CA2112612A1 - Ballast stabilizer - Google Patents
Ballast stabilizerInfo
- Publication number
- CA2112612A1 CA2112612A1 CA 2112612 CA2112612A CA2112612A1 CA 2112612 A1 CA2112612 A1 CA 2112612A1 CA 2112612 CA2112612 CA 2112612 CA 2112612 A CA2112612 A CA 2112612A CA 2112612 A1 CA2112612 A1 CA 2112612A1
- Authority
- CA
- Canada
- Prior art keywords
- ballast
- stabilizer
- water
- urethane resin
- resin solution
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01B—PERMANENT WAY; PERMANENT-WAY TOOLS; MACHINES FOR MAKING RAILWAYS OF ALL KINDS
- E01B27/00—Placing, renewing, working, cleaning, or taking-up the ballast, with or without concurrent work on the track; Devices therefor; Packing sleepers
-
- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01B—PERMANENT WAY; PERMANENT-WAY TOOLS; MACHINES FOR MAKING RAILWAYS OF ALL KINDS
- E01B1/00—Ballastway; Other means for supporting the sleepers or the track; Drainage of the ballastway
- E01B1/001—Track with ballast
-
- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01B—PERMANENT WAY; PERMANENT-WAY TOOLS; MACHINES FOR MAKING RAILWAYS OF ALL KINDS
- E01B2204/00—Characteristics of the track and its foundations
- E01B2204/03—Injecting, mixing or spraying additives into or onto ballast or underground
Landscapes
- Engineering & Computer Science (AREA)
- Architecture (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Materials Applied To Surfaces To Minimize Adherence Of Mist Or Water (AREA)
- Paints Or Removers (AREA)
Abstract
Disclosed herein is a ballast stabilizer to be sprayed on the surface of ballast (railroad bed) which is composed mainly of a urethane resin solution based on the water-blowing formulation. The stabilizer readily disperses and infiltrates into ballast and distributes itself uniformly throughout the upper and lower layers of ballast.
Description
'93 12/28 16:02 ~052 203 4027 IIDA PAT.BUREAU 1~004 - 2i 1~612 BALLAST STABILIZER
BACKGROUND OF THE INVENTION
1. ~ield of the Invention:
The present invention relates to a- ballast stabilizer to be sprayed on the surface of ballast (rallroad bed).
Z. Description of the Prior Art:
The railroad track is generally composed of rails and their accessories, ties, and ballast. The ballast serves to distribute vehicle loads and absorb shocks which rails and ties receive from wheels. It consists of gravel or crashed stone laid between ties and subgrade and around ties. Ballast is subject to total or partial subsidence and lateral displacement in a short period of time under the influence of vibrations and loads, because it has a myriad of interstices between its pieces. In addition, it is often blown off by wind pressure produced by running vehicles. A common practice to cope with this situation has been to spray a stabilizer (such as curable epoxy resin) on the surface of ballast so as to bond ballast pieces together. In other words, the ballast is stabilized by the aid of a curable polymer for filling and bonding. The stabilizer is usually a liquid of low viscosity so that it evenly disperses and infiltrates into the layered ballast.
Unfortunately, the stabilizer does not distribute itself '93 12/28 16:03 ~PoS2 203 4027 IIDA PAT.BUREAU b~oO5 21 1261~
uniformly in ballast because it easily penetrates into the lower layer but hardly remains in the upper layer. In other words, with conventional practice it is difficult to have the upper layer to hold enough stab$1izer for filling interstices and bonding ballast pieces. To cope with this situation, it is necessary to repeat the spraying and curing of the stabilizer several times.
Meanwhile, attempts have been made to incorporate the stab$1izer with inorganic fillers such as talc, calcium car~onate, and asbestos to e~h~nce its effect (especially filling effect). Such additives, however, increase the viscosity of the stabilizer and hence prevents the stabilizer from uniformly dispersing and infiltrating into ballast, w~th the result that more stabilizer exists in the upper layer than in the lower layer of ballast.
SUMMARY OF THE INVENTION
It is an ob~ect o~ the present invention to provide a ballast stabilizer which uniformly disperses and infiltrates into both the upper and lower layers of ballast to increase its strength.
The present invention is embodied in a ballast stabilizer to be sprayed on the surface of ballast, said stabilizer comprising, as the principal constituent, a urethane resin solution based on the water-blowing formulation.
' 93 12/28 16: 03 1~052 203 4027 I IDA PAT. BUREAU 1~ 006 - 21 12~1~
The ballast stabilizer of the present invention uniformly disperses and infiltrates into both the upper and lower layers of ballast. The formulation is characterized by that a urethane resin is dissolved in a hydrophilic solvent to which water is added dlrectly or indirectly. The stabilizer of this formulation effectively fills lnterstlces in ballast, strengthening the layers of ballast, as shown in Examples given later. The probable reason for this is that the urethane resin dissolved in a hydrophilic solvent does not form emulsion (as a cause for increased viscosity) in the initial stage of reactlon, unlike that dissolved in a hydrophobic solvent. The result is a uniform dispersion of the resin solution into ballast.
In the last stage of reaction, the resin solution becomes emulsified due to solvent evaporation and remains in the interstices of ballast without flowing downward. In addition, the urethane resin solution incorporated with water readily forms a cured polymer containing fine bubbles uniformly in a short time. This polymer also contributes to increasing the strength.
According to the present invention, the urethane resin solution may be incorporated with coal tars or a similar water-repellent o~l, which lmparts the thixotropic properties to the stabilizer to enhance its performance, particularly in the case of wet ballast.
' 93 12/28 16: 04 1~052 203 4027 I IDA PAT. BUREAU 1~ 007 21 1261~
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention will be described in more detail in the following lin which Uparts" and ~%u are based on weight, unless otherwise stated).
The ballast stabilizer of the present invention is used to stabilize railroad ballast by spraying on its surface. It comprises, as the principal constituent, a urethane resin solution based on the water-blowing formulation. The urethane resin solution may be of either one pack type or two-pack type so long as it infiltrates into ballast and foams and cures therein at an adequate rate. In the case of one-pack type, the urethane resin should preferably be diluted with a hydrophilic solvent to which water as the blowing agent is added directly or indirectly.
The urethane resin for one-pack formulation (before curing) is in the form of prepolymer with terminal isocyanate groups. (The prepolymer may be based on polyester, polyether, or polyester-polyether.) An example of the prepolymer is "Sumidule E-21" commercially available from Sumitomo Bayer Urethane Co., Ltd.
The hydrophilic organic solvent is not specifically restricted so long as it is miscible with water. It may be a water-soluble organic solvent with or without a water-insoluble organic solvent. The water-soluble solvent is ' 93 12/28 16: 04 ~052 203 4027 I IDA PAT. BUREAU 1~ 008 one which freely dissolves in water. It includes lower alcohols (such as methanol, ethanol, and isopropyl alcohol), polyhydric alcohols and monoethers thereof (such as ethylene glycol and cellosolve), and ketones (such as acetone and methyl ethyl ketone). The water-insoluble solvent is one which is insoluble or very lightly soluble in water. It includes hydrocarbons (such as xylene, toluene, and benzene3 and esters (such as ethyl acetate and isopropyl acetate).
The concentration of the urethane resin solution usually ranges from 10% to 80%, depending on how fast and deep the stabilizer infiltrates into ballast.
The amount of water to be added should be about 0.2-5~
of the amount of the diluent (hydrophilic solvent). An excessively small amount of water causes insufficient foaming and hence incomplete flllLng. An excessively large amount of water causes premature curing (before infiltration into ballast) and hence incomplete filling.
It is desirable to add water to the stabilizer directly beforehand. However, it is also possible to add water to the stabilizer indirectly by wetting ballast before spraying. Under the circumstances of high humidity, it is not necessary to add water, because interstices in ballast usually contain much water (moisture) due to condensation.
' 93 12/28 16: 05 ~052 203 4027 I IDA PAT. BUREAU 1~ 009 -- 21~ a6 l~
The ballast stabilizer should preferably be incorporated with coal tars or a similar water-repellent oil (both collectively referred to as coal tars hereina~ter).
Coal tars imparts the thixotropic properties to the stabilizer. It contrlbutes to the filling of interstices of ballast and increases the strength of baliast. In addition, it also adequately controls the rate of foaming and curing of the urethane resin in wet ballast. Due to its water-repellency, it replaces waterdrops in ballast with the stabilizer and prevents abrupt reactions with water. The result is moderate foaming and the cured stabilizer has an adequate density necessary for the ~esired strength. The amount of coal tars is not specifically restricted; however, it should preferably be not greater than about 15% of resin solids,because as the amount of coal tars increases, the urethane resin becomes slow in cure rate and poor in adhesion to ballast. (Slow curing leads to a low productivity.) Coal tars should preferably be used in combination with a cure accelerator (such as ester amine) to accelerate curing. In addition, coal tars may be used in combination with or may be replaced by any chemical agent which imparts the thixotropic properties to the stabilizer and increases the strength of ballast.
The stabilizer may be incorporated with, in addition to '93 12/28 16:06 S~052 203 4027 IIDA PAT.BUREAU 1~010 ` 211~612 the above-mentioned components, an inorganic filler (such as calcium carbonate, talc, and silicates), surface active agent, and age resistor in an amount not harm~ul to the effect of the present invention.
The stabilizer prepared as mentioned above is sprayed on ballast in the usual way. The amount of spraying is 0.5-6 kg/m2 for 25 cm thick ballast. Spraying with an excess amount results in the excess foaming which separates ballast pieces and weakens ballast.
EXAMPLES
To evaluate the effect of the invention, tests were conducted as follows:
A sample of the stabilizer was prepared from "Sumidule E-21" (non-solvent type, one-pack urethane resin from Sumitomo Bayer Urethane Co., Ltd.) by dilution in a water-xoluble organic solvent containing or not containing water.
The concentration of the solution is expressed in terms of % of contents (urethane resin). Incidentally, the water-soluble solvent was dehydrated before use to eliminate the effect of water.
A sample of ballast was prepared from particles retained on a 50 mm sieve and passing a 70 mm sieve. The ballast was ~ried before use. The ballast was put in a cylindrical polyethylene container (296 mm in inside diameter and 368 mm deep), with its bottom having 5 holes '93 12/28 16:06 ~052 203 4027 IIDA PAT.BUREAU l~011 211~612 (each 10 mm in diameter).
The stabilizer was sprayed on the ballast put in the container, using an airless sprayer and a nozzle placed 18 cm away from the surface of the ballast. The spray pressure was 764 kPa (8 kgf/cm~). After spraying, the ballast was allowed to stand for 24 hours to cure the urethane resin.
The resulting ballast is referred to as cured ballast.
The cured ballast was tested for the following items.
Voids: calculated from the formula below.
(W, -- W2 ) C
where W, : weight of ballast before water filling, W2 weight of ballast after water filling, C : volume of the cylindrical container.
Filling of voids: calculated from the formula below.
(V~ - V2 ) . V, x 100 where Vl : voids before spraying, V2 : voids after spraying, Compression strength: measured using an Amsler testing machine.
Example 1 Samples of the stabilizer were prepared according to the formulations shown in Table 1. Each sample (600 g) was sprayed on the ballast prepared as mentioned above. The cured ballast was examined for voids. The experiments are intended to investigate the effect of water added to the '93 12/28 16:07 ~052 203 4027 IIDA PAT.BUREAII l~012 `~ 2112S12 solvent on the filling of voids in the ~allast. The results o~ the experiments are shown in Table 2. It is noted that the resin solution of the same concentration varies in the effect of filling voids in the ballast depending on whether it is incorporated with water.
(Compare Run Nos. 4, 5, 6, 4A, and 6A with ~un Nos. 4W, SW, 6W, 4AW, and 6AW, respectively.) Table 1 Run No. Resin Diluent Water in content (%) diluent (%) 1 30 Xylene 0 2 30 Toluene 0 3 30 Ethyl acetate 0 4 30 Acetone 0 - 5 30 M.E.K. 0 6 30 Methanol 0 lA 60 Xylene 0 2A 60 Toluene 0 3A 60 Ethyl acetate 0 4A 60 Acetone 0 5A 60 M.E.K. 0 6A 60 Methanol 0 4W 30 Acetone 0.42 5w 30 M.~.K. 0.42 6W 30 Methanol 0.42 4AW 60 Acetone 0.80 6AW 60 Methanol 0.80 '93 12/28 16:07 ~052 203 4027 IIDA PAT.BUREAU l~bO13 ~112~12 .
Table 2 Run No.Voids before Voids after Filled voids curing (%) curing (%) (%) 1 49.87 49.~4 1.67 2 50.2~ ~9.4~ 1.57 3 49.91 49.15 l.S2 4 51.03 50.30 1.43 49.76 49.0~ 1.43 6 50.85 50.07 1.53 lA 50.42 48.77 3 27 2A 49.73 48.10 3 28 3A 50.08 48.49 3.17 4A 51.13 49.53 3.13 5A 49.76 48.16 3.22 6A 50.11 48.48 3.25 9W 50.34 47.69 5.26 ~W 51.18 48.48 5.28 6W 49.69 47.06 5.30 4AW 49.?5 93.18 l3.21 6AW 51.50 44.49 13.61 Example 2 Samples of the stabilizer were prepared according to the formulations shown in Table 3. Each sample (1000 ~) was sprayed on the ballast. The cured ballast was tested for compression strength. The experiments are intended to investigate the effect of water added to the solvent on the compression strength of the cured ballast. The results of the experiments are shown in Table 4. It is noted that the resin solution of the same concentration varies in the effect of strengthening the ballast depending on whether it is incorporated with water. (Compare Run Nos. 3 and 4 with Run Nos. 3W and 4W, respectively.) The same effect as mentioned above is obtained i f the water-soluble solvent '93 12/28 16:08 2P052 203 4027 IIDA PAT.BUREAU l~bOl4 .
- - 211~612 (such as acetone and methanol) is mixed with a water-insoluble solvent (such as toluene and xylene) and the resulting mixed solvent is incorporated with water. (Refer to Run Nos. 13W, 23W, and 123W.) Ta~le 3 Run No. Resin Diluents and mix- WateE in content (%) ing ratio (%)diluent (%) 1 50 Xylene (100) 0 2 S0 Toluene (100) 0 3 50 Acetone (100) 0 4 50 Methanol (100) 0 3W 50 Acetone (99) 1.0 4W 50 Methanol (99) 1.0 13W 50 Xylene (49.5) 1.0 Acetone ~49.5) 23W 50 Toluene (49.5) 1.0 Acetone (49.5) 123W 50 Xylene (33) 1.0 Toluene (33) Acetone (33) Table 4 Run No. Voids before Voids after Compression curing (%) curing (%)strength (g/cm2) 1 49.78 48.80 113.3-~
2 50.32 48;97 121.82 3 Sl.41 49.99 119.69 4 49.92 48.46 126.14 3W 49.86 41.78 521.45 4W 49.91 42.33 573.20 13W 50.73 42.16 50~
23W 50.68 41.92 510.77 123W q9.49 41.04 S23.68 Example 3 Samples of the stabilizer were prepared according to the formulations shown in Table 5. Each sample (1000 g) was sprayed on the ballast (p~t in the container) which had been immersed in tap for 24 hours and allowed to stand for '93 12/28 16:09 ~052 203 4027 IIDA PAT.BUREAU 6~015 1 hour. The average water content in the ballast was 13.58%. The cured ballast was tested for compression sLrengt~. The cxpcr~mcr~to arQ ~ntc~ndc~d to i~aetigatA thA
effect of water in the ballast and the effect of water-soluble diluent on the compression strength of the cured ballast. The results of the experiments are shown in Table 6. It is noted that the effect of strengthening the wet ballast is produced in the case of hydrophilic solvent (including mixed solvents containing a hydrophilic solvent).
This effect, however, is inferior to the effect in the case where the solvent is incorporated with water. (Compare Run Nos. 4 to 10 with Run Nos. 3W to 23W in Example 2.) It is also noted that no effect of strength ening the wet ballast was obtained in the case where the solvent is not hydrophilic. (See Run Nos. 1 to 3.) Table S
Run No. Resin Diluents and mixing Water in content (%) ratio (%) diluent (~) 1 60 Xylene (100) 0 2 60 Toluene (100) 0 3 60 Ethyl acetate (100) 0 4 60 Acetone (100) 0 M.~.K. (100) 0 6 60 Methanol (100) 0 7 60 Xylene ~50) 0 Acetone (50) 8 60 Toluene t50) 0 Acetone (50) g 60 ~thyl acetate (50) 0 Acetone (50) Ethyl acetate (50) 0 Methanol (50) '93 12/28 16:09 ~052 203 4027 IIDA PAT.BUREAU 1~016 - 21 ~2612 Table 6 Run Voids Voids Filled Compression No. before after voids (%) strengt~
curing (%) curing (%) ~g/cm2) 1 50.37 45.94 8.79 34 57 2 49.94 45.59 8.71 33.01 3 51.43 47.05 8.52 39.46 4 50.16 43.9512.38 332.48 50.23 44.6211.17 145.66 6 49.90 43.8512.12 365.19 7 49.77 44.1011.39 237.39 8 51.01 45.6010.61 234 22 9 49.56 43.9511.32 278.67 50.38 44.5~11.51 309.06 Example 4 Samples of the stabilizer were prepared according to the formulations shown in Table 7. Each sample (lO00 g) was sprayed on the wet ballast prepared in Example 3. The cured ballast was tested for compression strength. The coal tars in the formulation is "Tarcrone 180L" made by Yoshida Seiyusho Co., Ltd. The measurement of compression strength was carried out after the sample had been cured (by standing) for 48 hours at room temperature because the stabilizer containing coal tars takes a longer time to cure.
The experiments are intended to investigate the effect of coal tars added to the stabilizer on the compression strength of the cured ballast. ~Coal tars delays the '93 12/28 16:10 ~052 203 4027 IIDA PAT.BUREAU 1~017 211 ~612 reaction cf water with the urethane resin.) The results of the experiments are shown in Table 8. It is noted that the stabilizer incorporated with coal tars greatly increases the strength of the wet ballast. (Compare Run Nos. 1 to 10 with Run Nos. 1 to 10 in Example 3, respectively.) - Table 7 Run Resin Tar Diluents and mixing Water in No. solids content ratio (%) diluent (%) (~ 3 1 60 5 Xylene (100) 0 2 60 5 Toluene (100) 0 3 60 5 Ethyl acetate (100) 0 4 60 5 Acetone (100) 0 5 M.E.K. (100) 0 6 60 5 Methanol (100) 0 7 60 5 Xylene (50) 0 Acetone (50) 8 60 5 Toluene (50) 0 Acetone (50) 9 60 5 Ethyl acetate (50) 0 Acetone (50) 6n 5 E~thyl ~c~t~t~ ~50) 0 Methanol (50) Table 8 Run Voids Voids Eilled Compresslon No.before after voids (%) strength curing (%) curing (~) (g/cm2) 1 50.28 46.98 5.5658.32 2 S2.03 48.66 5.4862.08 3 51.14 47.68 5.7777.62 4 49.88 45.97 7.83468.60 49.43 46.08 6.77321.37 6 50.46 46.08 8.68492.68 7 49.65 46.07 7.2137~.89 8 50.51 46.95 7.05398.53 9 49.17 45.53 7.40442.06 49.41 45.58 7.96416.80 Example 5 Samples of the stabilizer were prepared according to the ~ormulations shown in Table 9. Each sample (1000 g) was sprayed on dry ballast. The cured ballast was tested for l 4 '93 12/28 16:10 ~052 203 4027 IIDA PAT.BUREAU l~018 - - 21126 l~
compression strength. The coal tars in the formulation is "Tarcrone 180L" made by Yoshida Seiyusho Co., Ltd. The stabilizer was incorporated with a cure accelerator of ester amine tipe (in an amount of 3% of resin solids) because coal tars decelerates the cure rate of the urethane resin. The measurement of compression strength was carried out after the sample had been cured (by standing) for 48 hours. The experiments are intended to investigate the effect of coal tars and water added to the stabilizer on the compression strength of the cured ballast. The results of the experiments are shown in Table lO. It is noted that the stabilizer incorporated with coal tars, water, and cure accelerator greatly increases the strength of the dry ballast. (Refer to Run Nos. l to 6.) Table 9 Run Resin Tar Diluents and mixing Water in No. c~ntent content ratio (%) diluent ( ) ) ( ) 1 60 10 Acetone (98) 2 2 60 10 Methanol (98) 2 3 60 10 Xylene (49) 2 Acetone (49) 4 60 10 Toluene (49) 2 Acetone (49) Ethyl acetate (49) 2 Acetone (49) 6 60 10 Ethyl acetate (49) 2 Methanol (49) Table 10 Run Voids Voids Filled Compression No. be~ore after voids (%) strength curing (%) curing (%) ~g/cm2) 1 49.68 42.16 15.141063.01 2 52.73 44.63 15 371255 27 3 50.43 42.51 15 71907 36 4 49.94 42.28 15.34941.44 51.55 43.72 15.18975.99 6 50.78 42.9g 15.34994.10 l 5 '93 12/28 16:11 ~052 203 4027 ~IDA PAT.BUREAU 1~019 2~ 126 ~ ~
Example 6 The same procedure as in Example 5 was repeated except that the amount of the stabilizer sprayed was changed to 3.5 kg to see the effect o~ the increased amount of the stabilizer on the strength of the ballast. The results are shown in Table 11. It ~s noted that the strength of the ballast increases with the increasing amount of the stabilizer.
Table 11 ~un Voids Voids Filled Compression No. before after voids (%) strength curing (~) curing (%) tkg~cm2) 1 50.g6 21.67 58.66 8.~5 2 51.81 19.59 62.19 9.22 3 49.04 21.86 5S.42 8.23 4 49.44 22.04 55.45 8.60 S 50.39 21.30 57.73 8.67 6 49.60 20.91 57.85 8.71
BACKGROUND OF THE INVENTION
1. ~ield of the Invention:
The present invention relates to a- ballast stabilizer to be sprayed on the surface of ballast (rallroad bed).
Z. Description of the Prior Art:
The railroad track is generally composed of rails and their accessories, ties, and ballast. The ballast serves to distribute vehicle loads and absorb shocks which rails and ties receive from wheels. It consists of gravel or crashed stone laid between ties and subgrade and around ties. Ballast is subject to total or partial subsidence and lateral displacement in a short period of time under the influence of vibrations and loads, because it has a myriad of interstices between its pieces. In addition, it is often blown off by wind pressure produced by running vehicles. A common practice to cope with this situation has been to spray a stabilizer (such as curable epoxy resin) on the surface of ballast so as to bond ballast pieces together. In other words, the ballast is stabilized by the aid of a curable polymer for filling and bonding. The stabilizer is usually a liquid of low viscosity so that it evenly disperses and infiltrates into the layered ballast.
Unfortunately, the stabilizer does not distribute itself '93 12/28 16:03 ~PoS2 203 4027 IIDA PAT.BUREAU b~oO5 21 1261~
uniformly in ballast because it easily penetrates into the lower layer but hardly remains in the upper layer. In other words, with conventional practice it is difficult to have the upper layer to hold enough stab$1izer for filling interstices and bonding ballast pieces. To cope with this situation, it is necessary to repeat the spraying and curing of the stabilizer several times.
Meanwhile, attempts have been made to incorporate the stab$1izer with inorganic fillers such as talc, calcium car~onate, and asbestos to e~h~nce its effect (especially filling effect). Such additives, however, increase the viscosity of the stabilizer and hence prevents the stabilizer from uniformly dispersing and infiltrating into ballast, w~th the result that more stabilizer exists in the upper layer than in the lower layer of ballast.
SUMMARY OF THE INVENTION
It is an ob~ect o~ the present invention to provide a ballast stabilizer which uniformly disperses and infiltrates into both the upper and lower layers of ballast to increase its strength.
The present invention is embodied in a ballast stabilizer to be sprayed on the surface of ballast, said stabilizer comprising, as the principal constituent, a urethane resin solution based on the water-blowing formulation.
' 93 12/28 16: 03 1~052 203 4027 I IDA PAT. BUREAU 1~ 006 - 21 12~1~
The ballast stabilizer of the present invention uniformly disperses and infiltrates into both the upper and lower layers of ballast. The formulation is characterized by that a urethane resin is dissolved in a hydrophilic solvent to which water is added dlrectly or indirectly. The stabilizer of this formulation effectively fills lnterstlces in ballast, strengthening the layers of ballast, as shown in Examples given later. The probable reason for this is that the urethane resin dissolved in a hydrophilic solvent does not form emulsion (as a cause for increased viscosity) in the initial stage of reactlon, unlike that dissolved in a hydrophobic solvent. The result is a uniform dispersion of the resin solution into ballast.
In the last stage of reaction, the resin solution becomes emulsified due to solvent evaporation and remains in the interstices of ballast without flowing downward. In addition, the urethane resin solution incorporated with water readily forms a cured polymer containing fine bubbles uniformly in a short time. This polymer also contributes to increasing the strength.
According to the present invention, the urethane resin solution may be incorporated with coal tars or a similar water-repellent o~l, which lmparts the thixotropic properties to the stabilizer to enhance its performance, particularly in the case of wet ballast.
' 93 12/28 16: 04 1~052 203 4027 I IDA PAT. BUREAU 1~ 007 21 1261~
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention will be described in more detail in the following lin which Uparts" and ~%u are based on weight, unless otherwise stated).
The ballast stabilizer of the present invention is used to stabilize railroad ballast by spraying on its surface. It comprises, as the principal constituent, a urethane resin solution based on the water-blowing formulation. The urethane resin solution may be of either one pack type or two-pack type so long as it infiltrates into ballast and foams and cures therein at an adequate rate. In the case of one-pack type, the urethane resin should preferably be diluted with a hydrophilic solvent to which water as the blowing agent is added directly or indirectly.
The urethane resin for one-pack formulation (before curing) is in the form of prepolymer with terminal isocyanate groups. (The prepolymer may be based on polyester, polyether, or polyester-polyether.) An example of the prepolymer is "Sumidule E-21" commercially available from Sumitomo Bayer Urethane Co., Ltd.
The hydrophilic organic solvent is not specifically restricted so long as it is miscible with water. It may be a water-soluble organic solvent with or without a water-insoluble organic solvent. The water-soluble solvent is ' 93 12/28 16: 04 ~052 203 4027 I IDA PAT. BUREAU 1~ 008 one which freely dissolves in water. It includes lower alcohols (such as methanol, ethanol, and isopropyl alcohol), polyhydric alcohols and monoethers thereof (such as ethylene glycol and cellosolve), and ketones (such as acetone and methyl ethyl ketone). The water-insoluble solvent is one which is insoluble or very lightly soluble in water. It includes hydrocarbons (such as xylene, toluene, and benzene3 and esters (such as ethyl acetate and isopropyl acetate).
The concentration of the urethane resin solution usually ranges from 10% to 80%, depending on how fast and deep the stabilizer infiltrates into ballast.
The amount of water to be added should be about 0.2-5~
of the amount of the diluent (hydrophilic solvent). An excessively small amount of water causes insufficient foaming and hence incomplete flllLng. An excessively large amount of water causes premature curing (before infiltration into ballast) and hence incomplete filling.
It is desirable to add water to the stabilizer directly beforehand. However, it is also possible to add water to the stabilizer indirectly by wetting ballast before spraying. Under the circumstances of high humidity, it is not necessary to add water, because interstices in ballast usually contain much water (moisture) due to condensation.
' 93 12/28 16: 05 ~052 203 4027 I IDA PAT. BUREAU 1~ 009 -- 21~ a6 l~
The ballast stabilizer should preferably be incorporated with coal tars or a similar water-repellent oil (both collectively referred to as coal tars hereina~ter).
Coal tars imparts the thixotropic properties to the stabilizer. It contrlbutes to the filling of interstices of ballast and increases the strength of baliast. In addition, it also adequately controls the rate of foaming and curing of the urethane resin in wet ballast. Due to its water-repellency, it replaces waterdrops in ballast with the stabilizer and prevents abrupt reactions with water. The result is moderate foaming and the cured stabilizer has an adequate density necessary for the ~esired strength. The amount of coal tars is not specifically restricted; however, it should preferably be not greater than about 15% of resin solids,because as the amount of coal tars increases, the urethane resin becomes slow in cure rate and poor in adhesion to ballast. (Slow curing leads to a low productivity.) Coal tars should preferably be used in combination with a cure accelerator (such as ester amine) to accelerate curing. In addition, coal tars may be used in combination with or may be replaced by any chemical agent which imparts the thixotropic properties to the stabilizer and increases the strength of ballast.
The stabilizer may be incorporated with, in addition to '93 12/28 16:06 S~052 203 4027 IIDA PAT.BUREAU 1~010 ` 211~612 the above-mentioned components, an inorganic filler (such as calcium carbonate, talc, and silicates), surface active agent, and age resistor in an amount not harm~ul to the effect of the present invention.
The stabilizer prepared as mentioned above is sprayed on ballast in the usual way. The amount of spraying is 0.5-6 kg/m2 for 25 cm thick ballast. Spraying with an excess amount results in the excess foaming which separates ballast pieces and weakens ballast.
EXAMPLES
To evaluate the effect of the invention, tests were conducted as follows:
A sample of the stabilizer was prepared from "Sumidule E-21" (non-solvent type, one-pack urethane resin from Sumitomo Bayer Urethane Co., Ltd.) by dilution in a water-xoluble organic solvent containing or not containing water.
The concentration of the solution is expressed in terms of % of contents (urethane resin). Incidentally, the water-soluble solvent was dehydrated before use to eliminate the effect of water.
A sample of ballast was prepared from particles retained on a 50 mm sieve and passing a 70 mm sieve. The ballast was ~ried before use. The ballast was put in a cylindrical polyethylene container (296 mm in inside diameter and 368 mm deep), with its bottom having 5 holes '93 12/28 16:06 ~052 203 4027 IIDA PAT.BUREAU l~011 211~612 (each 10 mm in diameter).
The stabilizer was sprayed on the ballast put in the container, using an airless sprayer and a nozzle placed 18 cm away from the surface of the ballast. The spray pressure was 764 kPa (8 kgf/cm~). After spraying, the ballast was allowed to stand for 24 hours to cure the urethane resin.
The resulting ballast is referred to as cured ballast.
The cured ballast was tested for the following items.
Voids: calculated from the formula below.
(W, -- W2 ) C
where W, : weight of ballast before water filling, W2 weight of ballast after water filling, C : volume of the cylindrical container.
Filling of voids: calculated from the formula below.
(V~ - V2 ) . V, x 100 where Vl : voids before spraying, V2 : voids after spraying, Compression strength: measured using an Amsler testing machine.
Example 1 Samples of the stabilizer were prepared according to the formulations shown in Table 1. Each sample (600 g) was sprayed on the ballast prepared as mentioned above. The cured ballast was examined for voids. The experiments are intended to investigate the effect of water added to the '93 12/28 16:07 ~052 203 4027 IIDA PAT.BUREAII l~012 `~ 2112S12 solvent on the filling of voids in the ~allast. The results o~ the experiments are shown in Table 2. It is noted that the resin solution of the same concentration varies in the effect of filling voids in the ballast depending on whether it is incorporated with water.
(Compare Run Nos. 4, 5, 6, 4A, and 6A with ~un Nos. 4W, SW, 6W, 4AW, and 6AW, respectively.) Table 1 Run No. Resin Diluent Water in content (%) diluent (%) 1 30 Xylene 0 2 30 Toluene 0 3 30 Ethyl acetate 0 4 30 Acetone 0 - 5 30 M.E.K. 0 6 30 Methanol 0 lA 60 Xylene 0 2A 60 Toluene 0 3A 60 Ethyl acetate 0 4A 60 Acetone 0 5A 60 M.E.K. 0 6A 60 Methanol 0 4W 30 Acetone 0.42 5w 30 M.~.K. 0.42 6W 30 Methanol 0.42 4AW 60 Acetone 0.80 6AW 60 Methanol 0.80 '93 12/28 16:07 ~052 203 4027 IIDA PAT.BUREAU l~bO13 ~112~12 .
Table 2 Run No.Voids before Voids after Filled voids curing (%) curing (%) (%) 1 49.87 49.~4 1.67 2 50.2~ ~9.4~ 1.57 3 49.91 49.15 l.S2 4 51.03 50.30 1.43 49.76 49.0~ 1.43 6 50.85 50.07 1.53 lA 50.42 48.77 3 27 2A 49.73 48.10 3 28 3A 50.08 48.49 3.17 4A 51.13 49.53 3.13 5A 49.76 48.16 3.22 6A 50.11 48.48 3.25 9W 50.34 47.69 5.26 ~W 51.18 48.48 5.28 6W 49.69 47.06 5.30 4AW 49.?5 93.18 l3.21 6AW 51.50 44.49 13.61 Example 2 Samples of the stabilizer were prepared according to the formulations shown in Table 3. Each sample (1000 ~) was sprayed on the ballast. The cured ballast was tested for compression strength. The experiments are intended to investigate the effect of water added to the solvent on the compression strength of the cured ballast. The results of the experiments are shown in Table 4. It is noted that the resin solution of the same concentration varies in the effect of strengthening the ballast depending on whether it is incorporated with water. (Compare Run Nos. 3 and 4 with Run Nos. 3W and 4W, respectively.) The same effect as mentioned above is obtained i f the water-soluble solvent '93 12/28 16:08 2P052 203 4027 IIDA PAT.BUREAU l~bOl4 .
- - 211~612 (such as acetone and methanol) is mixed with a water-insoluble solvent (such as toluene and xylene) and the resulting mixed solvent is incorporated with water. (Refer to Run Nos. 13W, 23W, and 123W.) Ta~le 3 Run No. Resin Diluents and mix- WateE in content (%) ing ratio (%)diluent (%) 1 50 Xylene (100) 0 2 S0 Toluene (100) 0 3 50 Acetone (100) 0 4 50 Methanol (100) 0 3W 50 Acetone (99) 1.0 4W 50 Methanol (99) 1.0 13W 50 Xylene (49.5) 1.0 Acetone ~49.5) 23W 50 Toluene (49.5) 1.0 Acetone (49.5) 123W 50 Xylene (33) 1.0 Toluene (33) Acetone (33) Table 4 Run No. Voids before Voids after Compression curing (%) curing (%)strength (g/cm2) 1 49.78 48.80 113.3-~
2 50.32 48;97 121.82 3 Sl.41 49.99 119.69 4 49.92 48.46 126.14 3W 49.86 41.78 521.45 4W 49.91 42.33 573.20 13W 50.73 42.16 50~
23W 50.68 41.92 510.77 123W q9.49 41.04 S23.68 Example 3 Samples of the stabilizer were prepared according to the formulations shown in Table 5. Each sample (1000 g) was sprayed on the ballast (p~t in the container) which had been immersed in tap for 24 hours and allowed to stand for '93 12/28 16:09 ~052 203 4027 IIDA PAT.BUREAU 6~015 1 hour. The average water content in the ballast was 13.58%. The cured ballast was tested for compression sLrengt~. The cxpcr~mcr~to arQ ~ntc~ndc~d to i~aetigatA thA
effect of water in the ballast and the effect of water-soluble diluent on the compression strength of the cured ballast. The results of the experiments are shown in Table 6. It is noted that the effect of strengthening the wet ballast is produced in the case of hydrophilic solvent (including mixed solvents containing a hydrophilic solvent).
This effect, however, is inferior to the effect in the case where the solvent is incorporated with water. (Compare Run Nos. 4 to 10 with Run Nos. 3W to 23W in Example 2.) It is also noted that no effect of strength ening the wet ballast was obtained in the case where the solvent is not hydrophilic. (See Run Nos. 1 to 3.) Table S
Run No. Resin Diluents and mixing Water in content (%) ratio (%) diluent (~) 1 60 Xylene (100) 0 2 60 Toluene (100) 0 3 60 Ethyl acetate (100) 0 4 60 Acetone (100) 0 M.~.K. (100) 0 6 60 Methanol (100) 0 7 60 Xylene ~50) 0 Acetone (50) 8 60 Toluene t50) 0 Acetone (50) g 60 ~thyl acetate (50) 0 Acetone (50) Ethyl acetate (50) 0 Methanol (50) '93 12/28 16:09 ~052 203 4027 IIDA PAT.BUREAU 1~016 - 21 ~2612 Table 6 Run Voids Voids Filled Compression No. before after voids (%) strengt~
curing (%) curing (%) ~g/cm2) 1 50.37 45.94 8.79 34 57 2 49.94 45.59 8.71 33.01 3 51.43 47.05 8.52 39.46 4 50.16 43.9512.38 332.48 50.23 44.6211.17 145.66 6 49.90 43.8512.12 365.19 7 49.77 44.1011.39 237.39 8 51.01 45.6010.61 234 22 9 49.56 43.9511.32 278.67 50.38 44.5~11.51 309.06 Example 4 Samples of the stabilizer were prepared according to the formulations shown in Table 7. Each sample (lO00 g) was sprayed on the wet ballast prepared in Example 3. The cured ballast was tested for compression strength. The coal tars in the formulation is "Tarcrone 180L" made by Yoshida Seiyusho Co., Ltd. The measurement of compression strength was carried out after the sample had been cured (by standing) for 48 hours at room temperature because the stabilizer containing coal tars takes a longer time to cure.
The experiments are intended to investigate the effect of coal tars added to the stabilizer on the compression strength of the cured ballast. ~Coal tars delays the '93 12/28 16:10 ~052 203 4027 IIDA PAT.BUREAU 1~017 211 ~612 reaction cf water with the urethane resin.) The results of the experiments are shown in Table 8. It is noted that the stabilizer incorporated with coal tars greatly increases the strength of the wet ballast. (Compare Run Nos. 1 to 10 with Run Nos. 1 to 10 in Example 3, respectively.) - Table 7 Run Resin Tar Diluents and mixing Water in No. solids content ratio (%) diluent (%) (~ 3 1 60 5 Xylene (100) 0 2 60 5 Toluene (100) 0 3 60 5 Ethyl acetate (100) 0 4 60 5 Acetone (100) 0 5 M.E.K. (100) 0 6 60 5 Methanol (100) 0 7 60 5 Xylene (50) 0 Acetone (50) 8 60 5 Toluene (50) 0 Acetone (50) 9 60 5 Ethyl acetate (50) 0 Acetone (50) 6n 5 E~thyl ~c~t~t~ ~50) 0 Methanol (50) Table 8 Run Voids Voids Eilled Compresslon No.before after voids (%) strength curing (%) curing (~) (g/cm2) 1 50.28 46.98 5.5658.32 2 S2.03 48.66 5.4862.08 3 51.14 47.68 5.7777.62 4 49.88 45.97 7.83468.60 49.43 46.08 6.77321.37 6 50.46 46.08 8.68492.68 7 49.65 46.07 7.2137~.89 8 50.51 46.95 7.05398.53 9 49.17 45.53 7.40442.06 49.41 45.58 7.96416.80 Example 5 Samples of the stabilizer were prepared according to the ~ormulations shown in Table 9. Each sample (1000 g) was sprayed on dry ballast. The cured ballast was tested for l 4 '93 12/28 16:10 ~052 203 4027 IIDA PAT.BUREAU l~018 - - 21126 l~
compression strength. The coal tars in the formulation is "Tarcrone 180L" made by Yoshida Seiyusho Co., Ltd. The stabilizer was incorporated with a cure accelerator of ester amine tipe (in an amount of 3% of resin solids) because coal tars decelerates the cure rate of the urethane resin. The measurement of compression strength was carried out after the sample had been cured (by standing) for 48 hours. The experiments are intended to investigate the effect of coal tars and water added to the stabilizer on the compression strength of the cured ballast. The results of the experiments are shown in Table lO. It is noted that the stabilizer incorporated with coal tars, water, and cure accelerator greatly increases the strength of the dry ballast. (Refer to Run Nos. l to 6.) Table 9 Run Resin Tar Diluents and mixing Water in No. c~ntent content ratio (%) diluent ( ) ) ( ) 1 60 10 Acetone (98) 2 2 60 10 Methanol (98) 2 3 60 10 Xylene (49) 2 Acetone (49) 4 60 10 Toluene (49) 2 Acetone (49) Ethyl acetate (49) 2 Acetone (49) 6 60 10 Ethyl acetate (49) 2 Methanol (49) Table 10 Run Voids Voids Filled Compression No. be~ore after voids (%) strength curing (%) curing (%) ~g/cm2) 1 49.68 42.16 15.141063.01 2 52.73 44.63 15 371255 27 3 50.43 42.51 15 71907 36 4 49.94 42.28 15.34941.44 51.55 43.72 15.18975.99 6 50.78 42.9g 15.34994.10 l 5 '93 12/28 16:11 ~052 203 4027 ~IDA PAT.BUREAU 1~019 2~ 126 ~ ~
Example 6 The same procedure as in Example 5 was repeated except that the amount of the stabilizer sprayed was changed to 3.5 kg to see the effect o~ the increased amount of the stabilizer on the strength of the ballast. The results are shown in Table 11. It ~s noted that the strength of the ballast increases with the increasing amount of the stabilizer.
Table 11 ~un Voids Voids Filled Compression No. before after voids (%) strength curing (~) curing (%) tkg~cm2) 1 50.g6 21.67 58.66 8.~5 2 51.81 19.59 62.19 9.22 3 49.04 21.86 5S.42 8.23 4 49.44 22.04 55.45 8.60 S 50.39 21.30 57.73 8.67 6 49.60 20.91 57.85 8.71
Claims (14)
1. A ballast stabilizer to be sprayed on the surface of ballast, said stabilizer comprising, as the principal constituent, a urethane resin solution based on the water-blowing formulation.
2. A ballast stabilizer as defined in Claim 1, wherein the urethane resin solution is that of two-pack urethane resin.
3. A ballast stabilizer as defined in Claim 1, wherein the urethane resin solution is that of one-pack urethane resin which is diluted with a hydrophilic organic solvent and incorporated directly or indirectly with water as a blowing agent.
4. A ballast stabilizer as defined in Claim 3, wherein the hydrophilic organic solvent consists solely of a water-soluble organic solvent.
5. A ballast stabilizer as defined in Claim 3, wherein the hydrophilic organic solvent is a mixture of a water-soluble organic solvent and a water-insoluble organic solvent.
6. A ballast stabilizer as defined in Claim 3, wherein the urethan resin solution contains about 10 to 80 wt% resin.
7. A ballast stabilizer as defined in Claim 3, wherein the urethane resin solution contains water in an amount of about 0.2-5 wt% of the hydrophilic organic solvent.
8. A ballast stabilizer as defined in Claim 3, wherein the urethane resin solution is incorporated with coal tars or a similar water-repellent oil (both collectively referred to as coal tar hereinafter).
9. A ballast stabilizer as defined in Claim 8, wherein the coal tars is added in an amount not greater than about 15 wt% of resin solids.
10. A ballast stabilizer as defined in Claim 8, wherein the coal tars is used in combination with a cure accelerator.
11. A method of stabilizing ballast which comprises spaying on ballast a ballast stabilizer composed mainly of a urethane resin solution based on the water-blowing formulation.
12. A method of stabilizing ballast as defined in Claim 11, wherein the urethane resin solution is that of two-pack urethane resin.
13. A method of stabilizing ballast as defined in Claim 12, wherein the urethane resin solution contains water in an amount of about 0.2-5 wt% of the hydrophilic organic solvent.
14. A method of stabilizing ballast as defined in Claim 12, wherein the urethane resin solution is incorporated with coal tars.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2112612 CA2112612A1 (en) | 1993-12-30 | 1993-12-30 | Ballast stabilizer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2112612 CA2112612A1 (en) | 1993-12-30 | 1993-12-30 | Ballast stabilizer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2112612A1 true CA2112612A1 (en) | 1995-07-01 |
Family
ID=4152686
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2112612 Abandoned CA2112612A1 (en) | 1993-12-30 | 1993-12-30 | Ballast stabilizer |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2112612A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011110489A1 (en) * | 2010-03-09 | 2011-09-15 | Bayer Materialscience Ag | Polyurethane elastomer ballast mat and preparation thereof |
-
1993
- 1993-12-30 CA CA 2112612 patent/CA2112612A1/en not_active Abandoned
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011110489A1 (en) * | 2010-03-09 | 2011-09-15 | Bayer Materialscience Ag | Polyurethane elastomer ballast mat and preparation thereof |
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