KR102450046B1 - Road pavement structure with salt damage resistance - Google Patents

Abstract

The present invention relates to a salt-resistant road pavement structure which comprises: a pavement layer which includes asphalt, styrene-ethylene-butylene-styrene, inorganic filler, mesophilic additive, sulfur powder, and inorganic fiber; and a surface layer which is applied to the surface of the pavement layer, and includes asphalt emulsion, cement, inorganic filler, styrene-ethylene-butylene-styrene, carrageenan, and lignin sulfonate.

Description

Road pavement structure with salt damage resistance

The present invention relates to a salt-resistant road pavement structure.

In general, since the state of asphalt changes greatly according to temperature changes, the asphalt pavement produced thereby also has severe behavior changes according to changes in temperature. Asphalt pavement used for road pavement due to this temperature sensitivity causes plastic deformation due to ductility in a high-temperature environment in summer and cracks due to brittleness in a low-temperature environment in winter.

On the other hand, calcium chloride is mainly used to prevent freezing in the winter, which is useful as a snow remover by absorbing moisture in the snow and causing an exothermic reaction to melt the surrounding snow and lower the freezing point.

However, as calcium chloride melts in a weak part of the road pavement and cars pass through this part repeatedly, the asphalt corrodes and settles, or the water that seeps into the asphalt freezes and melts and expands repeatedly, causing the road to be damaged, so-called potholes. There is a serious problem of hole formation.

In order to solve these problems, a method of modifying asphalt using a polymer is proposed. As a polymer mainly used for asphalt modification, a rubber-based styrene-butadienestyrene (SBS) copolymer or an artificial latex styrene-butadiene rubber ( Styrene-butadiene rubber (SBR) is a typical example.

However, such asphalt reforming using SBS and SBR is effective in resolving problems such as plastic deformation and fatigue cracking of road pavement, but as mentioned above, salt damage caused by calcium chloride for snow removal is not sufficiently solved. there is

Korean Patent Registration No. 10-0788248

The present invention has been devised to solve the above problems, and it is to provide a salt-resistant road pavement structure having high resistance to chlorides such as calcium chloride, and in addition to improving other physical properties such as water resistance and strength.

As a means for solving the above problems, the salt-resistant road pavement structure of the present invention (hereinafter referred to as "the pavement structure of the present invention") includes asphalt, styrene ethylene butylene styrene, inorganic fillers, medium temperature additives, sulfur powder, and inorganic fibers. a packaging layer; It is applied to the surface of the pavement layer and includes a surface layer containing asphalt emulsion, cement, inorganic filler, styrene ethylene butylene styrene, carrageenan, and lignin sulfonate, and a coating layer containing sodium alginate is applied to the surface of the inorganic fiber do it with

As an example, the inorganic filler includes trimite, silicon dioxide, and dolomite.

As an example, the dolomite is characterized in that the magnesium carbonate film is formed inside and outside by reacting with a gas containing carbon dioxide.

As an example, the packaging layer is characterized in that it further includes a mixture of inorganic waste sludge powder and sulfites that are by-product in the soda ash production process.

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As described above, the pavement structure of the present invention has an advantage in that it has high resistance to chlorides such as calcium chloride and at the same time has high physical properties such as water resistance, crack resistance, and strength.

1 is a cross-sectional view showing the pavement structure of the present invention.

Hereinafter, the configuration and operation of the present invention will be described in more detail based on the accompanying drawings. In describing the present invention, the terms or words used in the present specification and claims are based on the principle that the inventor can appropriately define the concept of the term in order to best describe his or her invention. It should be interpreted as meaning and concept consistent with the technical idea of

As shown in FIG. 1, the pavement structure 1 of the present invention includes a pavement layer 2 comprising asphalt, styrene ethylene butylene styrene, an inorganic filler, a medium temperature additive, sulfur powder, and inorganic fibers; It is applied to the surface of the pavement layer and the surface layer (3) containing asphalt emulsion, cement, inorganic filler, styrene ethylene butylene styrene, carrageenan, and lignin sulfonate; characterized in that it comprises a.

Preferably, the pavement layer (2) comprises 5 to 10 parts by weight of styrene ethylene butylene styrene, 5 to 10 parts by weight of inorganic filler, 0.01 to 1 part by weight of medium temperature additive, 0.01 to 1 part by weight of sulfur powder, based on 100 parts by weight of asphalt, It is appropriate to blend in an amount of 0.01 to 1 part by weight of inorganic fibers.

In addition, the surface layer 3 is 10 to 30 parts by weight of cement, 5 to 10 parts by weight of inorganic filler, 1 to 5 parts by weight of styrene ethylene butylene styrene, 0.01 to 1 parts by weight of carrageenan, and lignin sulfonate based on 100 parts by weight of the asphalt emulsion. It is appropriate to be formulated in an amount of 0.01 to 1 part by weight.

The type of asphalt is not limited, but BRA (Buton Rock Asphalt) or TLA (Trinidad Lake Asphalt) may be applied, for example. BRA (Buton Rock Asphalt) or TLA (Trinidad Lake Asphalt) has a lower flexural strength coefficient than general asphalt, so when it is applied to steel deck, it is dependent on the behavior of the steel deck, and problems such as lifting of the joint surface are controlled.

The styrene-ethylene butylene styrene (Stylene isoprene stylene; SEBS) copolymer is a styrene-butadiene-styrene block copolymer (SBS) resin with excellent stability in which all double bonds in the butadiene of the resin are saturated by hydrogenation, and elasticity is added. can do.

In addition, since the styrene-ethylenebutylene-styrene copolymer is not thermally decomposed, there is no fear of odor harmful to the human body, the elastic recovery force and permanent deformation resistance are improved, and durability and abrasion resistance are also expressed.

The inorganic filler is intended to express salt resistance and water resistance, and in particular, in the present invention, examples in which trimite, silicon dioxide, and dolomite are included as inorganic fillers are presented.

The addition of trimite not only improves the salt decomposition resistance, but also enhances strength and waterproofness.

In addition, silicon dioxide and dolomite are further added to the inorganic filler, which is to solve the problem of lowering water resistance due to lower moisture sensitivity than the heated asphalt mixture in the case of the asphalt mixture to which the medium temperature additive is added, as described below.

The silicon dioxide functions and serves to increase resistance to temperature change and humidity change by reducing thermal conductivity and reducing temperature deviation.

In addition to this, dolomite is included to impart water resistance to the paste, and the dolomite reacts with silicon dioxide to impart water resistance to water.

That is, a mixture of silicon dioxide and dolomite is added to the inorganic filler, and silicon dioxide improves the stability of the paste against changes in humidity. will make it so

As a result, even if sufficient moisture is not removed from the aggregate during the mixing process of the medium-temperature asphalt mixture, stability is obtained by silicon dioxide against humidity changes due to exposure to such moisture, and in addition to the moisture exposed by the reaction of silicon dioxide and dolomite This is to improve the water resistance of the paste.

In addition to this, the present invention provides an example in which water resistance is doubled by mixing modified dolomite to improve reactivity with silicon dioxide.

In the present embodiment, the dolomite reacts with a gas containing carbon dioxide to include modified dolomite formed inside and outside the magnesium carbonate film.

Dolomite has pores inside and outside. Modified dolomite reacts dolomite particles with a gas containing carbon dioxide so that a film of magnesium carbonate is applied inside and outside dolomite. It is to supply a gas containing carbon dioxide to the furnace to form a film of magnesium carbonate on the surface and inside by diffusion.

As described above, the film is formed to generate magnesium carbonate (MgCO ₃ ) in the internal and external pores of the dolomite to double the reactivity with silicon dioxide, thereby improving water resistance as described above.

It is reasonable to mix 20 to 50 parts by weight of silicon dioxide and 20 to 50 parts by weight of dolomite with respect to 100 parts by weight of trimite as the inorganic filler.

The medium temperature additive is to lower the temperature required for the manufacture and/or construction of the asphalt binder by about 20 to 40° C., thereby minimizing the emission of carbon dioxide and harmful substances.

Various known materials may be applied as the medium temperature additive, for example, polyethylene wax may be applied. The polyethylene wax preferably has a melting point of 90 to 130°C, and a melting viscosity of 80 to 300cPs at about 130°C.

When the melting point of the polyethylene wax is less than 90 ℃, the strength of the asphalt may be weakened when mixed with the asphalt, and when the melting point exceeds 130 ℃, uniform dispersion is not made and non-uniform physical properties may be expressed. will be.

The sulfur powder is such that functions such as plastic deformation and fatigue crack resistance increase are expressed. As the sulfur powder, natural sulfur derived from mines may be used as a general sulfur element, but the amount of sulfur generated during desulfurization during the refining process of domestic oil refinery plants reaches about 1.5 million tons per year, and securing and usability of mass demand. It is preferable to use sulfur generated during the refining process of an oil refinery plant, an industrial by-product, in view of a situation where there is a limit to the increase.

In addition, although not mentioned above, aggregate is further included in the pavement layer 2, and in general, the quality or particle size of the aggregate has a great influence on the performance of the pavement, and the physical-chemical properties are different depending on the production area. In general, coarse aggregate means the aggregate remaining in the 2.5mm (No. 8) sieve, while fine aggregate means the aggregate remaining in the 0.08mm (No. 200) sieve after passing through the 2.5mm sieve.

Here, the coarse aggregate is crushed aggregate (crushed stone), crushed slag, crushed gravel, and the like, and preferably does not contain harmful substances such as clay, silt, and organic matter (refer to KS F 2357 standard). Fine aggregate is crushed sand (screenings) obtained by breaking rocks and gravel, natural sand, or a mixture thereof, and preferably does not contain harmful substances such as dust, clay, and organic matter (refer to KS F 2357 standard).

The inorganic fibers are intended to improve crack resistance through crosslinking action, and inorganic fibers have superior compressive strength or tensile strength compared to organic fibers, so they do not break even under high pressure (500kg/20sq.cm) and impact, and have elasticity. It not only maintains it, but also enables self-healing.

These inorganic fibers are not limited in their type, but for example, glass wool, basalt, ceramic wool, etc. may be applied.

On the other hand, a medium-temperature additive is added to the pavement layer 2, and since the aggregate is heated at a lower temperature than that of the conventional heated asphalt mixture, there is a limit in removing moisture present in the aggregate in the process of preparing the asphalt mixture.

As a result, the asphalt mixture to which the medium temperature additive is added has lower moisture sensitivity than the heated asphalt mixture, so the cohesion and adhesion between the aggregate and the asphalt are weakened by the water flowing into the asphalt pavement. cause tally. This phenomenon, that is, the phenomenon that the asphalt flows down from the aggregate is called a "drain-down" phenomenon, and this phenomenon causes the problem of the aggregate to be detached from the asphalt after construction.

Accordingly, in the present invention, the inorganic fiber uses a modified inorganic fiber coated with a coating layer containing sodium alginate on the surface. It will control the drain-down phenomenon.

That is, the inorganic fiber coated with a coating layer containing sodium alginate doubles the force holding the asphalt from the aggregate to control the drain-down phenomenon. In addition, sodium alginate absorbs moisture contained in the aggregate, thereby controlling the factors that decrease the water resistance of the binder due to such moisture.

The sodium alginate has a carboxyl group as one of the polysaccharides, and can be made by treating kelp with soda ash. Sodium alginate has a property of expressing viscosity when in contact with water.

The coating layer containing the sodium alginate may be a coating layer by a mixture containing a surfactant and sodium alginate.

In addition, the pavement layer 2 may contain a mixture of inorganic waste sludge powder and sulfite that is by-product in the soda ash production process. Preferably, it is reasonable to mix 2 to 15 parts by weight of the mixture with respect to 100 parts by weight of asphalt. .

The inorganic waste sludge powder produced by the soda ash production process is composed of sodium chloride and potassium carbonate as the main raw materials, and the inorganic waste sludge discharged from the plant producing soda ash (Na ₂ CO ₃ ) is sedimented and washed with water to be included in the sludge. It is manufactured by removing about 70% of the chlorine group (Cl ^- ), drying it at a predetermined temperature, and grinding it through a mesh of a predetermined size.

Such inorganic waste sludge powder is a material with a small specific gravity but high strength and does not expand even when heat is applied to improve the strength of asphalt. will be.

However, when only the inorganic waste sludge powder is used, the strength can be reinforced to some extent. However, the inorganic waste sludge powder contains a chlorine group (Cl ^- ) component that acts as an inhibitor of strength enhancement, so it can be used to reinforce asphalt strength. There are limits.

Accordingly, in the present invention, a mixture of inorganic waste sludge powder and sulfite is added to the filler. The sulfite promotes the decomposition of chlorine group (Cl ⁻ ) components from inorganic waste sludge powder by decomposition action and makes it immobilized with solid zinc chloride through hydrogen chloride, thereby inactivating chlorine group (Cl ⁻ ) as a strength inhibiting factor. .

Preferably, it is appropriate that the inorganic waste sludge powder and the sulfite are mixed in a weight ratio of (95:5) to (99:1).

The surface layer 3 is applied to the surface of the pavement layer 2 and includes asphalt emulsion, cement, inorganic filler, styrene ethylene butylene styrene, carrageenan, and lignin sulfonate. By allowing (3) to be applied, it not only doubles the salt damage resistance, but also allows the effects such as waterproofness, abrasion resistance, and porthole prevention to be expressed.

The asphalt emulsion is obtained by stably dispersing asphalt using a surfactant.

The surfactant functions as an emulsifier, and depending on the type, a cation-based, anion-based, or nonionic-based surfactant may be applied.

The type of cement is not limited, but it is preferable to use a fast-hardening cement.

The carrageenan is a thickening stabilizer to control material separation, low viscosity, and the like.

The lignin sulfonate is to improve the effect of curing time dependent on temperature.

Since the inorganic filler and the styrene ethylene butylene styrene are the same as those described above, a detailed description thereof will be omitted.

Hereinafter, preferred embodiments of the present invention will be described by way of experimental examples.

<Production of specimen for packaging layer>

After preheating while stirring the asphalt, 5 parts by weight of styrene ethylene butylene styrene, 0.05 parts by weight of a medium temperature additive, 0.05 parts by weight of sulfur powder, and 0.1 parts by weight of basalt fiber are sequentially added with respect to 100 parts by weight of the asphalt, and the stirring temperature is increased to 140 ° C. A modified asphalt binder was prepared by maintaining and stirring for 30 minutes, and 20 parts by weight of the modified asphalt binder was mixed with 100 parts by weight of aggregate (including stone powder) to prepare an asphalt mixture while maintaining 140°C.

Here, in Example 1, pure basalt fibers were added to the modified asphalt binder, and in Example 2, basalt fibers coated with a sodium alginate coating layer were added.

In addition, Example 3 is the same as in Example 2, except that 10 parts by weight of the inorganic filler is further added based on 100 parts by weight of the asphalt, and the inorganic filler is trimite, silicon dioxide, and dolomite mixed in a weight ratio of 1:0.2:0.2 by weight. Example 4 is the same as Example 3 except that modified dolomite in which dolomite reacts with a gas containing carbon dioxide to form a magnesium carbonate film inside and outside was used, Example 5 is the same as Example 4, except that asphalt 5 parts by weight of inorganic waste sludge powder were mixed with respect to 100 parts by weight, Example 6 was the same as Example 5, except that 5 parts by weight of inorganic waste sludge powder and nitrite mixture (99:1 by weight) were mixed did it

The following experiment was performed with six specimens as shown above, and the results are shown in Tables 1 and 2.

sample situation Stability (N) Example 2 before immersion 19,811 after immersion 16,911 Example 3 before immersion 19,909 after immersion 19,898

For the evaluation of salt resistance, each of Example 2 and Example 3 was immersed in salt water with a salt concentration of 3.5% (w/v) for 7 days, and then the degree of change in stability before and after salt water immersion was measured using a KS F 2337 Marshall tester. did.

As shown in Table 1, in the case of Example 3, trimite, silicon dioxide, and dolomite were further added as inorganic fillers compared to Example 2, and in Example 3, there was little change in the stability value before and after immersion in brine. it can be seen that

In contrast, in the case of Example 2, it can be seen that there is a decrease in stability before and after immersion in salt water. That is, it can be seen that the resistance to chloride is improved by the addition of trimite, silicon dioxide, and dolomite, especially trimite, as inorganic fillers.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Water resistance (%) 59 65 73 78 79 78 Crack resistance (N) 19,650 19,790 19,910 19,980 19,920 19,970 Dynamic stability (times/mm) 910 970 975 970 985 990 Compressive strength (MPa, 28 days) 69 70 76 77 81 85

Water resistance (aggregate coverage after dynamic water immersion, %) was based on the EN-12697-11 Determination of the affinity between aggregate and bitumen test method. The Marshall stability and flow value test method of the asphalt mixture used was used as a standard, and the dynamic stability was measured by applying a force of 6.4kg/cm2 of ground pressure to a specimen of 300mm×300mm×50mm at 60℃ according to the wheel tracking test (KS F 2374) method. The number of reciprocations per dent depth (times/mm) was measured, and the compressive strength was measured using an asphalt compressive strength tester.

As shown in Table 2, it can be seen that Example 2 is superior to Example 1 in dynamic stability, which is that in Example 2, a basalt fiber coated with sodium alginate on the surface is used to drain down as mentioned above. It is thought to be due to the control of the phenomenon.

In addition, it can be seen that Example 3 exhibits a superior effect than Example 2 in terms of water resistance, which is believed to be due to the fact that, as mentioned above, in the case of Example 3, a mixture of silicon dioxide and dolomite is further included as an inorganic filler. , It can be seen that Example 4 exhibits a better effect in terms of water resistance than Example 3, which is judged to be due to the addition of modified dolomite to facilitate the reaction of silicon dioxide and dolomite as mentioned above. do.

In addition, it can be seen that Example 5 exhibits an excellent effect than Example 4 in terms of compressive strength. It can be seen that a more excellent effect is expressed in terms of compressive strength than in Example 5. This is because the inorganic waste sludge powder contains more nitrite to inactivate chlorine groups (Cl ^- ) contained in the inorganic waste sludge powder. is considered to be due to

Those skilled in the art from the above description will be able to see that various changes and modifications are possible without departing from the technical spirit of the present invention. Accordingly, the technical scope of the present invention is not limited to the content described in the detailed description of the specification, but should be defined by the claims.

2: packaging layer 3: surface layer

Claims (5)

a pavement layer comprising asphalt, styrene ethylene butylene styrene, inorganic fillers, medium temperature additives, sulfur powder, and inorganic fibers;
a surface layer applied to the surface of the pavement layer and comprising asphalt emulsion, cement, inorganic filler, styrene ethylene butylene styrene, carrageenan, and lignin sulfonate;
Salt-resistant road pavement structure, characterized in that the coating layer containing sodium alginate is applied to the surface of the inorganic fiber.
The method of claim 1,
Salt-resistant road pavement structure, characterized in that the inorganic filler includes trimite, silicon dioxide, and dolomite.
3. The method of claim 2,
The dolomite reacts with a gas containing carbon dioxide to form a magnesium carbonate film inside and outside the salt-resistant road pavement structure.
delete The method of claim 1,
Salt-resistant road pavement structure, characterized in that the pavement layer further comprises a mixture of inorganic waste sludge powder and sulfite that are by-produced in the soda ash production process.

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