BS 13230-4:2016 pdf download – Railway applications — Track — Concrete sleepers and bearers Part 4: Prestressed bearers for switches and crossings
1 Scope
This part of the EN 13230 series defines additional technical criteria and control procedures as well as specific tolerance limits related to manufacturing and testing prestressed bearers for switches and crossings with a maximum length of 8,5 m.
Bearers longer than 8,5 m are considered as special elements and are covered by EN 13230-5:2016.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN 206, Concrete – Specification, performance, production and conformity
EN 13230-1:2016, Railway applications – Track – Concrete sleepers and bearers – Part 1: General requirements
FprEN 10138 (all parts), Prestressing steels
3 Terms, definitions and symbols
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 13230-1:2016 and the following apply:
prestressed monoblock bearer
bearer manufactured using pre-tensioned or post-tensioned tendons
characteristic positive bending moment
M k,pos
positive bending moment at any position of the bearer
characteristic negative bending moment
M k,neg
negative bending moment at any position of the bearer
4 Special requirement
4.1 Characteristic bending moments
The bearer shall be designed with positive and negative characteristic bending moment capacities with the objective of keeping it straight.
4.2 Positioning of fastening components
An area of the concrete section shall be specified by the purchaser to be free from prestressing tendons for the location of fastening components.
If required by the purchaser, the design of the bearer shall provide for the repair or replacement of the embedded fastening components.
4.3 Tolerances
4.3.1 General
The maximum tolerances specified in EN 13230-1:2016, 6.1 apply to concrete bearers.
In case of early dimensional inspection of the concrete element, the quality plan shall take into account further shortening of the element. Measurement of tolerances shall be checked not before 48 h after transfer of prestressing forces.
4.3.2 Tolerance of planeness
The maximum deviation of the total rail seat or base plate area is as follows:
— planeness: 1 mm;
— variation of planeness with regard to 2 points 150 mm apart: 0,5 mm.
4.3.3 Tolerances of fastening positioning
The tolerances of the embedded fastening components positioning shall be measured in accordance with Figure 1.
Vertical deviation in both directions is measured on a 3,6 m long base as on Figure 2.
Alternative measurement methods can be proposed by the manufacturer and agreed with the purchaser.
Bearers shorter than 4 m need not be checked.
Maximum allowed deviation is 3 mm on a 3,6 m base.
For bearer length above 6 m, maximum allowed deviation is agreed between supplier and purchaser.
4.4 Distance from the end of the bearer to the nearest cast-in component
The supplier defines the prestress anchoring area and special care to be taken into account for cast-in components near to the end of the bearer.
5 Product testing
5.1 General
This section defines the testing regime and rules for acceptance of concrete bearers.
The layouts of the test arrangements are defined in this section.BS 13230-4 pdf download.