and the pH is lowered to about 11 when only sodium silicate is used. There is a problem that the geopolymer reaction is very quick because the alkali active reaction does not occur. In addition, when only caustic carry is used, it is possible to cause geopolymer reaction because it is very high at pH 14 or higher, but it is necessary to add very high concentration of KOH because it cannot supply 100% of ions to generate geopolymer from blast furnace slag and metakaolin. If this is the case, further measures are required to lower the pH even after soil packing, which adds to the cost. In addition, high concentrations of pH change soil liquids to strong alkalis, which can adversely affect microorganisms and underground ecosystems. Caustic added is also included in the role of suppressing the addition of the phosphate, so the soda silicate is sharply lowered to precipitate sodium silicate. The amount of caustic carry used is 8 to 24% by weight, and it is preferable to use 45% industrial caustic carry. When the amount of caustic carries is less than 8% by weight, it is difficult to dissolve completely when caric phosphate is added, and precipitates of sodium silicate remain.When it is added in excess of 24% by weight, the pH of the carbophosphate is completed after soil packing is completed. It takes a long time to lower the time to 10.5 or less.

On the other hand, the phosphoric acid phosphorus acts to suppress the reaction to prevent the reaction of sodium silicate and caustic with blast furnace slag or metakaolin for a certain time to secure workability, improve the water resistance of sodium silicate, and in the soil packaging composition It promotes the consumption of excess OH ^- ions to lower the pH to the range of 9.0 ~ 10.5. It is preferable to use the phosphate in the range of 1 to 17% by weight, and if it falls outside the above range, it cannot serve as PO ₄ ^-3 . The added PO ₄ ^-3 ions react with CaO, one of the main components of blast furnace slag to form Ca ₃ (PO ₄ ) ₂ , which inhibits the reaction of alkali-activated slag, The concentration of [Ca ²⁺ ] ions eluted to the surface is reduced to facilitate the generation of a geopolymer matrix.

  In the present invention, the sodium silicate used in the solidifying agent may be potassium silicate, lithium silicate, lithium sodium silicate, and the like, and caustic carry may be caustic soda, caustic calcium, caustic lime, and the like. , Phosphoric acid, magnesium phosphate, aluminum phosphate, zinc phosphate, ammonium polyphosphate and the like can be used, and sodium silicate, caustic and phosphate are not particularly limited.

Preparing an earth packaging composition configured as described above; Laying the soil paving composition on a substrate; Compacting using a vibrating roller or a compactor; On the pavement surface, a curing device with a heating device such as an electric blanket is installed and cured or cured by natural curing to perform soil pavement construction.

In the soil pavement construction method using the soil pavement composition of the present invention, the soil pavement composition may be blended according to the above-described composition ratio of dry, semi-dry and wet.

The soil preparation composition preparation step, laying step, compaction step is a method that can be uniformly and completely construction of the soil packaging, is not particularly limited, can be applied by selecting a method commonly used in the art to which the present invention belongs. have.

Curing of the surface layer after the compaction in the soil pavement construction using the soil pavement composition is cured at a temperature of 25 ~ 80 ℃, natural curing is possible in the summer season, but in the period except summer season to promote hardening for fast walking and passage In order to cover the surface layer using commercially available curing cloth or vinyl, it can be cured by using steam or hot air, and more preferably, drying mats (roller type, far-infrared rays) sold by Century Century Co., Ltd. Using a film for heating 80 ℃ heating) can be kept warm for 4 hours or more at 60 ℃ to enable walking after 1 day.

Soil pavement construction method using the soil pavement composition of the present invention neutralizes the acidic soil by adding blast furnace slag and metakaolin to the soil, blocking the harmfulness of the existing cement, and forming a geopolymer having the same crystal structure as zeolite And weak alkalizing is possible, and by curing by the geopolymerization reaction, a packaging base having a compressive strength of 10 to 30 MPa can be obtained.

1 is a particle size distribution curve of metakaolin used in the present invention,

2 is a photograph showing the structure of a geopolymer.

Claims (5)

50 to 90% by weight of at least one soil selected from the group consisting of masato, ocher, clay, and mine surface soil, and 10 to 50% by weight of active filler which is a mixture of blast furnace slag and metakaolin; A soil packaging composition comprising 75 to 91% by weight of sodium silicate, 10 to 35% by weight of a caustic agent, and 8 to 24% by weight caustic and 1 to 17% by weight of phosphate. The composition of claim 1, wherein the active filler comprises 70 to 90 wt% of blast furnace slag and 10 to 30 wt% of metakaolin. The soil paving composition of claim 1 or 2, wherein the blast furnace slag has a powder degree of 6,000 cm ² / g or more, and the metakaolin has a powder degree of 12,000 cm ² / g or more. Soil pavement method consists of 50 to 90% by weight of at least one soil selected from the group consisting of masato, ocher, clay, and surface soil of mine and 10 to 50% by weight of active filler which is a mixture of blast furnace slag and metakaolin. Preparing a soil packaging composition composed of 65 to 90% by weight, 75 to 91% by weight of sodium silicate, 8 to 24% by weight caustic, and 10 to 35% by weight of a hardener comprising 1 to 17% by weight of phosphate; Laying the soil paving composition on a substrate; Compacting using a vibrating roller or compactor; A method of paving soil comprising the steps of laying a curing device with a heating device on the pavement surface, and curing or curing with natural curing. The soil pavement construction method according to claim 4, wherein the curing is performed at a temperature of 25 to 80 ° C.

Images