Concrete for precast slab track filling layer as well as preparation method and application of concrete

Abstract

The invention provides a steel fiber fine stone concrete material for a precast slab track filling layer. The steel fiber fine stone concrete material is prepared by mixing water, cement, sand, stone,mineral powder, fly ash, steel fibers and a water reducing agent. The steel fiber fine stone concrete has the beneficial effects that the steel fiber fine stone concrete prepared according to the component proportion of the concrete for the filling layer of the prefabricated slab track has excellent fluidity, and the slump of the concrete is 200 mm+ / -20 mm. During construction, a conveying hopperis adopted for continuous pouring from one side of a track plate or in a pouring hole in the track plate, a vibrating rod can be adopted for proper vibrating from the pouring hole or the two sides ofthe track plate according to needs in the pouring process, bubbles in concrete can be discharged from a reserved hole and the edge of the track plate, and good compactness can be obtained. On the other hand, the fatigue compressive strength under the repeated action of long-term fatigue load (namely train load) can be obviously improved, and it is predicted that the compressive fatigue life of the concrete for the precast slab track filling layer can be prolonged 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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