Research on the Bearing Performance of Prefabricated New Type Subway Track Slab with Basalt Fiber

Abstract

Currently, most ballastless tracks in Chinese subways are traditional cast-in-situ concrete structures, which require long construction progress. In contrast, prefabricated ballastless tracks can greatly reduce the construction period. However, there are few theoretical and experimental analyses on the prefabricated new type of subway slab track. Hence, to study the mechanical properties of the new type of subway track slab, static bending crack tests of one standard slab track and nine prefabricated full-scale track slabs with basalt fiber were carried out in this paper. The influence of the reinforcement arrangement method and the basalt fiber content on the performance of the track slabs was studied. Results showed that with the increase in the basalt fiber content in the range of 0.1–0.3%, the load–strain curve growth rate increased, the stiffness decreased, and the flexural resistance reduced. All the specimens exhibited a linear portion (elastic) and then a nonlinear portion (plastic) followed by flexural failure. During the elastic stage, the basalt fiber helped to improve the rigidity of the track slab. During the plastic stage, the influence of the basalt fiber content on the failure load varied with different reinforcement arrangements. With the reinforcement arrangement F2 and 0.1% basalt fiber content, the specimen had the smallest load–strain curve growth rate and the best overall flexural performance and crack resistance, and its strain was 23.35 με at an elastic limit of 95 kN. The results can provide a reference for the design of the prefabricated slab ballastless track.

Keywords

New type subway track slab / Basalt fiber / Static load bending test / Reinforcing bars / Cracks / Deflection

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Funding

National Key Research and Development Program of China(2021YFB2601000)

Natural Science Foundation of Shaanxi Province(2021JQ-255)

Postdoctoral Research Foundation of China(2016M601312)