The Research On Construction Technology And Rapid Repairing Materials For Ballastless Track Of High-speed Railway

The durability and smoothness of ballastless track structure are the main factors affecting the operation safety of high-speed railway.However,the gap between ballastless track slab and mortar layer resulted from the stress concentration of slab-type high-speed railway track occurs from time to time.Based on the foreign maintenance experience of ballastless track,this paper develops the technology and materials used in China's high-speed railway for repairing the gap between ballastless track slab and mortar layer.This paper introduces the construction technology of the CRTS II type non-rolling track and the cement emulsified asphalt mortar filling layer;shows the causes of latter fractures resulted from inadequate construction technology;makes suggestions on the improvement of construction technology.Based on the realities of laying construction of ballast and track slab,the timely maintenance and repair on the fractures and traditional technology are necessary for preventing the generation of latter fracture and reducing the maintenance cost.A suitable theoretical mix ratio is proposed by repeated laboratory tests on the cement emulsified asphalt mortar.The optimum construction mix ratio is obtained by actual construction.The performance of cement emulsified asphalt mortar filling layer reaches its optimal state through the repeated uncovering tests.A fast repairing cement mortar was developed.Its distribution formula is as follows: fast hardening sulphoaluminate cement 22,magnesia 8,fly ash 10,sand 40,polyphosphate 5,polypropylene fiber 0,latex powder 0.8 and water 10.The 1-hour and 4-hour compressive strengthes are 40 MPa and 49.2MPa,respectively.The 8-hour compressive and flexural strengthes are 54.8MPa and 16.3MPa,respectively,and the corrosion resistance is above 0.91.The indexes of the fast repairing cement mortar meet the requirements of the construction of the slab ballastless track.