Composite railroad ties are also called synthetic sleepers. It is created to substitute traditional timber railroad ties and concrete ties. Wooden sleepers are easy to rot, break, and have a short service life. A lot of maintenance work is needed resulting in higher cost. Besides, the exhaustion of wood resources urgently needs to be controlled and protected. According to calculation, using one FFU synthetic sleeper can reduce the amount of wood used by one cubic meter. The concrete sleeper is heavy and can’t be installed in a special section of the railroad track. On the contrary, composite railroad ties are lightweight, eco-friendly (can be recycled) and have many other advantages.
Application of composite railroad ties
First developed by Japan’s Sekisui Chemical in the late-1970s, the synthetic sleeper has now been more and more used on all types of rail transport system, particularly on switches, turnouts, bridges and other projects in high-speed and metro railway construction.
AGICO manufactures first-class synthetic sleepers approved by authorities. Our patented products have been installed on many metro systems in Taiwan, Hong Kong, Guangzhou and Nanjing, etc. AGICO’s composite railroad ties can be used the equivalent of Japan Sekisui sleepers, but with a more competitive price.
In the past years, AGICO has cooperated with many metro companies in FFU synthetic sleeper projects in and outside China. The high performance and low cost and excellent after-sales service have gained the approval of our clients.
Advantages of composite railroad ties
- Lightweight with high strength, insulation and corrosion resistance.
- Less water absorption, better electrical insulating property, better resistance to ultraviolet ageing and corrosion, better oil resistance, heat resistance and fire resistance.
- Long-period strength and dimensional accuracy maintenance.
- The field processing (fluting, drilling, abrade, nailing, bonding and varnishing) of synthetic sleeper is easier than that of wood.
- High spike and screw pull-out strength for the new or repaired sleeper.
- High antifatigue ability and durability.
The material of composite railroad ties
The composite railroad ties are mainly referred to as FFU synthetic sleeper or Fiber-reinforced Foamed Urethane synthetic sleeper. It is made of rigid polyurethane reinforced with continuous glass fiber through a pultrusion process. Main materials contain continuous glass fiber, polyether polyol, isocyanate and related components. Using fiber/glass-reinforced composite materials can get high insulation and corrosion resistance to avoid chemical or biological corrosion. The appearance of the FFU synthetic sleeper is similar to a wooden sleeper. It has all the advantages of wood and plastic sleeper.
Studies have shown that the physical properties of FFU synthetic sleepers have hardly changed after 15 years of application. In Japan, FFU synthetic sleepers have been successfully used for nearly 20 years. Compared with concrete turnout sleepers, FFU has good flexibility and helps reduce vibration and noise. It can adapt to high-speed tracks even without rail pads. Its specific gravity is only one-third of that of concrete. Also, FFU materials can be recycled. After FFU waste is crushed and pressurized, new recycled products can be made.
Properties of FFU synthetic sleeper Made by AGICO
|JIS E1203:2007 Strength||(CJ/T399-2012)|
AGICO Sleeper Strength
|Material Strength||Bending Strength||min. 70 N/mm2||min. 80 N/mm2|
|Young’s modulus in flexure||min. 6000 N/mm2||min. 7000 N/mm2|
|Withstand bending load||min. 170 kN||min. 170 kN|
|Longitudinal compressive strength||min. 40 N/mm2||min. 50 N/mm2|
|Shearing strength||min. 7 N/mm2||min. 7 N/mm2|
|Adhesion shearing strength||min. 7 N/mm2 (base-material breakage)||min. 7 N/mm2 (base-material breakage)|
|Electrical Properties||Alternating-current breakdown voltage||min. 20 kV||min. 20 kV|
|Direct-current insulation resistance||min. 1 X 1010 Ω||min. 1 X 1010 Ω|
|Pulling Strength||Track spike pulling strength||min. 15 kN||min. 20 kN|
|Screw spike pulling strength||min. 30 kN||min. 40 kN|
|0.74± 0.1 g/cm3||0.74± 0.1 g/cm3|
|max. 10 mg/cm2||max. 10 mg/cm2|
Synthetic sleeper processing
AGICO supplies synthetic sleepers that comply with domestic or foreign standard size (any dimensions based on customer’s request). We can machine groove on the side of the sleeper, drill hole on the top of the sleeper or any other shapes as the customer’s design.
FFU synthetic sleepers can also be pre-fabricated with rail to be installed on-site rapidly. It can be processed on-site to ensure installation accuracy and speed.