TB/T 2286.2-2015 in English

TB/T 2286.2-2015 standard replaces the 2008 version and puts forward comprehensive technical requirements for annular prestressed concrete pillars used in electrified railway contact networks. The key revisions include:

• Added T-type pillars with deflection ≤25mm at the guide height
• Improved the durability index of concrete (frost resistance grade F300, electric flux <1000C)
• Strengthened the thickness requirement of the protective layer in the anchorage area of the main reinforcement at the flange end (≥13mm)

1. Raw material requirements

• Cement: ≥42.5 grade silicate cement, alkali content ≤0.6%
• Aggregate: crushed stone crushing index ≤10%, mud content ≤0.5%
• Steel: prestressed tendons adopt GB/T 5223 standard steel wire

2. Production process

1. Steam curing system: temperature rise ≤20℃/h, constant temperature 60℃±5℃
2. Tensioning control: main reinforcement force deviation <1.5%
3. Appearance defects: crack width <0.2mm, leakage length <300mm

Selection guide

Select the support type according to the line conditions:

• T-type support: Suitable for harsh environments such as windy areas/high cold
• Ordinary support: More economical for general lines

Installation precautions

The two-point method should be used for transportation and storage, and the inter-layer pads should be aligned. When installing flange-type pillars, ensure that the foundation level deviation is less than 3mm.