Large-radius chamfered sleeper for ballastless track concrete crack control and its construction method

Abstract

The invention provides a large-radius chamfer sleeper used for controlling concrete cracks of a ballastless track and a construction method. In the large-radius chamfer sleeper, (1), large-radius chamfers are used for the corners of the sleeper, the chamfer part is equivalent to a quarter of a circular platform, and the radius of the top of the circular platform is generally not less than 80mm; (2), crack-proof steel bars are arranged on the periphery of the sleeper, wherein the crack-proof steel bars can be arranged to form a closed loop along the outer side of the sleeper or to form loops only in certain ranges of the ends of the sleeper, and ribbed steel bars with nominal diameters being 14mm-20mm are utilized as the crack-proof steel bars; (3), when the grade of the carbonation environment effect is T2, the thicknesses of the protection layers of the crack-proof steel bars are 35mm, and when the grade of the carbonation environment effect is T3, the clear spacings between the crack-proof steel bars and the sleeper are 20mm-30mm; (4), during the construction of the large-radius chamfer sleeper, fixing position accuracy in the whole track bed and soundness of the crack-proof steel bars need to be guaranteed, and meanwhile, the crack-proof steel bars need to be separated from other steel bars.

Description

technical field [0001] The invention relates to the construction technology of high-speed railway ballastless track concrete. Background technique [0002] Ballastless track is commonly used in high-speed railways, which is a track structure with high stability, high ride comfort and less maintenance, and has the characteristics of concrete structure. However, concrete cracking is extremely difficult to control during the construction and operation of the ballastless track's integral ballast slab, especially in Northwest my country. Because the integral track bed slab itself is equivalent to a reinforced concrete slab with a relatively small body surface, coupled with the characteristics of drought, strong wind, and large temperature difference between day and night in the northwest region, all of which have a great impact on the shrinkage of concrete in the early stage of setting and hardening and the shrinkage in the later stage, as well as the resulting Concrete cracking...

AI Technical Summary

Problems solved by technology

For the square-end sleepers used at this stage, because the chamfering radius of the corners is too small, it is very easy to cause stress concentration at the corners of the sleeper due to the shrinkage of the concrete of the integral track bed slab in the early stage of setting and hardening and the shrinkage of the concrete in the later stage. As a result, the overall track bed slab has a figure-eight crack at the corner of the sleeper

This kind of cracking will reduce the bearing capacity and durability of the overall track bed

In severe cases, the entire track bed may even be dismantled and reworked due to concrete cracking

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