Silicone caulking material for concrete expansion joints of ballastless tracks and preparation method thereof

Abstract

The invention relates to a silicone caulking material for concrete expansion joints of ballastless tracks and a preparation method thereof. The caulking material is composed of the following raw materials in parts by mass: 100 parts of alpha, omega-dihydroxy polydimethylsiloxane, 10-35 parts of a plasticizer, 70-120 parts of filler, 0.5-10 parts of a thixotropic agent, 6-12 parts of a crosslinking agent, 1-8 parts of a chain extender, 0.3-3 parts of an adhesion promoter, 0.1-2 parts of a catalyst, 0.005-0.5 part of a pigment, 0.5-5 parts of a storage stabilizer, and 1-3 parts of a deep curing agent. The silicone caulking material is prepared by using the preparation method disclosed by the invention. The silicone caulking material has the characteristics of good construction performance, high displacement capacity, good interface adhesion, excellent aging resistance, long storage life, good deep-layer curing performance, and the like, is suitable for being applied to concrete expansion joints of ballastless tracks of high-speed rails, expansion joints of airport pavements and cement concrete pavements, and the like, and also can be applied to the failure repair of existing expansion caulking materials.

Description

technical field [0001] The invention belongs to the field of building materials, and in particular relates to a silicone caulking material used for ballastless track concrete expansion joints and a preparation method thereof. Background technique [0002] With the rapid development of high-speed railway network construction, ballastless track structure has become the main track structure type used in my country's high-speed railway construction. The development of ballastless track technology is one of the important measures for my country's railways to rapidly improve the level of technical equipment and realize the leapfrog development of railways. In the ballastless track structure, in order to adapt to the deformation of the concrete structure at different temperatures, it is often necessary to set an expansion joint at a certain distance. At the same time, expansion joints are also reserved at the interface between the track structure and the foundation below the line,...

AI Technical Summary

Problems solved by technology

Asphalt caulking materials have the advantages of easy availability of raw materials and low cost, but there are many disadvantages: such as complex construction process, need to be heated before use; poor temperature adaptability, easy to become brittle at low temperature, easy to flow and extrude at high temperature ; Poor aging resistance, short service life, etc.

Most polyurethane caulking materials are two-component packaging, which needs to be measured and mixed on site. It is easy to cause the material to not cure or the performance after curing to meet the requirements due to measurement errors or uneven mixing; the temperature sensitivity is high, and the condition of low temperature (≤5°C) Under low temperature, the curing speed is slow, which has a great influence on the caulking effect

The failure of the caulking material will lead to the loss of the waterproof function of the joints of the ballastless track structure, and water will enter the interior of the ballastless track structure from the joints, which will affect the durability of the concrete structure of the ballastless track and the insulation performance of the ballastless track

Silicone caulking materials have the advantages of good construction and excellent durability, but silicone caulking materials have poor adhesion to concrete materials with porous interfaces, and the storage period is short; ballastless track concrete joints are generally deep, The deep curing performance of the caulking material inside the seam is poor, and the surface is easy to "wrinkle"

In the existing silicone caulking material technology, the materials that can achieve deep curing have a short storage period, and are generally prepared for immediate use. Materials with a long storage period do not have deep curing performance, and cannot achieve deep curing and long storage of silicone caulking materials. The dual needs of the cycle, and there is currently no high-performance silicone caulking material specifically for the concrete structure of the ballastless track of the high-speed railway

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