JPH0123601B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for reinforcing a ballast track in which a cement asphalt mortar layer reinforced with long-fiber mat is provided in the space formed on the ballast track bed, the lower surface of the sleepers, and the surrounding area of the ballast track. Ballast track is the type of track that occupies most of the conventional railway lines, and its structure consists of a ballast bed on the roadbed, and sleepers and rails on top of it. The structure absorbs the load and vibration energy caused by passing trains by deforming the ballast. When rain falls on the ballast track, the rainwater percolates and softens the roadbed beneath the track bed, causing the ballast track bed to sink. In addition, over time, the surface of ballast tends to wear down and become finer due to the effects of train loads, vibrations, and rainwater, and when rainwater is added to these finer grains, it becomes muddy soil, which is deposited between the stones of the ballast. This causes the ballast trackbed to sink and the ballast to solidify, causing major orbital deviations. For this reason, it is necessary to plan and carry out regular track maintenance work on ballast tracks, such as replenishing new ballast, screening or replacing ballast to remove fine particles, and correcting track deviations. BACKGROUND ART In recent years, with the increase in transportation volume, railways have been forced to increase the speed of running vehicles and increase the amount of vehicles passing on many routes, including major trunk lines. On the other hand, in terms of track structure, in order to ensure economy and safety, it has been advocated for a long time to strengthen railway tracks and save labor, and for this purpose, slab tracks have been developed, and new lines such as the Shinkansen have been built. It is used for lines. Even with conventional ballasted tracks, there is a demand for the development of tracks that can save labor in track maintenance, that is, reduce track maintenance work, and ensure safe transportation. Paved tracks have been developed to meet these demands. It was done. Paved track is mainly intended for conventional lines, and the sleepers and upper ballast of the existing ballast track are removed, the remaining ballast surface is compacted, and large sleepers (referred to as LPC) are arranged there. A gap of approximately 20mm is created between the bottom surface of the LPC and the top surface of the ballast, and heated and molten special asphalt is injected into the gap to fill the gap and permeate into the top of the ballast. , solidifying the ballast around the LPC. Furthermore, the track bed surface is paved with a cutback asphalt mixture. However, in this method, heated and molten asphalt is injected, so there are risks due to the time required for heating and melting and the use of fire.In winter, when asphalt is injected, the asphalt cools down quickly. As a result, the asphalt may not penetrate sufficiently into the required areas and may solidify during the process.In addition, in the summer, the temperature of the heated asphalt injected is slow to drop, resulting in a longer time for strength development, resulting in construction management issues. It has some difficult points. The present invention can save labor in track maintenance work on ballast tracks, and also solves the difficulties caused by injection of heated asphalt on paved tracks.
Because it is constructed at room temperature, reliable construction is possible regardless of the season, and we provide a method for reinforcing ballast tracks constructed with room-temperature filling material by interposing long-fiber pine in the necessary solidified layer. It is something to do. That is, the present invention provides, in the ballast orbit,
A filled space is formed between the ballast bed and the underside of the sleeper and around the sleeper, long fiber pine is interposed in the filled space, and cement and bituminous emulsion (hereinafter referred to as CA mortar) are applied to the long fiber pine. The gist of this method is to strengthen the ballast track by injecting filler into the filler space to cover the fibers and hardening the filler. The ballast track reinforcement method of the present invention will be explained using figures. FIG. 1 is a plan view showing an outline of a ballast track strengthened by the construction method of the present invention, and FIG. 2 is a sectional view of FIG. 1. In the figure, 1 is a ballast trackbed, 2 is a sleeper, 3 is a CA mortar injection port provided on the sleeper 2, and 4 is a rail. 5 is a filling space on the lower surface of the sleeper 2 and its surroundings. Reference numeral 6 denotes a barrier layer, which is provided on the trackbed ballast facing the charging space 5. Numeral 7 is long fiber mat, which fills the filling space 5. 8 is a CA mortar made by mixing cement and bituminous emulsion, as well as aggregate, admixture, water, etc. as required. 9 is a reinforced roadbed such as concrete, and 10 is a waterproof surface pavement. The ballast track strengthening method of the present invention will be explained step by step with reference to FIGS. 1 and 2. First, the ballast located above the ballast trackbed 1 is removed to create a charging space 5. The ballast surface of the filling space 5 is leveled and compacted. This filling space 5 ensures a uniform thickness on the lower surface of the sleeper 2. A barrier layer 6 is provided on the ballast surface in contact with the charging space 5. This barrier layer 6 prevents the CA mortar 8 from seeping into the ballast excessively when the CA mortar 8 is injected into the filling space 5,
Provided to form 8 layers of CA mortar with an average and uniform thickness. Various types of barrier layer 6 can be used as described below. The thickness of the filling space 5 is about 2 to 10 cm on the lower surface of the sleeper 2, and usually about 5 to 6 cm. Therefore, long fiber mat 7 is laid in the filling space 5 on and around the lower surface of the sleeper 2. If necessary, the amount of long fiber mat 7 is increased to reinforce areas where stress is concentrated. Next, CA mortar 8 is injected into the filling space 5 from the injection port 3 of the sleeper 2. The CA mortar 8 fills the gaps between the fibers of the long fiber mat 7, covers the fibers, and fills the filling space 5 without any gaps. After this CA mortar 8 has hardened, a waterproof surface pavement 10 is applied to the surface of the ballast track bed 1, thereby completing a ballast track strengthened by the construction method of the present invention. Next, materials used in the construction method of the present invention will be explained. The long fiber mat 7 used in the present invention includes glass fiber, polyester, polyamide, polyimide, aromatic polyamide, polypropylene, vinylon, acrylic, polyvinylidene chloride, synthetic fiber such as polyvinyl chloride, carbon fiber, metal fiber, etc. Non-directional fibers, such as single fibers, strands of many single fibers bundled with a sizing agent, continuous fibers such as single threads, twisted threads, and twisted threads, or those cut into lengths of at least 30 mm or more are usually non-directional. The fibers are piled up to form a mat of appropriate thickness. Some of these mat-shaped materials are partially treated with binding materials or needle punches to prevent the fibers from falling apart, while others are not treated with these methods. Can be used. Since the thickness of the filling space 5 changes depending on the finishing accuracy of the compacted ballast surface, these long fiber mats 7 are preferably bulky so that they can be sufficiently pushed into the recesses and supported as a whole. . A typical long fiber mat 7 is a mat made by stacking continuous fibers of glass fiber strands in a bulky manner. CA mortar 8 used in the present invention, namely:
A known cement asphalt mortar made by mixing cement and bituminous emulsion with aggregate, admixture, water, etc. can be used. That is, conventional techniques are used for the materials, compositions, etc. that constitute these. Examples of materials include cement such as Portland cement, fly ash cement, blast furnace cement, silica cement, blast furnace colloidal cement, colloidal cement, jet cement, alumina cement, and sulfate-resistant cement. These may be used alone or in combination. Along with these cements, admixtures such as cement shrinkage compensators, hardening accelerators, hardening retarders, AE agents, dispersants, thickeners, water reducers, blowing agents,
Antifoaming agents and the like can also be used together. The bituminous emulsion is made of one kind or a mixture of two or more kinds selected from petroleum asphalts such as straight asphalt, blown asphalt, semi-blown asphalt, and broban deasphalt, natural asphalts, tars, pitches, etc. Bituminous materials, or bituminous materials modified by adding and mixing rubber, synthetic polymers, etc. surfactant,
Bentonite is used as the main emulsifying agent, and if necessary, emulsifiers, dispersants, stabilizers, protective colloids, etc. are used as appropriate to emulsify it in water, or these bituminous emulsions are mixed with rubber latex, synthetic polymers, etc. It is a mixture of a combined emulsion, a synthetic resin emulsion, a water-soluble polymer, a water-soluble synthetic resin, etc. Furthermore, a mixture of a water-soluble or emulsified epoxy resin and a reactive resin such as a curing agent for the epoxy resin can also be used. Generally, asphalt-based bitumen emulsions are used. The concentration is such that the evaporation residue is 55-70% by weight, and the penetration of the evaporation residue (25℃) is 30-30%.
About 400 are used. The aggregate is fine aggregate. The fine aggregate has a grain size of 2.5 mm or less, and a coarse grain ratio in the range of 1 to 2.5. Examples include river sand, sea sand, mountain sand, silica sand, sintered ash sand, iron sand, and foundry sand. In addition to aggregate, we also produce glass powder, silica sand powder, diatomaceous earth, mica powder, mica pieces, bentonite, clay, stone powder, fly ash, silica anhydride powder, pigments, carbon black,
A filler such as graphite can be used. These can also be used after being dispersed in water. Furthermore, colloidal silica can also be used. As water, fresh water is generally used. That is, tap water, industrial water, groundwater, river water, etc. CA mortar 8 contains 1 part by weight of cement (hereinafter simply referred to as part), 0.1 to 5 parts of bituminous emulsion (converted to 60% by weight of evaporation residue), and aggregate (as sand).
It is used in a proportion of 0 to 6 parts, usually 0 to 2 parts. When using cement shrinkage compensators, hardening accelerators, etc., include them in the amount of cement in the above mixing ratio. Water is used appropriately considering the workability of CA mortar 8. When using a blowing agent,
For example, when using aluminum powder,
Although it varies depending on the amount of bubbles introduced into the CA mortar 8, it is generally used in a range of 0.005 to 0.02% by weight based on the amount of cement. The amount of long fiber mat 7 to be used in CA mortar 8 is such that the amount of fibers is in the range of 0.2 to 5% by volume based on the volume of CA mortar 8. The larger the amount of long fiber mat 7 used, the more the reinforcing effect of the fibers can be exhibited, and the tensile strength, bending strength, flexibility, impact resistance, etc. can be improved. However, if it exceeds 5% by volume, the filling of the CA mortar 8 into the gaps between the long fiber mats 7 becomes poor. Moreover, when it is less than 0.2% by volume, the reinforcing effect of the long fiber mat 7 cannot be sufficiently exhibited. Reinforcement with the long fiber mat 7 can also be performed intensively. For example, the reinforcing effect can be further improved by increasing the amount used in areas where stress is concentrated. The following materials can be used for the blocking layer 6. Nonwoven fabrics, woven fabrics, knitted fabrics, reticulated fabrics, mesh made of natural fibers, synthetic fibers, plastics, etc.
In addition to netting, gold netting, etc., bituminous tarpaulin sheets,
Rubber waterproof sheets and plastic waterproof sheets can also be used. Alternatively, the compaction barrier layer 6 can be formed by crushing the rough surface of the ballast surface and spreading crushed stone, fine aggregate, filler, rubber powder, etc. thereon. In addition, a thin layer of paving with a mixture of cold-applying bitumen emulsion or cutback asphalt, surface treatment with a penetrating bituminous emulsion, and paving with a heated asphalt mixture (for example, asphalt concrete) can be applied on the ballast surface to form a barrier layer 6. It is also possible to do this. Further, the barrier layer 6 can be formed by spreading a rubber latex asphalt emulsion sealing material applied at room temperature on the ballast surface, or the barrier layer 6 can be formed by spreading heat-injected rubber asphalt. In addition, the various barrier layers described above may be combined to form a barrier layer 6.
It is also possible to do this. The waterproof surface pavement 10 can be the same as the conventional one. Next, the features and effects of the ballast track reinforcement method of the present invention will be explained. (1) The underside of the sleepers is reinforced with long fiber pine.
By providing a CA mortar layer, train load,
It is possible to create a ballast track structure with excellent performance against vibration, shock, shear force, etc. In addition, the CA mortar layer reinforced with long fiber pine
Its excellent waterproof properties prevent rainwater from entering the ballast, preventing softening of the roadbed and mud blowing. (2) CA mortar layer reinforced with long fiber pine
Compared to conventional CA mortar alone and short fiber-reinforced CA mortar, the inventors' experiments have shown that performance such as impact resistance, flexibility, and strength is several steps higher. (3) Because construction is performed at room temperature, there is no time required to heat and melt the asphalt and there is no danger associated with the use of fire compared to heating methods. In addition, it can be installed throughout the year, regardless of the dryness or humidity of the ballast.
By selecting the CA mortar composition, the required strength development time can be adjusted. From the above, the reinforced ballast track constructed by the construction method of the present invention uses CA mortar reinforced with long-fiber pine to reliably form the necessary solidified layer on the underside of the sleepers. etc. can be prevented. Therefore, track maintenance work such as ballast replacement work can be significantly reduced. Next, the experimental results regarding the physical properties of long fiber pine-reinforced CA mortar will be shown, comparing a single CA mortar and a premix type in which short fibers are mixed into CA mortar with a CA mortar containing short fibers. [Materials used in the experiment] Cement: Jet cement (trade name) manufactured by Onoda Cement Co., Ltd. Asphalt emulsion: Emulsion A (trade name) manufactured by Nichirei Kagaku Kogyo Co., Ltd. Asphalt emulsion evaporation residue for nonionic cement mixing 60 Weight% Penetration of evaporation residue 109 Fine aggregate: Toride river sand FM: 1.56 Water: Tap water Aluminum powder: Nakajima Metal C-250 Long fiber pine: Asahi Glass Co., Ltd. Continental Strand Pine CSM (product name) 600g/ ^m2 Alkali-resistant glass fiber strands are piled up in a pine-like shape so that they are continuously entwined without cutting. Short fibers (length 12 mm): Made by Asahi Glass Co., Ltd. Alkali-resistant glass fiber Chiyo Tup strand 12mm in length [Test method] (1) Flow time According to the draft prepact concrete guidelines stipulated by the Japan Society of Civil Engineers. Measure the flow time using a J funnel. (2) Compressive strength and bending strength test Comply with JIS R 5201 "Physical test method for cement". Loading speed: 1 mm/min (3) Impact test Use a Page impact tester. Size of specimen: 5cm x 10cm x 10cm Place a plunger (tip diameter: 2cm) on top of the specimen.
A spherical body weighing 1 kg) was placed on top of the plunger, and an iron mallet (weight 2.4 kg) was dropped from a height of 1 m. Measure the number of drops until cracks appear on the specimen. Experiment 1 The composition of CA mortar and the kneading composition are shown in Table-1.

[Table] Using a mortar mixer (standard rotation speed 150 times/min, variable speed type), put the asphalt emulsion, water, antifoaming agent, and diet setter into the mortar mixer and mix at 115 times/minute for about 1 minute. Add jet cement and mix at 150 times/min for about 1 minute.
Next, add fine aggregate and aluminum powder to 115
Mix once/minute. 10 minutes, 20 minutes, 30 minutes after kneading
Measure the flow time after minutes. Table the results.
Shown in 2.

[Table] Preparation of long fiber pine reinforced CA mortar specimens,
and test Long fiber mat (approx. 2 cm thick) was cut into 4 x 16 cm pieces, and this was placed in a mold for making the specimen (4 x 4 x 16 cm).
cm) so that the amount of fibers is 1.0% by volume (% outside) of the CA mortar, inject and fill the above CA mortar into this mold, harden it, and make the long fiber pine reinforced CA Mortar was made and compressive strength and bending strength were measured. In the bending strength test, even when the maximum load was reached, the bending progressed, but no cracking occurred, so the test was terminated. The impact test was performed using a formwork (specimen size: 5 cm x 10 cm x 10
After cutting and inserting the required amount of long fiber pine in the same way into a 1.5 cm (cm) space, CA mortar was injected and filled, allowed to harden, and a specimen was made and subjected to an impact test. As a result, no deformation was observed in the specimen even after 60 impact tests. The material age for the test on the specimen was 28 days. These test results are shown in Table-3. Furthermore, the condition of the specimen immediately after the impact test is shown in FIG. 31. Also, Figure 4 shows
FIG. 5 shows the relationship between bending strength and displacement, and FIG. 5 shows the relationship between compressive strength and displacement. In addition, CA mortar with a standard blend without adding fibers, and CA mortar with short fibers in which short fibers (glass fiber chop strands, length 12 mm) are premixed with the CA mortar (the order of addition of fibers is as follows:
Add asphalt emulsion, water in that order, then add other materials) (Fiber addition amount 0.6% by volume (% outside))
A specimen for comparison was prepared in the same manner as in the experimental example, and tested in the same manner as in the experimental example. The result is
Table-3, Figure 3 2 and 3, Figure 4, and Figure 5
Also shown in the figure.

【table】 [Brief explanation of drawings]

In the drawings, FIG. 1 shows an embodiment of the ballast track reinforcement method according to the present invention, and is a plan view of a reinforced ballast track. FIG. 2 is a cross-sectional view of FIG. 1. Figures 3 1, 2, and 3 are all plan views of the test specimens showing the results of the impact tests. Figure 3 2 shows that the specimen of experiment number 2 (comparative example) was broken in half after eight impact tests, and Figure 3 3 shows that the specimen of experiment number 3 (comparative example) This shows that cracks were generated in the specimen of example) after 28 impact tests. FIG. 4 is a bending strength-displacement curve diagram in a bending strength test. FIG. 5 is a compressive strength-displacement curve diagram in a compressive strength test. The symbols in the figure are explained as follows. 1
is the roadbed ballast, 2 is the sleeper, 3 is the sleeper injection port, 4 is the rail, 5 is the filling space, 6 is the barrier layer, 7 is the long fiber pine, 8 is the CA mortar, 9 is the reinforced roadbed such as concrete, 10 Has a waterproof surface paving.

Claims (1)

[Scope of Claims] 1. In the ballast track, a filled space is formed between the ballast track bed and the lower surface of the sleeper and around the sleeper, long fiber pine is interposed in the filled space, and cement and bituminous emulsion are added to the length of the filled space. A method for reinforcing ballast tracks characterized by injecting filling into the filling space to cover the fibers of fiber pine and hardening it. 2. Cement and bituminous emulsion are used as aggregate, admixture,
Claim 1, characterized in that it is a cement asphalt mortar mixed with water etc.
Ballast track reinforcement method described in Section 1.