Sleeper structure and construction method for bonding old and new concrete for ballastless track

Abstract

The invention provides a sleeper structure and construction method for bonding old and new concrete on a ballastless track. The sleeper is divided into the upper part and the lower part in the cross section, the upper part 1 is in a rectangular shape, the length of the upper part 1 is l1 and the height of the upper part 1 is h1. The step-slope upper part 2 of the sleeper is in an isosceles trapezoid shape, the upper side of the upper part 2 is longer than the lower side of the upper part 2, that is, for the lower part of the sleeper, the adopted gradient of a bottom surface step-slope part side 4 of a step slope toward the inside is 1:1; the length of the upper side of the isosceles trapezoid is l1, the length of the lower side is l2, the horizontal length l2 of a sleeper bottom surface 5 is controlled to 8-10 cm, the height h2 of the lower part 2 is shown as follows: h2=(l1-l2) / 2, and the total height h3 of the cross section of the sleeper is as follows: h3=h1+h2. The construction method includes the steps of 1, preparing a sleeper mold, 2, connecting steel bars in the sleeper and the sleeper with truss bars, 3, pouring sleeper concrete, 4, processing reinforcing steel bars of the whole roadbed slab according to a design drawing, 5, bundling the reinforcing steel bars of the whole roadbed slab, 6, conducting concrete pouring on the whole roadbed slab, 7, maintaining the concrete, 8, disassembling formworks and tool rails.

Description

technical field [0001] The invention relates to the field of new and old concrete bonding crack control for ballastless track sleepers and ballast beds of high-speed railways. 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, in the construction and operation of ballastless track, the bonding crack between the sleeper and the old and new concrete of the integral ballast bed is a very difficult problem to control, especially in the northwest region of my country. For concrete sleepers, the side surface is smooth, which is not conducive to the bonding of old and new concrete; and its bottom surface is approximately a plane. When the overall track bed is constructed, the air bubbles in the concrete of the track bed at the lower part of the sleeper will gather under vibration. The bottom of the...

AI Technical Summary

Problems solved by technology

For concrete sleepers, the side surface is smooth, which is not conducive to the bonding of old and new concrete; and its bottom surface is approximately a plane. When the overall track bed is constructed, the air bubbles in the concrete of the track bed at the lower part of the sleeper will gather under vibration. The bottom of the sleeper cannot be discharged, which will form a gap between the sleeper and the concrete of the integral track bed and cannot be bonded, and the concrete of the integral track bed will sink when the concrete hardens and shrinks, and the sleeper cannot sink under the fixation of the tool rail, resulting in The gap between the sleeper and the integral ballast bed further increases

In Northwest China, due to drought, strong winds, and large temperature differences between day and night, the shrinkage of concrete will further intensify, which will further increase the cracks between the overall ballast bed and concrete, reduce the integrity of the ballastless track structure, and affect its stress. performance and durability

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