1 Scope
This document specifies the technical requirements, test methods, inspection rules, marking, packaging, storage, and transportation of the concrete sleeper with under sleeper pads for railway ballasted track (including the turnout sleeper).
This document is applicable to the concrete sleeper with under sleeper pads for railway ballasted track (hereinafter referred to as "elastic sleeper").
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 528 Rubber, vulcanized or thermoplastic - Determination of tensile stress-strain properties
GB/T 1690 Rubber, vulcanized or thermoplastic - Determination of the effect of liquids
GB/T 2828.1 Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection
GB/T 3512 Rubber, vulcanized or thermoplastic - Accelerated aging and heat resistance tests
GB/T 7762 Rubber, vulcanized or thermoplastic - Resistance to ozone cracking - Static strain testing
GB/T 9258.1-2000 Coated abrasives - Grain size analysis - Part 1: Grain size distribution test
GB/T 10654 Flexible cellular polymeric materials - Determination of tensile strength and elongation at break
GB/T 37330 Sleeper for ballasted track - Concrete sleeper
TB/T 3080 Concrete turnout sleeper for ballasted track
3 Terms and definitions
No terms and definitions are listed in this document.
4 Technical requirements
4.1 General requirements
4.1.1 The elastic sleeper consists of two parts: a concrete sleeper and an elastic pad under the sleeper. See Figure 1 for the schematic diagram of the elastic sleeper. The elastic pad under the sleeper includes a bonding layer (or structure) and an elastic layer.
Key:
1——Concrete sleeper; 2——Elastic pad under the sleeper.
Figure 1 Schematic diagram of the elastic sleeper
4.1.2 The elastic sleeper and its components shall be manufactured according to the design drawings and this document.
4.1.3 The elastic sleeper and its components shall be produced in a factory which has the necessary tooling equipment and mature production technology.
4.2 Elastic pad under the sleeper
4.2.1 Raw materials shall meet the following requirements:
a) The main raw material of the elastic pad under the sleeper should be EPDM rubber and polyether polyurethane. When the elastic pad under the sleeper is made of other materials, its performance shall not be lower than that specified in this document; and recycled materials shall not be used;
b) All raw materials shall be provided with the manufacturer's certificate of conformity.
4.2.2 The type and dimension of the elastic pad under the sleeper shall meet the requirements of the design drawing and the limit deviation shall meet those specified in Table 1. The elastic pad under the sleeper shall not be spliced.
Table 1 Requirements for limit deviation of the elastic pad under the sleeper In: mm
S.N. Item Limit deviation
1 Length ±5
2 Width ±3
3 Thickness ±1.0
4.2.3 The surface of the elastic pad under the sleeper shall be clean and smooth without peeling or delamination. The edges of the elastic pad under the sleeper shall be trimmed neatly. Other appearance qualities of the EPDM rubber and polyether polyurethane elastic pads under the sleeper shall meet those specified in Table 2 and Table 3 respectively.
Table 2 Requirements for appearance qualities of the EPDM rubber elastic pad under the sleeper
S.N. Item Requirement
1 Corner defect The sum of the lengths of the three sides of the missing corner shall not be greater than 6 mm
2 Glue shortage The length of glue shortage caused by impurities, bubbles, watermarks, and trapped air shall not be greater than 3 mm, and the depth shall not be greater than 0.5 mm; and there shall be not more than 3 glue shortage parts, and the repaired ones shall be considered as defects.
3 Sponge There shall be not more than 2 sponges with a length greater than 3 mm on the working surface
4 Crack There shall be no visible cracks
Table 3 Requirements for appearance qualities of the polyether polyurethane elastic pad under the sleeper
S.N. Item Requirement
1 Corner defect The sum of the lengths of the three sides of the missing corner shall not be greater than 6 mm
2 Pit The length of a single pit shall not be greater than 15 mm, the width shall not be greater than 5 mm, and the depth shall not be greater than 0.5 mm; and there shall be not more than 3 pits per piece
3 Pitted surface There shall be not more than 2 pitted surfaces with a diameter greater than 3 mm on the working surface
4 Crack There shall be no visible cracks
4.2.4 The physical properties of EPDM rubber and polyether polyurethane elastic pads under the sleeper shall meet those specified in Table 4 and Table 5 respectively.
Table 4 Requirements for physical properties of the EPDM rubber elastic pad under the sleeper
S.N. Item Requirement
1 Tensile strength
MPa ≥ 12
2 Elongation at break ≥ 250%
3 Hot air aging (70°C, 168h) Tensile strength
MPa ≥ 10
Elongation at break ≥ 200%
4 Alkali resistance [saturated Ca (OH)2 solution, 24h, 23°C] volume change rate ≤ 5%
5 Ozone aging resistance (50 × 10-8, 20%, 40°C, 96h) Without crack
Table 5 Requirements for physical properties of the polyether polyurethane elastic pad under the sleeper
S.N. Item Requirement
1 Tensile strength
MPa ≥ 2.5
2 Elongation at break ≥ 150%
3 Hot air aging (70°C, 168h) Tensile strength
MPa ≥ 2
Elongation at break ≥ 125%
4 Alkali resistance [saturated Ca(OH)2 solution, 24h, 23°C] volume change rate ≤ 5%
5 Ozone aging resistance (50 × 10-8, 20%, 40°C, 96h) Without crack
4.2.5 The static modulus of the elastic pad under the sleeper shall meet the design requirements.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Technical requirements
5 Test methods
6 Inspection rules
7 Marking, packaging, storage and transportation
Annex A (Normative) Test methods for the static modulus of the elastic pad under the sleeper
Annex B (Normative) Test methods for the contact area ratio of the elastic pad under the sleeper
Annex C (Normative) Test methods for freeze-thaw cycles of the elastic pad under the sleeper
Annex D (Normative) Test methods for the fatigue performance of the elastic sleeper
Annex E (Normative) Test methods for peel strength test of the elastic sleeper
