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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard was proposed by and is under the jurisdiction of National Railway Administration of the People's Republic of China.
Sleeper for ballasted track -
Concrete sleeper
1 Scope
This standard specifies the technical requirements, inspection methods, inspection rules, marking, storage and transport of prestressed concrete sleeper for ballasted track.
This standard is applicable to prestressed concrete sleeper for ballasted track for standard gauge railways (excluding turnout sleepers, hereinafter referred to as sleepers).
2 Normative references
The following referenced documents are indispensable for the application 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 1499.1 Steel for the reinforcement of concrete - Part 1: Hot rolled plain bars
GB/T 5223 Steel wires for prestressed concrete
TB/T 1878 Fatigue test method for prestressed concrete sleeper
TB/T 1879 Test method for crack resistance of prestressed concrete sleeper under static load
TB/T 3275 Concrete for railway construction
TB 10425 Standard for evaluation of railway concrete strength
YB/T 5294 Low carbon steel wire for general purpose
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
shoulder with oil penetrating
defects caused by grease-like substances penetrating the shoulder of the sleeper
3.2
pulverulent shoulder
looseness of shoulder of sleeper due to slurry leakage
3.3
bumped shoulder
defects caused by bumping on sleeper shoulder
3.4
exposed reinforced steel
exposure of reinforced steel inside of the sleeper which shall be wrapped by concrete
3.5
sleeper that have capacitor's mounting groove
sleepers that have track circuit capacitor's mounting groove
4 Technical requirements
4.1 Material
4.1.1 Portland cement or ordinary portland cement shall be used. The strength grade of cement shall not be inferior to Grade 42.5, early-strength cement shall not be used, the alkali content shall not be greater than 0.60%, the content of sulfur trioxide shall not be greater than 3.0%, and other technical requirements shall meet those specified in TB/T 3275.
4.1.2 The aggregate shall meet the following requirements:
a) Continuously graded crushed stone of two grades, i.e., 5 mm~10 mm and 10 mm~25 mm, should be adopted as the aggregate, and the particle size shall be 5 mm~20 mm if the railway design speed is greater than 200 km/h or 5 mm~25 mm if the railway design speed is less than or equal to 200 km/h. The broken surface of crushed pebbles, if used, shall be greater than 70%, and other technical requirements shall meet those specified in TB/T 3275.
b) The natural medium-coarse river sand shall be adopted as fine aggregate, with the silt content not greater than 1.5% when counted by mass, and other technical requirements shall meet those specified in TB/T 3275.
c) Aggregates with alkali-carbonate reactivity or alkali-silicic acid reactivity with a mortar bar expansion rate (accelerated method) greater than or equal to 0.20% shall not be used. The alkali activity of aggregate shall be tested and evaluated by the qualified inspection unit according to the method specified in TB/T 3275 before the sleeper is put into production, annually during normal production or when the aggregate source changes.
4.1.3 Mixing water shall meet those specified in TB/T 3275.
4.1.4 Water reducer shall meet those specified in TB/T 3275.
4.1.5 Mineral additive shall meet those specified in TB/T 3275.
4.1.6 The steel shall meet the following requirements:
a) The prestressed wire shall meet those specified in GB/T 5223.
b) The performance of stirrup shall meet those specified in GB/T 1499.1 if hot rolled plain bar is adopted or meet those specified in YB/T 5294 with the performance of steel used not inferior to the requirements for Q 235 if low carbon cold-drawn steel wire is adopted.
c) The performance of spiral bar shall meet those specified in YB/T 5294 if low carbon cold-drawn steel wire is adopted.
4.1.7 Embedded fasteners (including embedded casing and embedded iron pedestal) shall meet relevant technical requirements.
4.1.8 All raw materials (excluding aggregate) and embedded fasteners shall be accompanied with manufacturer's end-of-manufacturing certificate and re-inspection report, and aggregate shall be accompanied with incoming inspection report.
4.2 Manufacture
4.2.1 Prestressed wire shall be tensioned by automatic tensioning equipment. The total tensile force and deviation shall meet the design requirements; if the deviation for total tensile force is not specified in the design, the deviation for total tensile force shall not be greater than 1.5% of the design value.
4.2.2 When prestressed reinforced steel are blanked, grouped or tensioned, it shall be ensured that each prestressed wire is subjected to uniform force. If long-line pedestal method is adopted for production, the single piece partial tension technology shall be adopted, and the difference between the maximum and minimum tensile forces between prestressed wires with the same sleeper shall not be greater than 5% relative to the design value; if machine-stand flow method is adopted for production, the deviation of the blanking length of the steel wire shall not be greater than 1.5/10000 of the length of the steel wire.
4.2.3 The tension of prestressed wire shall be carried out according to the following procedure: 0 → total tensile force → holding load for not less than 1 min → locking the nut.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Technical requirements
5 Inspection methods
6 Inspection rules
7 Marking, storage and transport
Annex A (Normative) Method for testing the pull-out resistance of embedded fasteners