Polymer cement mortar for slab ballastless track of high-speed railway

Abstract

The invention discloses polymer cement mortar for a slab ballastless track of a high-speed railway. The polymer cement mortar a comprises a dry raw material and a liquid raw material, wherein the dry raw material comprises a binding material component, an elastic adjusting component, an expanding component, an internal curing component, an aggregate component and a coagulation adjusting component; the liquid raw material comprises a polymer emulsion, a water reducing agent, a defoaming agent, an air entraining agent and water; and the weight ratio of the dry raw material to the liquid raw material is 100:(15-25), and the dry raw material and the liquid raw material are uniformly mixed in a proportion to prepare the polymer cement mortar. The polymer cement mortar has the advantages of controllable coagulation time, high adhering strength, adjustable elastic modulus, good elasticity and toughness, high durability and the like, and is capable of replacing cement emulsified asphalt mortar to be applied to a packing material of the slab ballastless track or can be used as a quick repairing material of a filling layer of cement emulsified asphalt mortar.

Description

technical field [0001] The invention belongs to the field of rail transit engineering materials, and in particular relates to a polymer cement mortar used for filling layers of high-speed railway slab ballastless tracks. Background technique [0002] The slab ballastless track has become the main track structure type adopted by the 300 km / h high-speed railway in my country because of its high track smoothness, good stiffness uniformity, and strong stability. The slab ballastless track structure is mainly composed of prefabricated track slabs, filling layers , concrete base or hydraulic support layer, rail fasteners and other components. At present, the most widely used filling layer material is cement emulsified asphalt mortar. Among them, the cement emulsified asphalt mortar filling layer is the key structural part, and its main functions are filling, supporting, bearing, force transmission and providing proper elasticity and toughness. Ease of maintenance has a direct imp...

AI Technical Summary

Problems solved by technology

Cement-emulsified asphalt mortar mainly has the following problems: (1) Insufficient adhesion to concrete, which causes defects such as separation from the concrete of the track slab or base slab; (2) Insufficient durability, which causes the cement-emulsified asphalt mortar It is prone to peeling and other diseases; (3) Insufficient toughness, especially poor toughness at low temperature, resulting in cement emulsified asphalt mortar prone to cracks and other diseases

However, the current polymer cement mortar technology still has the following problems, which prevent it from being directly applied to the filling layer of high-speed railway ballastless track structure: (1) The cement emulsified asphalt mortar filling layer has strict requirements on material properties, especially in terms of elastic modulus On the one hand, the unit slab ballastless track requires an elastic modulus of 100-300MPa, and the longitudinal slab ballastless track requires an elastic modulus of 7000-10000MPa. The elastic modulus of the current polymer cement mortar is much higher than the filling material. As a result, its performance does not match the requirements of the filling layer, and it cannot be applied to the filling layer of ballastless track; (2) The cost is too high. In order to achieve better toughness, it is often necessary to add a large amount of polymer, which leads to its high cost and affects its performance. Popularization and application; (3) The shrinkage is relatively large. During the hardening process of the polymer mortar, the polymer demulsification and crosslinking process will produce a large shrinkage deformation; (4) When it is applied to the repair of the filling layer in the "skylight time", the early strength (2h) is insufficient to meet the traffic opening requirements after quick repair

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