A kind of concrete for prefabricated slab track filling layer and its preparation method and application

Abstract

The invention provides a steel fiber fine stone concrete material for prefabricated slab track filling layer, which is prepared by mixing water, cement, sand, stone, mineral powder, fly ash, steel fiber and water reducer. The beneficial effects of the present invention are: the steel fiber fine stone concrete configured according to the component ratio of the concrete for the prefabricated slab track filling layer of the present invention has excellent fluidity, and the concrete slump is 200mm±20mm. During the construction, the transport hopper is used to pour continuously from the side of the track slab or the pouring hole in the track slab. During the pouring process, the vibrating rod can be used to vibrate properly from the pouring hole or both sides of the track slab as needed. The air bubbles in the concrete can be pre-filled. Holes are left and the edge of the track plate is discharged to obtain good compactness. On the other hand, it can significantly improve the fatigue compressive strength under repeated long-term fatigue loads (ie, train loads), and is expected to increase the compressive fatigue life of concrete used for precast slab track filling layers by 7.9-13.7 times.

Description

technical field [0001] The invention belongs to the field of building engineering materials, in particular to a concrete for a prefabricated slab track filling layer, in particular to a steel fiber fine stone concrete for a prefabricated slab track filling layer. Background technique [0002] The track structure directly bears the train load and transmits the load to the lower tunnel lining, which is the key to connecting the preceding and the following, ensuring operational safety and passenger comfort. When laying the traditional prefabricated slab track, first, the reinforced concrete structure is poured on the inner wall of the tunnel to form a base, then the precast slab is erected on the base, self-compacting concrete is poured in the space between the prefabricated slab and the base, and the steel mesh is laid to form a self-contained tunnel. Dense reinforced concrete fill layer. Ultimately, the infill layer together with the substrate will form the basis for the tra...

AI Technical Summary

Problems solved by technology

This method has the following problems during construction: (1) It is necessary to arrange reinforcement mesh in the filling layer and place it directly under the track slab; (2) The reinforcement mesh needs to be fixed, and it is easy to deviate during pouring; (3) Self-compacting concrete After drying, the self-compacting shrinkage is relatively large, and cracks are easy to occur, and the reinforcement cannot cope with the shrinkage cracks; (4) the self-compacting concrete will lose its flexural strength after cracking; High; (6) The unit price of self-compacting concrete materials is high

This method has the following problems during construction: (1) The aggregate particle size is large, the cementitious material is less, and the natural fluidity is limited; (2) The bending and tensile strength is lost after cracking, and steel mesh is required; (3) Ordinary concrete It will shrink and cause cracks, and the reinforcement cannot cope with the shrinkage cracks; (4) The reinforcement mesh needs to be fixed, and it is easy to deviate from the design position during pouring; (5) The reinforcement mesh hinders the flow of ordinary concrete, and it is easy to produce hollowing, Air bubbles, affecting the quality of the filling layer

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