IJR International Journal of Railway

Vol. 9, No. 2 / December 2016, pp. 27-35

Vol. 9, No. 2 / December 2016 − 27 −

The Korean Society for Railway

Developing Track Ballast Characteristic Guideline

In Order To Evaluate Its Performance

J. M. Sadeghi, J. Ali Zakeri and M. Emad Motieyan Najar†

Abstract

In spite of recent advances in ballasted railway track, the correct choice of ballast for rail track is still considered critical

because aggregates progressively deteriorate under traffic loading and environmental exposures. Various ballast require-

ments, functions and duties have been defined by researchers, railway companies and countries’ regulations even though

it needs to be integrated to make following proper decision during track operation and maintenance. A proper under-

standing of ballast properties and suitable tests are prerequisites for minimizing maintenance costs.

This paper presents a capable classification for ballast characteristics which need to be investigated beforehand to such a

way, firstly to assign ballast functions, secondly need to clarify ballast requirements, thirdly to map appropriate tests to

evaluate ballast characteristics and then it must be such that if ballast cannot carry out one of these duties, be able to call

there is ballast defect. The paper is structured in order to achieve these objectives.

Keywords: Track Ballast, Railway track maintenance, Ballast specification, Quality Assessing

1. Introduction

Rail tracks are conventionally built on compacted granu-

lar platforms called as ballast, which are laid on natural

formation. Ballast layer is main structural part of railroad

where the sleepers are laid on. Ballast layer is the largest

component of the track more than 1600 m3 and 2500 met-

ric tons by volume and weight respectively for single track

in one kilometer. A common problem with this part of

track is the premature degradation of ballast due to

increasing traffic passage, loads and speed, so that leading

to fail of high track quality, cause to maintenance works

and consequently huge upkeep and downtime cost.

Prior to 1970 generally there were no significant consid-

eration on relationship between ballast type and its proper-

ties, maintenance performance and costs. The thing which

was important purchases price and hauling cost (DIPI-

LATO, Steinberg et al. 1983). Sources of ballast often cho-

sen by the railway just based on the vicinity to be

inexpensive and satisfied minimum specifications set forth

by the client.

Therefore, choosing proximity cheaper material quite

resulted poor performance and that required frequent

maintenance to keep track operation safe and with good

quality for running.

Previously some available data on performance of road

and highway coarse material and concrete aggregates

might be appropriate for use in ballast studies(Robnett,

Thompson et al. 1975, Brattli 1992). But, the performance

of a railway track is highly affected by the ballast charac-

teristics and properties in response to train loading (Hay

1982, Selig, Yoo et al. 1982, Li and Selig 1995).

Over time in terms of applied stress levels and aggre-

gate environmental exposure it was necessary to define

required and quantifiable characteristics of ballast that

respond to the all aspects of ballast environmental factors

and traffic loading. Since 1970 two approaches small scale

laboratory and in service full scale have been used to study

track ballast. Engineers and researchers primarily have

concentrated on such area: 1- Mechanical properties of

ballast; 2- Evaluation of ballast performance in operating

track; 3- Ballast behavior in track under traffic and cyclic

† Corresponding author: Iran University of Science and Technology-School of Rail-

way Engineering. Narmak, Iran.

E-mail : m.motieyan@gmail.com

ⓒThe Korean Society for Railway 2016

https://doi.org/10.7782/IJR.2016.9.2.027

− 28 −

J. M. Sadeghi, J. Ali Zakeri and M. Emad Motieyan Najar / IJR, 9(2), 27-35, 2016

loads.

Some conducted investigation (Thompson 1977, Alva-

hurtado and Selig 1979, Simon, Edgers et al. 1983, John-

son 1985) in America, (Dalton 1973, Raymond, Gaskin et

al. 1975, Raymond 1978, Raymond and Williams 1978) in

Canada, (Parkin and Adikari 1981) have been published.

In Europe and under International Union of railway (UIC)

some studies have been executed from 1970 to 1975.

Because of long life span of railway, for ballast studies

in real track it was required to spend plenty time to find

out ballast behavior and responses during its services

period. They had to create accelerated tests to realize bal-

last actions in short time to enable predicting long behav-

ior of ballast in tracks(Raymond, Gaskin et al. 1975,

Raymond, Gaskin et al. 1975, Raymond and Davies 1978,

Siller 1980, Alva-Hurtado and Selig 1981, Debra and

Ernest 1990, Indraratna, Ionescu et al. 1997, Ionescu, Indr-

aratna et al. 1998, Key 1998, Indraratna and Ionescu 1999,

Indraratna, Lackenby et al. 2005, Aursudkij 2007, Bach

and Veit 2013) Other Following, researchers and practic-

ing engineers based on knowledge of experiences and

experiments, established ballast functions and codify bal-

last layer characteristics and requirements to carry out its

duties as a well component of track.

At present, various types of tests and experiments have

introduced to evaluate the ballast characteristics, however,

the railway authorities worldwide do not agree on which

the optimum ballast index characteristics are.

Demand increasing cause to heavier traffic load and run-

ning speed to the track, which will inevitably give a more

rapid degradation of the ballast material and an increase in

loss of track geometry(Bathurst and Raymond 1987). This

can to some extent be avoided by clarification and opti-

mizing the ballast specifications regarding reduced defects

in track due ballast layer, maintenance cost and increasing

track quality and services. Nowadays, in view point of

economy, the life cycle costs of ballast are not governed

by purchase or transport cost, but by the cost of mainte-

nance work such as tamping and ballast cleaning to keep

service quality. By shifting the focus of the maintenance

strategy from meeting safety limits to obtaining cost-effec-

tive maintenance via ballast features recognizing so much

better, high quality track standards can be achieved and

maintained.

2. Ballast

2.1 Ballast functions

Different ballast duties have been reported and inter-

preted by researchers and railway engineers so far in the

world (Robnett, Thompson et al. 1975, Hay 1982, Selig

and Waters 1994, Esveld 2001, Indraratna, Khabbaz et al.

2003, Indraratna, Khabbaz et al. 2006). The fundamental

and major functions of ballast can be summarized as fol-

lows:

1. To distribute load by from the sleeper uniformly to

acceptable stress level over the subgrade assisting in

track stability and disperse intensity of load over

underneath layers.

2. Supports track structure, anchors the track in place

against lateral, vertical and longitudinal movement.

3. Provide a resilient support layer to reduce transmis-

sion of dynamic loads to under layers and assists in

absorbing shock and airborne noise.

4. Provide rapid and easily drainage any moisture intro-

duced into the track.

5. Provide a ready means for adjusting track geometry to

reestablish line and grade.

6. Provide an insulating layer to limit frost penetration

into the subgrade.

7. provide a cover to deter growth of plants in the track

2.1.1 Ballast portions

Ballast layer can be divided in to four zones in con-

structed and operating track: 1. Crib: ballast zones

between the sleepers; 2. Shoulder: the sloppy zone

between the end of the sleeper and down to the top of sub-

ballast; 3. Top ballast: the top portion of the ballast struc-

ture which is usually exposed to tamping; 4. Bottom bal-

last: the bottom and lower part of the structure which

support the overall structure; depend on the quality of the

sub-ballast material, loading condition, presence of water

and drainage property of the structure; it is the more

fouled part of the structure than the rest of the structure.

Only the top and bottom ballast distributes the load trans-

mitted from a sleeper down to the sub-ballast and further

on to the subgrade. The role of crib ballast and shoulder

ballast is mainly to provide minimum confinement against

lateral and longitudinal movement for track stability.

The contribution of each part in playing the roles of bal-

last function to perform duties is presented in table (1).

Fig. 1 Schematic of ballast zones in railway track

Developing Track Ballast Characteristic Guideline In Order To Evaluate Its Performance

− 29 −

2.1.2 Ballast specifications

Generally, ballast material should be sufficiently tough

to resist breakage under impact, hard to resist abrasion due

to inter particle contact, dense enough to resist lateral

forces and finally holding the sleepers in place. It must be

also freeze-thaw resistant which results further degrada-

tion due to weathering and chemical effect. The ballast

materials should be non-void particles, when the voids

filled with water, during winter it will get freeze, which

will form inter particle volume change finally causes bulg-

ing of layers. In addition, it should be free of dust and dirt

and resistant to cementing action (Knutson 1977, Chris-

mer 1986, Chanda and Krishna 2003, Indraratna, Khab-

baz et al. 2003, Kerr 2003, Ionescu 2005).

To perform its duties, ballast layer should meet some

requirements. For appraising of requirements, need to clas-

sify the specification of granular ballast material to pre-

pare an adequate guideline to assess its characteristics.

Requirements for supply of ballast aggregate for railway

track construction can be relied on mechanical, environ-

mental, physical and profile properties after laying track

down. A proposed ballast characteristic categorization is

depicted in figure (2) as below.

The physical behavior of ballast material can be esti-

mated by evaluating the shape, surface texture and its

angularity or roundness. The mechanical behavior of bal-

last in railway track can be controlled by strength and

resistance to attrition, abrasion and breakdown under traf-

fic loading. Ballast layer profile is governing track stabil-

ity and resistance to vertical, longitudinal and lateral

applied load by running train and thermal forces which is

happened by temperature variation.

Also the ballast properties should be assessed during it

lifespan exposed to the climate changing, chemical alter-

ation, wet-dry cycle, freeze-thaw cycles, and weathering

impact. For measuring these specifications, various crite-

ria and experiments are proposed by railway authorities.

Ballast layer profile

The thickness of the ballast should be such that the sub-

grade is loaded as uniformly possible. The thickness is

usually measured from the lower side of the sleeper

(Esveld 2001).

Ballast confining pressure depends on the thickness of

ballast layer especially in crib part(Indraratna, Nimbalkar

et al. 2009). Ballast settlement occurs in a railway sub-

jected to long-term traffic loading depends on ballast

thickness. Ballast shoulder width and side slope need to

provide confining pressure and lateral strength to the

track. Also longitudinal and lateral deviation of ballast

layer from designed layer should be considered as irregu-

larity of ballast layer geometry.

Physical properties

Grading of aggregate is the most commonly requested

test within this media. The purpose of the test is to deter-

mine the varying amounts of material contained in stan-

dard size segment.

Drainage and compaction facilities are one of the impor-

tance properties for ballast media to have been carried.

Therefore gradation and sieve analysis is one of the main

criterion for ballast particle size evaluation.(Sharpe 2000)

The next ballast physical characteristic is grain specific

gravity, in addition to sustainability and ballast layer stabil-

ity may be gross indicator for mineral composition. The

voids within an aggregate particle should not be confused

with the void system which makes up the space between

particles in an aggregate mass. Pore size is related to the

average particle size and gradation, degree of consolida-

tion or in-place bulk density. Therefore bulk density of

ballast aggregate is a function of two factors; 1- particle

density and media void content. So the results should be

expressed in terms of void ratio (porosity) in addition to

bulk density to eliminate the variety of particle density

(Selig and Waters 1994). Later part is related to shape of

Table 1 Contribution of ballast portions to perform ballast duties

Ballast DutiesCrib

Ballast

Shoulder

Ballast

Bottom

Ballast

Top

Ballast

Vertical strength ■ ■

Lateral strength ■ ■ ■

Longitudinal strength ■ ■

Resiliency ■ ■

Adjusting and track leveling ■ ■ ■

Drainage ■ ■ ■ ■

Load distribution and

dispersing ■ ■

Prevent growth of plant ■ ■ ■

Shock absorption and noise

attenuation■ ■ ■ ■

Electrical resistivity ■ ■

Subgrade protection layer ■ ■ ■ ■

Fig. 2 Classification of ballast specification regarding its

properties in railway track

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J. M. Sadeghi, J. Ali Zakeri and M. Emad Motieyan Najar / IJR, 9(2), 27-35, 2016

particles called “particle shape index” included; angular-

ity, flakiness and elongation indices. The particle shape of

an aggregate is the percentage of the mass determined as

flaky or elongated.

Environmental properties

Wet-Dry Resistance can be a primarily test to assess

environmental properties of ballast. Such clay stone, mud

stone and shale will disintegrate if subjected to dry-wet-

ting alteration cycle. They contaminate ballast layer by fri-

able particles and clay lump which are susceptible to break

down under wet-dry action. The next water absorption test

is used to determine saturated porosity. This observation

can predict freeze – thaw cycle resistance. It is recom-

mended air drying instead of oven prior to immersing in

water. Water absorption testing is performed in conjunc-

tion with determining the particle density, both in the dry

state and in the Saturated Surface Dry condition (SSD).

Soaking duration effects to absorbed water con-

tent(Nålsund 2014).

Freeze-thaw action can affect ballast performance in two

ways: 1- The pressure caused by freeze-thaw within the

aggregate water- filled voids tends to fragmentation and

split, 2-Freeze-thaw cycle changes elastic and inelastic bal-

last layer mechanical behavior under load due to thaw

softening and frost heave.

Sulfate soundness test is proposed as an index to predict

freeze-thaw cycle resistance of ballast aggregates. The test

is thought to operate by forming salt crystal within aggre-

gate pores which cause internal pressure similar to freeze-

thaw experience by icing expansion.

Another most important test is chemical activity poten-

tial. The rate of environmental alteration of ballast aggre-

gate depends on many factors, including coarse

mineralogy, temperature, available moisture, particle sur-

face, particle size, season’s weather condition, and chemi-

cal contaminants.

Mechanical properties

Mechanical tests are considered as the best and most

important indicators of ballast performance in service.

Raymond and Meeker examined ballast materials pro-

vided from various quarries in North America, and arrived

at the conclusion that, in general, fine grained, hard-min-

eral and unweathered aggregates are best as ballast materi-

als (Raymond 1979, Meeker 1990). The important and

primer effective factor is parent rock source. Although

there is general classification for rock properties in view

point of geo-technique, in figure (3), a proposed classifica-

tion is introduced for selection of rock for ballast produc-

ing and using in railway track. As shown in figure (3),

from left toward right the coarser-grained igneous rocks

such as granite, diorite and gabbro, along with the hard-

mineral grained form the best source, then Hypabyssal

rock type, followed by the extrusive igneous rocks (rhyo-

lite, andesite and basalt) the most adequate and then meta-

morphic rocks such as quartzite, gneiss, and finally well-

cemented sedimentary (Lime stone and dolomite,..) and

Fig. 3 Proposed parent rock classification for selection of ballast aggregate

Developing Track Ballast Characteristic Guideline In Order To Evaluate Its Performance

− 31 −

slag as weakest aggregate can be chosen. The experiments

results for sedimentary, metamorphic and igneous rocks

shows, the first two rock types are weaker in abrasion than

the later (Ozcelik 2011).

In ballast petrographic test, by identifying inherent phys-

ical properties of the parent rocks and minerals in ballast

aggregate and estimating percentage composition, it is

capable to map rock source based on the classification and

mineralogy, evaluate chemical activities, and provide the

clues of the susceptibility to weathering, soundness, hard-

ness and toughness properties(Johansson, Lukschová et al.

2011).

However, the evaluation is mostly subjective and value

of the analysis and prediction obviously depend on the

skill and experience of the petrographer. Some relation-

ships between petrographic results and identifiable rock

particle properties by petrographic analysis have been

studied (Watters, Klassen et al. 1987, Nålsund 2014).

Hardness index is using for measuring the abrasion

resistance of aggregate interaction under the loading by

friction grain are being scratch by another grain.

Toughness describes individual aggregate resistance to

impact and is ability to absorb the compelled energy in

track. It can be the fracture surface energy required to cre-

ate unit new crack surface.(Aursudkij 2007).

3. Ballast Examining

To identify ballast testing methods which provide results

reflecting the field performance of different ballast materi-

als, various tests are recommended and performed by

researchers. In the case of achieving appropriate ballast

recognition regarding its characteristics needs to perform

these general and well-known tests as categorized in table

Table 2. Track ballast layer specification indices

Ballast properties Characteristics Test method Terms of evaluation

Mechanical

Hardness &Toughness Los Angeles Abrasion, attrition and fragmentation

Hardness Deval attrition test (dry, wet) Surface abrasion test

Hardness Micro Deval Surface abrasion test

Toughness Aggregate Crushing Value Fragmentation and crushing resistance

Hardness Scratch (Mohs)Hardness Surface abrasion to produce fines

Toughness Point load Strength Fragmentation(splitting)

Toughness Aggregate impact Value Aggregate resistance to sudden shock, fracturing

Hardness Dorry abrasion Surface abrasion to produce fines

Hardness Mill abrasion Surface abrasion to produce fines

Clue to Hardness, toughness and

soundness

Petrography analysis

(intact particles/Fines)Mineralogy , Chemical alteration

Physical

Gradation Particle size distribution Compaction energy and drainage ability

Gradation Fineness of material Drainage

Stability Particle density Stability and indirect toughness

Stability Bulk density Inter particle void, drainage and track stability

Shape index Particle shape Fragmentation(splitting) and drainage

Environmental

Soundness Dry-wet Durability and weathering resistance

Soundness Freeze and Thaw Durability and weathering resistance

Soundness Water absorption Saturation and weathering resistance

Soundness Aggregate Porosity Durability and weathering resistance

Soundness Magnesium/Sodium sulfate Durability and weathering resistance

Soundness Friable particles , clay lumps Durability and preliminary abrasion

Geometrical Cross Profile

Thickness Track structural stability, resiliency and damping

Shoulder width Track lateral stability

Side slope Track structural stability

Layer Deviation Unevenness, misalignment Track stability to ride comfortable

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J. M. Sadeghi, J. Ali Zakeri and M. Emad Motieyan Najar / IJR, 9(2), 27-35, 2016

(2) to measure needful indices in terms of evaluation of

ballast specifications.

These tests are concerned with establishing a quantita-

tive estimate of the resistance to in track instability and

degradation under loading.

Beside mentioned tests, some supplementary test are

being used to simulate actual ballast field performance in

order to assess the reliability compared to using simple

laboratory tests. Odeometer, ballast box test, triaxial test

and full scale railway track model test are supplementary

tests to find out more realistic behavior of ballast under

cyclic loading; however are costly and time consum-

ing(Selig and Waters 1994, Indraratna, Khabbaz et al.

2003, Indraratna, Khabbaz et al. 2004, Indraratna, Khab-

baz et al. 2006, Aursudkij 2007).

Recommended control parameters and selection criteria

for ballast assessment can be divided in three stages of

ballast source and particle, assembly particle and ballast

constructed layer which are presented in figure (4) and (5).

In the case of ballast requirements a set of standards and

tests have been identified. Railway authorities throughout

the world follows their own local or common standards to

ensure uniform material compliance and appropriate bal-

last aggregate for use in track. In table (3) based on recom-

mended classification for ballast characteristics evaluation

through selected technical codes of America, Europe and

Australia a compilation of corresponding items is briefly

presented.

4. Conclusion

Recently, more attention is given for both the superstruc-

ture and substructure part of the track to get good perfor-

mance for heavier wheel loads, higher operating speeds

and unit trains. Based on the evaluation of track ballast

through required experiments, physical, mechanical, envi-

ronmental and geometry of ballast profile properties

according to adopting thresholds, it is possible to insure

better overall performance of the track structure which

requires minimum cost of maintenance. However, fre-

quently, availability and cost have been the prime factors

considered in the selection of ballast materials, but all over

performance and required life span of the railway should

be safe and cost effectiveness. Hence the cheapest ballast

means that, track structure not having low cost all over its

service period.

The characteristics of ballast layer can be divided into

four categories, mechanical, environmental, physical and

geometry that quantify its performance. These specifica-

tion data are obtained by conducting series laboratory,

field tests and also evaluating the performance of the dif-

ferent ballast materials under existing condition on the

track

It is therefore very important for railway to have full

information about ballast service period identifying meth-

ods of construction and they should already be laid down

in its specification. This article presents a comprehensive

study of ballast functions and its properties. It proposes

mechanism to reach appropriate tests to improve the avail-

ability of the track for ballast services.

References

1. Alva-hurtado, J. and E. Selig (1979). “Static and DynamicProperties of Railroad Ballast.”

2. Alva-Hurtado, J. and E. Selig (1981). Permanent strainbehavior of railroad ballast. Proceedings of The Interna-

Fig. 4 Assessment steps in track ballast evolution

Fig. 5 Ballast characteristic controlling tests in term of ballast

evolution

Developing Track Ballast Characteristic Guideline In Order To Evaluate Its Performance

− 33 −

Table 3 Compiled track ballast assessment based on proposed categorization of ballast technical requirement

Test zone RequirementsAustralia

(AS 2758.7) (2009)

Europe EN13450

(2003)

USA

AREMA(2012)

Physical

Particle size distribution (PSD) AS 1141.11.1 EN933-1 ASTM-C136

% material passing No. 200

sieve %

Max 1 %

AS 2758.7

Max 0.5-1.5 %

(0.063mm)

EN 933-1

Max 1%

ASTM-C117

Clay lumps and friable particles

%-- --

Max 0.5 %

ASTM-C142

Particle Density

(Specific gravity)

Min 2.5 t/m3

(dry)

EN1097-2

CEN ISO/TS

17892-3

Min 2.6 t/m3

ASTM-C127

Bulk Density

(unit weight)

Min 1.2 t/m3

(AS1141.4)

NSW Min 1.4 t/m3

CEN ISO/TS

17892-2

Min 1.12 t/m3

C29

Misshapen

particles

Elongation2:1 ratio Max 30%

3:1 possible Alt.

3:1, Max 4-12%

EN 933-3

Length>100mm

<6%

Max 5 %

ASTM D4791

3:1

FlakinessMax 30 %

AS1141.14

Max 15-35 %

EN 933-3 (1997)

Max 5 %

ASTM D4791

Crushed Surface

(texture)

Min 75 % by mass

2 crushed faces-- --

Environmental

Soundness and resistance to the

weathering

Water absorption% -- EN1097-6Max 1 - 2%

ASTM-C127

Freeze and Thaw Cycle --EN-NS 1367-1

(20 cycles)--

Sulfate test --EN 1367-2

(1% NaCl-10 cycle)

Max 5 %

ASTM-C88

(5 cycles)

Clay lumps and friable particles

%-- --

Max 0.5 %

ASTM-C142

Mechanical

Wet attrition Test

Micro-Deval --Max 5 – 15%

EN 1097-1--

Mill Attrition Test -- ----AN= LAA+5MA*

25%<AN<65%

Wet Attrition Value (WAV)Max 6%,8%,12 % based on class of track

1141.27--- ----

Toughness

Fragmentation

And fracturing

resistance

Los Angles Value

(LA)

Max 25 %, 30%, 40% based on class of track

(1141.23)

Max 12 to 24 %

EN 1097-2

Max 30%

ASTM-C535- C131

Aggregate Crushing Value

(ACV)

Max 25%, 30%, 40% based on class of track

(AS 1141.21)--- --

Impact Value (IV) ---14%<IV<22%

EN1097-2

Strength

Wet : Min 175 KN , 150 KN , 110 KN

Wet/dry variation: max 25%, 30%,40%

Based on track class

AS 1141.22

--

Point load test

Dry>1200 kg

Wet>800

DrainageCEN ISO/TS

17892-11--

Electric Conductivity Min 60 Ohm.m

1289.4.4.1-- --

Ballast profile

(Geometry of layer)

Ballast Depth

underside of sleeper to the top of the

finished formation

325, 275, 225 mm based on class of track -->12 in**

Main line

Ballast shoulder width

400-700 mm

(CWR, LWR***)

300-700 mm

Loose rail

-->12 in (CWR)

Main line

Side Slope of the ballast shoulderHeight: horizontal

1:1.5--

Height: horizontal

1:2

Crib zone To the top level of sleeper -- --

*Abrasion Number is an index included Los Angeles and mill abrasion loss.

**The measurement is made under the line rail in tangent track, or under inside rail in curved track, and is made with respect to the top of

the sub-ballast at the center line.

***CWR: continued welded rail, LWR: long welded rail

− 34 −

J. M. Sadeghi, J. Ali Zakeri and M. Emad Motieyan Najar / IJR, 9(2), 27-35, 2016

tional Conference on Soil Mechanics and Foundation Engi-neering, 10th.

3. Aursudkij, B. (2007). A laboratory study of railway ballastbehaviour under traffic loading and tamping maintenance,University of Nottingham.

4. Bach, H. and P. Veit (2013). Evaluation of attrition tests forrailway ballast.

5. Bathurst, R. J. and G. P. Raymond (1987). Geogrid reinforce-ment of ballasted track.

6. Brattli, B. (1992). “The influence of geological factors onthe mechanical properties of basic igneous rocks used asroad surface aggregates.” Engineering Geology 33(1): 31-44.

7. Chanda, M. and R. Krishna (2003). “Selection and testing ofballast stones for underground railway tracks.” African Jour-nal of science and technology 4(2): 42-50.

8. Chrismer, S. (1986). “Considerations of factors affecting bal-last performance.” American Railway Engineering Associa-tion 87.

9. Dalton, C. (1973). “Field Durability Tests on Ballast Sam-ples as a Guide to the Significance of the SpecificationRequirements.” Canadian National Railways TechnicalResearch Centre, St. Laurent, Quebec, Canada: 40.

10. Debra, L. B. and T. S. Ernest (1990). “Abrasion tests for rail-road ballast.”

11. DIPILATO, M., E. Steinberg and R. SIMON (1983). BallastAnd Subgrade Requirements Study: Railroad Track Sub-structure--Design and Performance Practices, Federal Rail-road Administration.

12. Esveld, C. (2001). “Modern railway track.”13. Hay, W. W. (1982). Railroad engineering, John Wiley &

Sons.14. Indraratna, B. and D. Ionescu (1999). Deformation of bal-

last under static and dynamic loading. Pre-failure Deforma-tion Characteristics of Geomaterials: Proceedings of theSecond International Symposium on Pre-Failure Deforma-tion Characteristics of Geomaterials: Torino 99: Torino, Italy28-30 September, 1999, CRC Press.

15. Indraratna, B., D. Ionescu, D. Christie and R. Chowdhury(1997). “Compression and degradation of railway ballastunder one-dimensional loading.” Faculty of Engineering-Papers: 403.

16. Indraratna, B., H. Khabbaz and J. Lackenby (2003).Behaviour of railway ballast under dynamic loads based onlarge-scale triaxial testing. AusRAIL PLUS 2003, 17-19November 2003, Sydney, NSW, Australia.

17. Indraratna, B., H. Khabbaz and W. Salim (2004). “Ballast-formation-track interaction mechanism based on large scalelaboratory testing.” CORE 2004: New Horizons for Rail: 30.

18. Indraratna, B., H. Khabbaz, W. Salim and D. Christie (2006).“Geotechnical properties of ballast and the role of geosyn-thetics.”

19. Indraratna, B., J. Lackenby and D. Christie (2005). “Effectof confining pressure on the degradation of ballast undercyclic loading.”

20. Indraratna, B., S. Nimbalkar and D. Christie (2009). “The

performance of rail track incorporating the effects of ballastbreakage, confining pressure and geosynthetic reinforce-ment.”

21. Ionescu, D. (2005). “Ballast degradation and measurementof ballast fouling.” Railway technical review(2).

22. Ionescu, D., B. Indraratna and H. D. Christie (1998). Defor-mation of railway ballast under dynamic loads. Conferenceon Railway Engineering Proceedings: Engineering Innova-tion for a Competitive Edge, Central Queensland University.

23. Johansson, E., Š. Lukschová and K. Miškovský (2011).“Petrographic characteristics of granitoid and gabbroid intru-sive rocks as a tool for evaluation of mechanical properties.”E. Johansen (2011): Technological properties of rock aggre-gates. PhD Thesis, Luleå University of Technology, Luleå,Sweden.

24. Johnson, D. (1985). Investigation of practical ballast specifi-cation requirements, Association of American Railroads.

25. Kerr, A. D. (2003). Fundamentals of railway track engineer-ing.

26. Key, A. J. (1998). Behaviour of two layer railway track bal-last under cyclic and monotonic loading, University of Shef-field.

27. Knutson, M. (1977). Materials Foundation Study—Ballastand Foundation Materials Research Program, Tech. RepFRA-OR&D-77-02, Federal Railroad Administration, Wash-ington, DC, USA.

28. Li, D. and E. T. Selig (1995). “Wheel/track dynamic interac-tion: track substructure perspective.” Vehicle SystemDynamics 24(sup1): 183-196.

29. Meeker, L. E. (1990). Engineering and economic factorsaffecting the cost of railroad ballast.

30. Nålsund, R. (2014). “Railway ballast characteristics, selec-tion criterion and performance.”

31. Ozcelik, Y. (2011). “Predicting Los Angeles abrasion ofrocks from some physical and mechanical properties.” Sci-entific Research and Essays 6(7): 1612-1619.

32. Parkin, A. and G. Adikari (1981). Rockfill deformation fromlarge scale tests. Proceedings of the 10th International Con-ference Soil Mechanical and Foundations EngineeringStockholm.

33. Raymond, G., P. Gaskin, J. Davies, K. Van Dalen and O.Svec (1975). Laboratory Performance of Railroad Ballast.Second Australia-New Zealand Conference on Geomechan-ics, Institution of Engineers, Australia.

34. Raymond, G. P. (1978). “Design for railroad ballast and sub-grade support.” Journal of the Geotechnical EngineeringDivision 104(1): 45-60.

35. Raymond, G. P. (1979). “Railroad ballast prescription: state-of-the-art.” Journal of Geotechnical and GeoenvironmentalEngineering 105(2).

36. Raymond, G. P. and J. R. Davies (1978). “Triaxial tests ondolomite railroad ballast.” Journal of Geotechnical and Geo-environmental Engineering 104(ASCE 13835).

37. Raymond, G. P., P. N. Gaskin and O. Svec (1975). Selectionand performance of railroad ballast.

Developing Track Ballast Characteristic Guideline In Order To Evaluate Its Performance

− 35 −

38. Raymond, G. P. and D. R. Williams (1978). “Repeated loadtriaxial tests on a dolomite ballast.” Journal of Geotechnicaland Geoenvironmental Engineering 104(7).

39. Robnett, Q., M. Thompson, W. Hay, S. Tayabji and R. Knut-son (1975). Technical data bases report. Ballast and Founda-tion Materials Research Program.

40. Selig, E., T. Yoo and C. Panuccio (1982). MECHANICS OFBALLAST COMPACTION. VOLUME I: TECHNICALREVIEW OF BALLAST COMPACTION AND RELATEDTOPICS.

41. Selig, E. T. and J. M. Waters (1994). Track geotechnologyand substructure management, Thomas Telford.

42. Sharpe, P. (2000). Trackbed investigation. Journal and reportof proceedings-Permanent Way Institution, Permanent WayInstitution.

43. Siller, T. (1980). “Properties of railroad ballast and subbal-last for track performance prediction.” Master's projectreport. Con-crete Tie Correlation Study, Department of CivilEngineering, University of Massachusetts, Amherst.

44. Simon, R., L. Edgers and J. Errico (1983). Ballast and Sub-grade Requirements Study: Railroad Track Substructure-Materials Evaluation and Stabilization Practices.

45. Thompson, M. (1977). “FAST Ballast and Subgrade Materi-als Evaluation.” Ballast and Foundation Materials ResearchProgram, University of Illinois at Urbana-Champaign. forUS Federal Railroad Administration, Report No. FRA/ORD-77/32.

46. Watters, B., M. Klassen and A. Clifton (1987). Evaluation ofballast materials using petrographic criteria.