Arema Cap. 30 (Part 5) - Composite Ties

© 2008, American Railway Engineering and Maintenance-of-Way Association 30-5-1

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30, Par

Part 5

Engineered Composite Ties

— 2006 —

FOREWORD

This specification is intended to provide necessary guidance in the design, manufacture, and use of engineered

composite ties and their components for main line standard gage railway ballasted track systems. Engineered

composite ties include both polymer composites and engineered wood products. The specification contains

minimum performance requirements for components of engineered composite tie railway track. Track

constructed of tie and fastener components meeting the specifications applicable to the anticipated usage

should be expected to give satisfactory performance under current AAR-approved maximum axle loads.

The specification covers materials, physical dimensions, physical properties, and structural strength of

engineered composite ties. The specification does not cover techniques or equipment for the manufacture of

engineered composite ties or special fastenings.

Engineered composite ties are a relatively new technology compared to the more conventional sawn wood,

concrete, or steel ties. Passages of this specification, especially those pertaining to polymer composites ties,

include commentary considered beneficial to help the engineer responsible for track design to better

understand the sometimes unique properties of these materials. This specification will be revised as

appropriate using data generated by ongoing laboratory and field testing and in-service experience.

Where current specifications or recommended practices of other technical societies, such as ASTM

International are appropriate, they are made part of this specification by reference.

TABLE OF CONTENTS

Section/Article Description Page

5.1 General Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-5-2

5.1.1 Introduction (2006) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-5-2

5.2 Material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-5-3

5.2.1 General (2003) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-5-3

5.2.2 Composite Tie Types (2003) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-5-3

5.3 Physical and Mechanical Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-5-4

5.3.1 General (2006) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-5-4

5.3.2 Dimensional Requirements (2006) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-5-5

5.3.3 Performance Requirements (2006). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-5-5

Ties

© 2008, American Railway Engineering and Maintenance-of-Way Association

30-5-2 AREMA Manual for Railway Engineering

TABLE OF CONTENTS (CONT)

Section/Article Description Page

5.4 Special Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-5-8

5.4.1 General (2003) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-5-8

5.4.2 For Engineered Polymer Composite (EPC) Ties (2006) . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-5-8

5.4.3 For Engineered Wood Product (EWP) Ties (2006) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-5-10

5.5 Quality Control, Inspection, and Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-5-11

5.5.1 Production Quality Control (2006) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-5-11

5.5.2 Tie Identification and Records (2006) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-5-12

5.5.3 Certification (2006). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-5-12

LIST OF FIGURES

Figure Description Page

30-5-1 Engineered Wood Product Orientations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-5-10

LIST OF TABLES

Table Description Page

30-5-1 Physical and Mechanical Properties. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30-5-7

SECTION 5.1 GENERAL CONSIDERATIONS

5.1.1 INTRODUCTION (2006)

a. In supporting and guiding railway vehicles, the track structure must restrain repeated lateral, vertical,

and longitudinal forces in order to maintain surface, line, and gage. As elements of the track structure,

individual ties receive loads from the rails or fastenings, and in turn they transmit loads to the ballast

and subgrade. Consequently, the design of a tie affects and is affected by characteristics of other

components of the track structure. Engineered composite ties combine two or more materials (e.g.,

selected reinforcing elements and/or fillers) in a matrix binder to obtain properties superior to the

individual components. The two general types of engineered composite ties covered by Part 5 are:

(1) Engineered polymer composite (EPC) – a material system that incorporates reinforcements (e.g.,

glass fibers) and/or other property modifiers in a polymer matrix.

(2) Engineered wood product (EWP) – wood laminates or strands bonded together with a structural

adhesive (e.g., phenolic).

b. While the use of engineered composite ties may require some different considerations in design and

installation, the products can be used both in new construction and as maintenance ties for a standard

wood tie track structure.

c. Engineered composite ties are designed to utilize the same tie spacing and ballast structure as wood ties.

The ties can be installed using conventional cut spikes or screw spikes with standard installation



AREMA Manual for Railway Engineering 30-5-3

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equipment. Specific installation details, such as which spikes work best, size of predrilled holes, etc.,

should be based on the tie manufacturer’s recommendations.

d. For increased lateral and longitudinal track stability, polymer composite ties can be manufactured with

specially designed surface patterns to create a mechanical interlock between the tie and the ballast.

Individual manufacturers have different proprietary designs to provide a range of lateral track stability.

Use of surface-modified ties is particularly recommended with welded-rail track, which can apply

significant lateral and longitudinal loads to the track structure due to thermally induced strains in the

rail.

e. The analysis of requirements for such systems must necessarily involve not only the tie but also all

components of the track system, their interdependency, and the conditions under which they must be

applied. Thus, engineered composite tie track systems involve:

(1) A well designed track structure that includes the rail, tie fastenings, ties, ballast, and subgrade.

(2) The quality of each component, installation, and maintenance.

(3) The magnitude, and frequency of traffic-imposed loads, the effect of environmental factors such as

temperature and weather, and the overall economics of installation and maintenance.

(4) The need to support and guide railway vehicles while restraining repeated lateral, vertical and

longitudinal forces.

f. The performance specifications that follow provide the basic guidance needed in the selection, design,

and application of engineered composite tie systems. Success in their application will require careful

supervision on the part of the engineer to ensure that all components meet required standards and that

the system is properly installed and maintained.

SECTION 5.2 MATERIAL

5.2.1 GENERAL (2003)

A composite is a material formed from two or more distinct materials (e.g., a polymer binder with

reinforcement in the case of polymer composites, and wood laminates bound with structural adhesive in the

case of engineered wood products) to obtain specific properties that are superior to the individual components.

5.2.2 COMPOSITE TIE TYPES (2003)

5.2.2.1 Engineered Polymer Composite (EPC) Ties

a. Polymer composite ties incorporate a polymer matrix, typically post-consumer recycled high-density

polyethylene (HDPE) as a primary component, with reinforcing fibers and/or fillers to contribute

enhanced properties. In general, polymer composite ties may be classified as one of three generic

composite types:

(1) Fiber-reinforced polymer composite – polymer reinforced with fibrous glass or other fibers, including

polymeric fibers. Fillers and other modifiers may also be added to enhance particular physical or

mechanical properties.

Ties



(2) Particle-reinforced polymer composite – polymer modified with dispersed small particles to enhance

particular physical and/or mechanical properties.

(3) Hybrid composite – a composite that incorporates two different reinforcement fibers or other

structural components (e.g., a concrete, steel, and polymer combination).

b. Each of the above-described engineered polymer composite ties has different ranges of properties, costs,

and operating characteristics. However, each type of polymer composite tie can be manufactured to meet

the established recommended performance specifications (Section 5.3 below) for use in track under AAR-

approved maximum axle loads.

5.2.2.2 Engineered Wood Product (EWP) Ties

a. EWP consists primarily of wood laminates or strands bonded together with a structural adhesive (e.g.,

phenolic). Orientation and/or placement of the wood laminates/strands is critical to the resultant

structural and physical properties.

b. The following tie types are currently considered under this specification:

(1) Glued-Laminated (Glulam) Tie – an engineered wood composite manufactured by bonding together

softwood or hardwood dimensional lumber using exterior-grade structural adhesives (e.g.,

phenolics).

(2) Parallel Strand Lumber (PSL) Tie – a structural composite lumber product manufactured using

softwood strands (typically 0.1 inch by 1 inch by 96 inch [2.54 mm by 2.5 cm by 2.44 m]) laminated

together using structural exterior adhesives (e.g., phenolics).

SECTION 5.3 PHYSICAL AND MECHANICAL PROPERTIES

5.3.1 GENERAL (2006)

Engineered composite ties shall meet the following general requirements:

a. Tie shall permit the application of standard rail, tie plate, and hold-down fasteners, such as screw spikes

or cut spikes, without requiring special procedures for installation other than ordinary predrilling of the

tie per the manufacturer’s requirements.

b. Tie shall provide an adequate flexural response to absorb train induced vibrations, while possessing

sufficient vertical compressibility to withstand rail seat loading. Tie must support imposed railroad-type

loadings while maintaining surface, line, and gage. Tie must transmit traffic loads to the ballast with

diminished contact pressures and anchor the rail-tie structure against lateral and longitudinal

movements.

c. Material surfaces shall have slip resistance equal to or better than a standard treated wood tie.

d. Tie shall not be prone to failure (e.g., cracking or fracture) due to weather-related changes in

temperature.

e. Tie shall not warp or sag to the level of permanent deformation that would require replacement of the

tie.

f. Tie shall not split or crack in anyway requiring the tie to be replaced.




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g. Material surface degradation due to solar ultraviolet (UV) radiation exposure shall not exceed 0.003 inch

(0.076 mm) per year.

5.3.2 DIMENSIONAL REQUIREMENTS (2006)

a. All measurements performed for quality assurance purposes shall be made at 73.4 +/- 2!F (23 +/- 1.1!C)

and relative humidity of 50 +/- 5%. Alternatively, measurements may be made at ambient temperature

and humidity conditions and then corrected to the specified temperature and humidity. In case of

dispute, the standard conditions shall govern.

b. For a standard gage track tie, the rail-bearing areas are those sections between 20 inches (510 mm) and

40 inches (1020 mm) from the center of the tie. Tie surface flatness in the area of the tie plate shall be

within 0.125 inch (3.18 mm).

c. Tie dimensions as specified shall be full size. All ties, without surface texturing, shall have a thickness

tolerance + 1/4 inch (6.4 mm), -0 inch (0 mm); width tolerance +/- 1/4 inch (6.4 mm); length tolerance

+3/4 inch (19 mm), -0 inch (0 mm). Ties with surface texturing shall meet nominal specified dimensions

as required for the application.

d. Standard ties, 7 inch (178 mm) by 9 inch (229 mm) by 8.5 to 9 foot (2.6 m to 2.7 m) long, without surface

texturing, will be considered straight when a straight line along each tie face from the middle of one end

to the middle of the other end is no closer to the edge of the tie than one-half the tie face dimension, plus

1/4 inch (6.4 mm) or minus 1/4 inch (6.4 mm). For ties surface textured for increased track stability, this

tolerance shall be a maximum plus 3/4 inch (19 mm) or minus 3/4 inch (19 mm).

5.3.3 PERFORMANCE REQUIREMENTS (2006)

5.3.3.1 Laboratory Testing

a. Engineered composite ties shall meet the physical and mechanical performance requirements listed in

Table 30-5-1.

b. Additional properties, and a comparison of values to various other tie materials and products, are listed

in Table 30-A-1., Mechanical Properties; Table 30-A-3., Rail Fastening System; and Table 30-A-4.,

Environmental Properties, located in Chapter 30, Appendix - Crosstie Performance Matrix.

5.3.3.2 Recommended Additional Testing

5.3.3.2.1 Field Service Testing

The performance properties listed in Table 30-5-1 are for laboratory-scale evaluations and do not represent

actual operating exposures. Engineered composite ties can be fabricated under this specfication using many

different material compositions, designs, and processing, any of which can have an affect on tie performance in

track. Compliance with the listed laboratory requirements does not necessarily assure satisfactory

performance of the ties in actual service conditions. Demonstration of field performance in actual track is,

therefore, highly recommended before any large-scale purchase and installation of any given manufacturer’s

composite ties. A field test zone of a minimum 100 ties is recommended. The ties shall be installed in a manner

that replicates standard installation practice and hardware for the particular road while conforming to any

special product specific requirements by the manufacturer (e.g., size of pre-drill). 100 million gross tons (MGT)

of traffic loading is recommended as a minimum evaluation cycle while monitoring the track conditions

including, but not limited to, unacceptable gage spreading, fastener uplift, and tie cracking or splitting.

Ties



5.3.3.2.2 Accelerated Weathering Testing

Ties can lose their serviceability not only because of wear due to mechanical loading but because of exposure to

the weather. In the early-1990’s, an empirically-based test method was developed to assess the accelerated

weathering properties of wood or wood-based ties. This method is considered to be equivalent to about 20 to 25

years of outdoor track service in the Midwest and can be found on page 82, Report No. R-702; and on page 18,

Report No. R-915, Association of American Railroads Research and Test Department (AAR). While the

exposures used in this method may or may not be the most appropriate for determining the accelerated

weathering properties of EPC ties, the method is considered a reasonable basis of comparison in the absence of

a method specifically developed for EPC ties. The test method consists of 6-cycles of exposures to vacuum-

pressure soaking, freezing, steaming, and dry-oven conditioning. The results are expressed as a percent loss of

tie mechanical properties after the exposure cycles.




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Table 30-5-1. Physical and Mechanical Properties

* Values for EWP ties include effects from pressure treatment and moisture content between 19% and

28%

TBD = to be determined

N/A = not applicable

Tie Type Polymer

Composites

Glued

Laminated*

Structural Composite

Lumber*

Modulus of Elasticity (in

3-point bending) –

MOE, psi (MPa)

Minimum,

170,000

(1,170)

calculated as

tangent modulus

per ASTM D6109

Average,

1,700,000

(11,700)

calculated per

ASTM D3737

Average,

1,740,000

(12,000)

calculated per ASTM

D5456

Modulus of Rupture –

MOR, psi (MPa)

Minimum,

2,000

(13.8)

calculated per

ASTM D6109

Minimum,

9,700

(66.9)

calculated per

ASTM D3737

Minimum,

7,800

(53.8)

calculated per ASTM

D5456

Rail Seat Compression,

psi (MPa)

Minimum,

900

(6.2)

Minimum,

650

(4.5)

Minimum

TBD

Single Tie Lateral Push,

lbf (kN), after 100,000

gross tons of traffic

Minimum,

2,500

(11.1)

Minimum,

1,800

(8.0)

Minimum,

1,800

(8.0)

Spike / Screw Pullout,

lbf (kN)

Minimum,

1,900 / 5,000

(8.5 / 22.2)

Minimum,

TBD

Minimum,

TBD

Coefficient of Thermal

Expansion, in/in/oF

(cm/cm/ oC) per ASTM

D6341

Maximum,

7.5 X 10-5

(1.35 X 10-4)

N/A N/A

Electrical Impedance,

ohms per

Article 4.9.1.14, Part 4,

Concrete Ties

Minimum,

20,000

Minimum,

10,000

Minimum,

10,000

Ties



SECTION 5.4 SPECIAL CONSIDERATIONS

5.4.1 GENERAL (2003)

In general, both polymer- and wood-based composite ties are applicable as substitutes for solid sawn wood ties

in track. While their use, handling, and installation are similar to sawn wood, some unique material properties

of these composites require special considerations for their selection and use. These special considerations are

presented in this section. Consult the manufacturer for any additional specifics.

5.4.2 FOR ENGINEERED POLYMER COMPOSITE (EPC) TIES (2006)

5.4.2.1 General

There are several manufacturers of EPC ties and their products exhibit a range of properties. The ties can be

produced in standard cross sections and lengths. The manufacturing process for EPC ties results in ties of

uniform cross-section (e.g., 7 inch [180 mm] by 9 inch [230 mm] rectangle) but virtually any desired shape can

be achieved, if required. Weight per tie is between 185 and 320 pounds (84 and 145 kg), depending on size and

composition. Certain unique characteristics of EPC ties require special considerations that may impact the

selection and design of EPC systems. These considerations are detailed below.

5.4.2.2 Thermal Properties

a. A characteristic property of EPC ties is a higher thermal expansion coefficient than wood, concrete, steel

or EWP. Theoretically, this means that EPC ties could grow longer or shorter with changes in

temperature as compared to the other tie materials for the same changes in temperature. However, field

experience in a variety of locations and climates has shown that gage is not affected to the degree

predicted by direct calculations. The specification requirement for thermal expansion ensures that rail

gage will be maintained over a wide range of operating temperatures.

b. While EPC ties will undergo, at least, some dimensional changes due to changes in temperature, it

should be noted that these changes do not occur instantaneously with the change in ambient air

temperatures. The polymer matrix materials used in these ties are inherently poor heat conductors.

While the surface of the tie may exhibit a rapid change in temperature (e.g., when exposed to direct

sunlight), the bulk of the tie will not. Changes in gage will normally not be seen as a result of changes in

temperature over a single day-to-night cycle. However, over more long-term seasonal changes in

temperature, gage dimensions will be affected – increasing as the temperature gets higher and

decreasing as the temperature gets lower – as the bulk of the tie material has time to reach a thermal

equilibrium at the new seasonal temperature.

c. If EPC ties are installed at ambient temperatures below 40 !F (4 !C) or above 100 !F (38 !C), the gage

should be adjusted by 0.125 inch (3.2 mm) (tighter at cold temperature installations, greater at high

temperatures) or as otherwise recommended by the manufacturer.

5.4.2.3 Electrical Properties

The polymer matrices used in the manufacture of EPC ties are, by their nature, excellent electrical insulators

(i.e., poor conductors). However, if metallic components are incorporated into the tie design, care must be

taken to avoid these metallic inserts during rail fastening in order to avoid rail-to-rail shorts.

5.4.2.4 Spike Withdrawal

a. Laboratory tests have shown that the force required to withdraw screw spikes from EPC ties meets or

exceeds the force required for wood ties. However, laboratory test results for the withdrawal of cut




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spikes show the forces to be initially lower for EPC ties than for wood ties (e.g., the average of several

manufacturers’ results for cut spike withdrawal exceeded 2,000 pounds-force [8.90 kN] versus 8,500

pounds-force [37.8 kN] for red oak). Other laboratory and actual service results indicate that cut spike

hold in EPC ties may not significantly deteriorate over time. In fact, over a six-cycle accelerated aging

test at the University of Illinois, the spike withdrawal strength of EPC ties actually improved 10 percent

while the oak ties decreased more than 77 percent, to 1,900 pounds-force (8.45 kN). These data

illustrate that EPC ties may have a higher hold strength than oak ties over time.

b. Actual operating data support the observation stated above and the ability of the EPC ties to hold both

cut spikes and screws. In three different installations at the Transportation Technology Center, Inc.

Facility for Accelerated Service Testing, in Pueblo, CO, and on commercial freight track, EPC ties have

carried in excess of 535 million gross tons (MGT) (4.85 x 105 gross kg) of traffic without spike or fastener

failures, and the ties continue to accumulate load.

5.4.2.5 Lateral Track Stability

EPC ties can be surface-textured for enhanced lateral stability over untextured EPC ties. As newly installed

wood ties accumulate traffic, the ballast will dig into the surface of the wood to effectively increase the overall

track stability. With an appropriately modified surface, EPC ties can immediately provide enhanced track

stability over untextured EPC ties and wood ties without the need of accumulated rail traffic. Ties can be

textured on the bottom and/or on the two sides as required for the anticipated track application. Based on

single-tie lateral push-out tests performed by various laboratories including TTCI, EPC ties without the

surface texturing have not exhibited increased lateral track stability from that achieved during initial tie

installation even after high traffic loading. EPC ties without surface texturing maintained a 2,000 lbf (8.9 kN)

or less push-out force even after 15 MGT (1.36 x 104 gross kg) of traffic. With surface texturing, this push-out

force increased to 4,000 lbf (17.8 kN) or more without any accumulated traffic tonnage. Use of surface-

modified ties is particularly recommended with welded-rail track, which can apply significant lateral and

longitudinal loads to the track structure due to thermally induced strains in the rail.

5.4.2.6 Preservative Treatment

EPC ties are inherently resistant to rot and insects and, therefore, do not require additional treatment

processes.

5.4.2.7 Machining

Typically, EPC ties can be bored, branded, incised, or trimmed with the same machinery and processes as used

for sawn lumber ties. The manufacturer’s recommendations should be followed.

5.4.2.8 Tie Plugs

Tie plugging material may be used in EPC ties basically in the same fashion as they are used in sawn ties.

Polymer-based plugging compounds (e.g., polyurethane) are recommended.

5.4.2.9 Anti-Splitting Devices

Anti-split devices are not required for EPC ties.

5.4.2.10 Disposal

The thermoplastic matrix of most manufactured EPC ties increases the probability that worn out or damaged

EPC ties can be recycled into the manufacturing process to make new EPC ties. Consult the manufacturer

regarding specific recycling options. Federal, State, and local regulations may also influence the ultimate

disposal method.

Ties



5.4.3 FOR ENGINEERED WOOD PRODUCT (EWP) TIES (2006)

5.4.3.1 General

By virtue of their wood-based composition, EWP ties behave similar to solid sawn wood ties in many respects.

However, because they are engineered composites, they also have some unique properties that can impact the

selection and design of EWP systems. These considerations are detailed below.

5.4.3.2 Adhesives

Adhesives shall be suitable for use with wood in exterior structural applications. Adhesives shall meet the

requirements of ASTM D 2559.

5.4.3.3 Species

EWP ties may be of any wood species provided that the manufacturer certifies the minimum mechanical

properties of EWP product.

5.4.3.4 Preservative Treatment

EWP ties may have physical properties that differ from sawn lumber ties. These differences (e.g., permeability)

may influence the material’s treatability, and, therefore, specialized treatment processes may be required.

EWP ties shall be treated in accordance with the manufacturer’s recommendations.

5.4.3.5 Strand/Laminate Orientation

EWP ties have a distinct strand/laminate orientation not seen in sawn timbers (Figure 30-5-1). The orientation

influences mechanical and structural properties, and it results in different surface characteristics and

appearance. It is important to follow manufacturer’s recommendations with regard to orientation, particularly

with square members such as bridge ties.

5.4.3.6 Machining

Typically, EWP ties can be adzed, bored, branded, incised, or trimmed with the same machinery and processes

as sawn lumber ties. The manufacturer’s recommendations should be followed.

Vertical

Laminations

Horizontal

Laminations

Figure 30-5-1. Engineered Wood Product Orientations




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5.4.3.7 Tie Plugs

Tie plugging material may be used in EWP ties in the same fashion as in sawn ties. The specifications for

wooden tie plugs are located in Article 3.1.5.

5.4.3.8 Anti-Splitting Devices

The need for anti-split devices on EWP ties may vary. Consult the manufacturer for recommendations. If

required, use of anti-splitting devices shall be in accordance with Article 3.1.6 and Article 3.1.7.

5.4.3.9 Inspection

EWP ties may contain fewer knots, shakes, splits, checks, slope of grain, or bark seams than sawn ties.

Inspection of EWP ties should be in accordance with Article 3.1.1.4.

5.4.3.10 Disposal

Treated EWP ties can be disposed of in the same manner as conventional wood ties. Federal, State, and local

regulations may dictate acceptable disposal methods.

SECTION 5.5 QUALITY CONTROL, INSPECTION, AND IDENTIFICATION

5.5.1 PRODUCTION QUALITY CONTROL (2006)

5.5.1.1 General

The manufacturers of engineered composite ties shall have a quality assurance program to verify appropriate

portions of this specification. At a minimum, the program shall include the following:

a. Material Specification, including incoming material inspection and acceptance requirements.

b. Sampling and inspection frequencies shall be devised to encompass all variables that affect the quality of

the finished product including lot-to-lot variations from different production runs. Increased

frequencies shall be used in connection with new or revised facilities. A random sampling scheme shall

generally be used for specimen selection. As a minimum, properties to be verified in the Quality

Assurance program shall include:

(1) Dimensional Requirements, Article 5.3.2

(2) Modulus of Elasticity and Modulus of Rupture, Article 5.3.3, Table 30-5-1

NOTE: Depending on composition and fabrication process, EPC ties will contain internal voids not

visible to the naked eye, particularly in the center of the cross-section. An evenly distributed

fine foam in the center cross-section is considered normal. However, large internal voids can

occasionally form that can negatively affect tie performance. Since such internal voids may not

be obvious upon inspection of the outside of the tie - including the ends, manufacturers of EPC

ties are encouraged to develop procedures to screen finished ties for these unacceptable internal

voids.

c. Procedures to be followed upon failure to meet specifications or upon out of control conditions shall be

specified. Included shall be reexamination crieteria for suspect material and material rejection criteria.

Ties



d. Finished product marking, handling, protection, and shipping requirements as they relate to the

performance of the finished producct shall be defined.

5.5.1.2 Inspection Personnel

All manufacturing personnel responsible for quality control shall have knowledge of the inspection and test

procedures used to control the process of the operation and calibration of the recording and test equipment

used and of maintenance and interpretation of quality control records.

5.5.1.3 Record Keeping

All pertinent records shall be maintained on a current basis and be available for review. Records shall include:

a. Inspection reports and records of test equipment calibration, including indentification of personnel

conducting tests.

b. All test data, including re-testing and data associated with rejection production and corrective actions

taken.

5.5.1.4 Retest and Rejection

If the results of any selected quality tests do not meet the requirements, the test(s) may be conducted again in

accordance with statistically valid sampling techniques as agreed upon between the purchaser and the seller.

There shall be no agreement to lower the minimum requirements or omitting tests that form a part of this

specification, substituting or modifying a test method or by changing the specification limits. In retesting, the

product requirements of this specification shall be met. If upon retest failure occurs, the quantity of product

represented by the tests(s) shall be rejected.

5.5.2 TIE IDENTIFICATION AND RECORDS (2006)

Finished ties will permanently identify the manufacturer and year and month of production. In addition,

product shipments will be traceable to the year, day, production line, and operating shift that produced the ties.

5.5.3 CERTIFICATION (2006)

When requested, a manufacturer’s cerfication and any other documents required to substantiate certification

shall be furnished stating that the ties were manufactured to meet this specification.

Documents

Arema Cap. 30 (Part 5) - Composite Ties