مقاله انگلیسی رایگان در مورد ویژگی دمپینگ ملات امولسیون آسفالت سیمان – الزویر 2018

Cement and asphalt materials are widely used for building construction, bridges, dams and road construction as the cementitious materials of the construction industry. Cement-based materials possess advantages of high strength and corrosion resistance, but they have large rigidity and poor non-deformability. Asphalt materials have strong resistance to deformation, excellent viscoelastic characteristics and damping performance. However, they are easy to bring about permanent deformation under loading actions [1,2]. Cement asphalt emulsion mortars are organic-inorganic composites, which consist of cement, asphalt emulsion, sand and admixtures. The interactions in cement asphalt emulsion mortars include the influence of cement on the process of emulsified asphalt demulsification and the influence of asphalt emulsion on the hydration process of cement [2,3]. The water coming from demulsification of asphalt emulsion can be used for cement hydration. The water can solve the contradiction between ‘‘water repellent” of emulsified asphalt demulsification and ‘‘water demand” of cement hydration. In contrast to cement-based materials and asphalt-based materials, cement asphalt emulsion mortars can not only combine the advantages of the two materials, but also can make up for the shortcomings of two types of materials [4]. Cement asphalt emulsion mortars are advanced engineering materials which getting more and more popular in high speed railway engineering projects [5]. There are two types of cement asphalt emulsion mortars, thyp I with more asphalt and less cement, as well as type II with more cement and less asphalt [6]. Fig. 1 shows the schematic diagram of the ballastless track structure of high-speed railway and position of cement asphalt emulsion mortar layer. The layer is the key structure of ballastless track of high-speed railway. Its main function is to fill, support tracks, bear force from tracks and trains and provide appropriate toughness. The performance of the layer can directly influence the durability of track structure and stability from the running train. The solidification hardening process of cement asphalt emulsion mortars is composed of cement hydration process and asphalt emulsion demulsification process. As an inorganic material, cement mainly displays the stiffness of its material in cement asphalt emulsion mortar. On the one hand, the cement is mixed with asphalt emulsion; and the water in the emulsified asphalt with cement is hydrated to provide strength for the mortars. Due to the viscoelastic energy of asphalt, the plasticity of cement asphalt emulsion mortars can be improved; and the anti-fracture properties of the mortars can be enhanced. After asphalt emulsion demulsification, the water in asphalt emulsion with cement granule is hydrated; and asphalt can permeate in the structure of the cement hydration products. The asphalt encircles with mesh structure packages on the surface of the cement hydration products. Thus the cement hydration can be influenced by asphalt [7].