High weatherability composite modified asphalt for high-speed railway asphalt concrete waterproof sealing layer

Abstract

The invention discloses high weatherability composite modified asphalt for a high-speed railway asphalt concrete waterproof sealing layer. The high weatherability composite modified asphalt is prepared from the following components in percentage by weight: 70% to 79.8% of matrix asphalt, 15% to 20% of a modified composite, 5% to 10% of a component modifier, and 0.2 to 0.4% of a crosslinking agent,wherein the modified composite comprises a styrene-butadiene-styrol copolymer, that is, SBS copolymer, regenerated colloidal particles, and a mixture of an anti-aging agent and an interface enhancingagent. According to the high weatherability composite modified asphalt for the high-speed railway asphalt concrete waterproof sealing layer, (1) the composite modifier prepared by using the SBS copolymer, the regenerated colloidal particles, the anti-aging agent, and the interface enhancing agent can comprehensively improve stability, aging, and weatherability of the matrix asphalt, waste tires are fully utilized, and the cost is lowered, so that a modified asphalt cementing agent is more suitable for the high-speed railway waterproof sealing layer; and (2) according to the method, the composite modifiers are firstly prepared and then granulated, the interface enhancing agent is beneficial to the association between a modifier and the matrix asphalt, micro-nano dispersion of modifier molecules can be realized, the use amount of rubber is increased, and tire pollution is reduced.

Description

technical field [0001] The invention relates to a composite modified asphalt, in particular to a composite modified asphalt used for a high-weather-resistant high-speed railway asphalt concrete waterproof sealing layer, belonging to the field of asphalt modification and asphalt concrete waterproof sealing layer for new or repaired railway ballastless tracks. Background technique [0002] As the foundation of the high-speed railway track structure, the subgrade's strength, stiffness and stability are crucial to ensure the safe and smooth operation of the train. Studies have shown that the infiltration of water into the subgrade bed will not only reduce the strength of the subgrade soil, but also cause irregular cracks in the waterproof layer of the subgrade, which will damage the safety and stability of the subgrade. In order to ensure driving safety, it is necessary to spend a large amount of money every year to repair and maintain the roadbed. However, high-speed railways ...

AI Technical Summary

Problems solved by technology

However, previous studies mostly used raw rubber and SBS for modification, and more physical blending. However, SBS and rubber powder have poor compatibility with asphalt, and segregation is prone to occur.

The occurrence of this phenomenon is related to the three-dimensional network structure in raw rubber powder, which limits the micro-nano dispersion of rubber powder in the preparation process of modified asphalt, increases the viscosity of the modified asphalt system, and the surface activity of raw rubber powder is relatively low. Poor, unable to produce effective association with asphalt or SBS copolymer

According to the preparation method of a stretch-resistant and aging-resistant reclaimed rubber provided by patent CN108484970, it can be known that desulfurization of raw rubber powder can effectively break the three-dimensional network structure in the rubber powder and increase the active groups in the rubber particles, but it does not involve Modified asphalt field

In addition, the patent CN103819918 proposes a compound high-viscosity modified asphalt and its preparation method. It proposes to banbury SBS and desulfurized rubber particles to obtain a modified compound. By controlling the content of SBS and rubber powder, the density gap between the modifier and asphalt can be narrowed , high-viscosity modified asphalt with high storage stability can be obtained, but the proportion of SBS is too large, the cost of modified asphalt is high, and the effectiveness of the waterproof sealing layer for high weather resistance requirements has yet to be studied

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