Testing method of tensile adhesive strength of flexible polyurethane foam material for polyurethane solidification track bed

Abstract

The invention relates to a testing method of the tensile adhesive strength of a flexible polyurethane foam material for a polyurethane solidification track bed. The method mainly comprises the following steps: (1) erecting two cylinder railway ballast specimens oppositely and concentrically with an interval between the two specimens of 20mm, and sealing a cavity between the two specimens with kraft paper and an adhesive tape; (2) pouring the stirred double-component polyurethane slurry into the cavity, and dismounting the seal and cutting excessive foam bodies after the slurry reacts to expand in volume and is solidified, hardened and maintained for a period of time; (3) coating adhesives at two sides of the bonding specimens, and pasting positioning base plates to two sides of the specimens; (4) linking a tensile steel plate with pull rods to the positioning base plates by fastening bolts; (5) testing the bonding strength of the flexible polyurethane foam material and railway ballast stones along the tensile direction. According to the invention, the bonding strength of the flexible polyurethane material and the railway ballast stones is tested by adopting a sandwiched bonding specimen, and the testing method has the characteristics of reliable principle, convenience in installation and accuracy in measurement.

Description

technical field [0001] The invention relates to a test method for the tensile bonding strength of soft polyurethane foam and ballast used in high-speed (heavy-load) railway polyurethane solidified ballast, in particular to a method for testing polyurethane foam and ballast by using a sandwich bonded sample. Method for Tensile Bond Strength of Ballast Stone. Background technique [0002] The rapid development of my country's society and economy has put forward higher and higher requirements for railway transportation. Fast, safe and comfortable high-speed railways and heavy-duty railways with intensive transportation and large load capacity have become the main trend of my country's railway development. The operation and management of the track pose a severe test. The operation practice of ballasted track at home and abroad shows that with the increase of traffic volume, traffic density, axle load and driving speed, the deterioration rate of track geometry caused by ballast w...

AI Technical Summary

Problems solved by technology

In the technical system of polyurethane cured ballast, how to improve the integrity and stability of the consolidated body formed by soft polyurethane foam and ballast is the key to ensure the excellent performance of polyurethane cured ballast. In addition to the gaps, good bonding should be formed with the ballast, and the two form a solid whole, thereby ensuring that the ballast and the polyurethane foam material form a stable structure under the train load. It can be seen that the bonding performance is the key factor for evaluation. It is an important indicator of the performance of polyurethane foam materials in polyurethane cured ballast beds. However, the current test methods for the bonding performance between polymer materials and non-metallic materials are single-sided bonding test methods, that is, only one side of the tested material is connected to the substrate. Bonding, which is quite different from the current service situation in which the polyurethane foam material filled between the ballasts and the ballasts on both sides should be bonded, it is not suitable to evaluate the bonding performance of the two. Therefore, the present invention proposes a Ballast stone-soft polyurethane foam material-ballast stone sandwich composite structure, and a set of tensile bonding test device is designed to test the bonding performance of soft polyurethane foam material and ballast stone

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