The Method of Waterborne Epoxy Resin to Improve the Performance of Foamed Asphalt Cold Recycling Mixture

Abstract

The invention belongs to the technical field of construction of foamed asphalt cold recycled pavement, and in particular relates to a method for improving the performance of foamed asphalt cold recycled mixture with water-based epoxy resin. Adding into a mixing pot; step 2, adding mineral material, cement and foamed asphalt into the mixing pot, and stirring to obtain a foamed asphalt cold recycled mixture mixed with water-based epoxy resin. The invention prepares the foamed asphalt cold recycled mixture by using the water-based epoxy resin as a cold mixing external admixture, which can effectively improve the high temperature stability and water damage resistance of the foamed asphalt cold recycled mixture.

Description

technical field [0001] The invention belongs to the technical field of construction of foamed asphalt cold recycled pavement, and particularly relates to a method for improving the performance of foamed asphalt cold recycled mixture with water-based epoxy resin. Background technique [0002] Foamed asphalt is a special asphalt material that injects a certain amount of water into hot asphalt to expand its volume to form a large amount of asphalt foam and rupture in a very short time. When the foamed asphalt is in contact with the aggregate, the asphalt foam rapidly turns into "small particles" and spreads on the surface of the fine aggregate (especially the particle size is less than 0.075mm) to form a fine-grained joint filler with a large amount of asphalt. In fact, these fines can fill the voids of wet and cold coarse materials and play a mortar-like role to stabilize the mixture. [0003] The traditional indicators for evaluating the foaming performance of asphalt are ex...

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Problems solved by technology

[0005] The prior art includes the following problems: 1. The asphalt content in the foamed asphalt cold recycled mixture is small, and only part of the fine aggregate can be wrapped to form asphalt mortar, which is distributed in the mixture in the form of "spot welding". The recycled mixture is mainly composed of three parts: ①The skeleton structure formed by the accumulation of coarse aggregate particles; ②The asphalt mortar formed by foamed asphalt coated fine aggregate is distributed in dots; ③The fine aggregate not covered by asphalt It is in a loose state and filled between the skeleton aggregates (such as figure 1 As shown on the left), resulting in more voids in the mixture, loose and fine materials are easy to lose under the action of water, weakening the weak chemical bonds of active ingredients such as RAP, and reducing the tensile and water damage resistance of the mixture

[0006] 2. Asphalt is a thermoplastic material. The temperature of the regenerated layer is close to the softening point of the asphalt under high temperature conditions in summer. At this time, the viscosity of the asphalt decreases, resulting in a decrease in the cohesion of the foamed asphalt mortar and aggravated lubrication between the aggregates. This simple "spot welding" The asphalt mortar will flow rapidly, resulting in unstable rutting, which will reduce the high temperature stability of foamed asphalt cold recycled mixture

However, excessive cement content will seriously affect the low temperature and fatigue performance of the mixture, so the amount of cement is limited, and the mixture still has problems such as insufficient high temperature stability and water damage resistance.

[0008] 4. Adding external admixtures can improve the performance of foamed asphalt cold recycled mixture. At present, common external admixtures need to be melted at high temperature to form an organic whole with the mixture. If the external admixture is added in the form of modified matrix asphalt, after modification Asphalt has problems such as reduced foaming performance

In terms of improving the performance of foamed asphalt cold recycled mixture, there is still a lack of effective cold mixing admixtures and their addition process

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