Youjun Xie

CA Mortar Construction of the Trial Section of Wuhan-Guangzhou Railway Passenger Dedicated Line

A five-step controlling method in the construction of cement-emulsified asphalt mortar (CA mortar) at Wuhan-Guangzhou Railway Passenger Dedicated Line (WGRPDL) is presented. The gathered data of the temperature, the construction rate, the fluidity and the air content of CA mortar are also analyzed. Results showed that the controlling method was effective in the construction management and the temperature had serious impact on the construction rate. Results also showed that the fluidity and air content of CA mortar almost had the same relative standard deviation; moreover, the two factors seemed to have linear relationships.

Development of High-Performance Self-Compacting Concrete Applied as the Filling Layer of High-Speed Railway

AbstractThe filling layer of a China rail track system III (CRTS III) type ballastless track structure of a high-speed railway is a complicated structure typically constructed from self-compacting ...

Self-Compacting Concrete Reinforced by Waste Tyre Rubber Particle and Emulsified Asphalt

For the sake of developing new cementitious materials with high toughness and excellent workability, an extensive research programme was set up to investigate the properties of self-compacting concrete (SCC) with waste tyre rubber particles and emulsified asphalt in fresh state and hardened state. The effects of rubber particles and emulsified asphalt on strength, dynamic elastic modulus, stress-strain response and impact toughness of hardened SCC were analyzed in detail. Results indicate that rubber particle and emulsified asphalt remarkably influence mechanical properties of SCC. Incorporating rubber particles together with emulsified asphalt is conducive to improve self-compactability of fresh SCC. The strain capability and toughness of SCC can be greatly enhanced by addition of rubber particle and emulsified asphalt. A combination of rubber particles and emulsified asphalt is an effective way to prepare new SCC with excellent dynamic mechanical properties.

Ultraviolet irradiation of crumb rubber on mechanical performance and mechanism of rubberised asphalt

Nowadays, researchers have studied influences of ultraviolet on crumb rubber (CR)-modified asphalt (AR) and attempted to comprehensively understand mechanisms of ultraviolet on asphalt or AR entirety. In this article, ultraviolet influences on CR are discussed: mechanical performances of matrix asphalt, AR and strong ultraviolet-irradiated CR-modified asphalt are evaluated by dynamic mechanical analysis, bending beam rheometer and dynamic shearing rheometer (DSR); mechanisms of ultraviolet on CR, irradiated CR on asphalt and morphologies of CR are analysed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Results implied: (i) CR barely reacts with asphalt but irradiated CR reacts vigorously with asphalt by its new chemical bonds and growing internal crosslinkings; (ii) CR has a rough surface with porous shape and size but ultraviolet makes it become dense caused by oxidation; (iii) irradiated CR weakens low-temperature performances but enhances high-temperature anti-shearing performances of asphalt.

Effect of Strain Rate on Compressive Behavior and Modeling of Cement and Asphalt Mortar

AbstractThe compressive behavior of cement and asphalt mortar (CA mortar, including Types I and II CA mortar, namely CAI and CAII) under strain rates ranging from 10−5/s to 10−2/s was experimentall...