Bakersfield asphalt emulsion8/26/2023 Therefore, CA mortar does not combine only the advantages of cement and emulsified asphalt materials but also improves the shortcomings of the two materials. The interaction between the constituent materials of CA mortar influences its properties the interactions between components of CA mortar include the impact of cement on the breakdown of emulsified asphalt and the effect of emulsified asphalt on the hydration process of cement. For instance, more asphalt (higher A/C) is required in CAM I when the railway structure requires more damping performance whereas more cement (lower A/C) is included in CAM II if the railway structure needs more strength compared to the damping performance. Moreover, with the properties of asphalt being more influenced by temperature as compared to cement, the dynamic mechanical response of CA mortar under varied service temperatures may differ. CA: cement emulsified asphalt.ĬAM I is mainly characterized by having high asphalt content, less cement, and a higher A/C ratio ranging between 0.6 to 1.2 contrarily, CAM II has a high cement content with less asphalt content and an A/C of about 0.2 to 0.6. CA mortar is produced by mixing its components using different mix proportions its properties are mainly controlled by the proportion of asphalt to cement (A/C ratio), which is the ratio of the content of asphalt to the content of cement by mass or by volume sometimes expressed as the ratio of asphalt emulsion to cement (AE/C).įigure 1. Structure of a slab ballastless track ( a) China Railway Track System (CRTS) I, ( b) CRTS II. This composite material possesses fascinating properties that are different from both concrete and asphalt material alone because it couples the strength of cement as well as the flexibility of asphalt material. In mainland China, the China Railway Track System (CRTS), categorized into CRTS I, CRTS II, and CRTS III, are the main types of ballastless track systems adopted in recent decades.ĬA mortar (sometimes abbreviated to CAM) is one of the major construction materials for slab ballastless track in high-speed railways it is an intermediate layer flung within the space between the track slab and the trackbed (as depicted in Figure 1) of CRTS I and CRTS II Cement and asphalt mortar is an organic–inorganic composite material primarily composed of asphalt emulsion, cement, sand, water, and other chemical admixtures. It is adopted all over the world due to the advantages it offers to the system over the ordinary ballasted track that includes reduced structural height, fewer maintenance requirements, durability, high lateral track resistance, which gives room for future speed increments, and no churning up of the ballast. Non-ballasted slab track is one of the foremost vital innovations created for high-speed railways. With the design of high-speed rail, there has been an increasing demand for a high-quality railway system that includes railway tracks, communication, and a signal system, etc.
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |