scholarly journals Cement asphalt mortar for high-speed rail

2020 ◽  
Vol 65 (22) ◽  
pp. 2384-2394
Author(s):  
Dehua Deng ◽  
Qiang Yuan ◽  
Yong Wang
Keyword(s):  
High Speed ◽  
High Speed Rail ◽  
Cement Asphalt Mortar ◽  
Asphalt Mortar

scholarly journals Preliminary Study on Assessing Delaminated Cracks in Cement Asphalt Mortar Layer of High-Speed Rail Track Using Traditional and Normalized Impact–Echo Methods

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3022
Author(s):  
Ying-Tzu Ke ◽  
Chia-Chi Cheng ◽  
Yung-Chiang Lin ◽  
Yi-Qing Ni ◽  
Keng-Tsang Hsu ◽  
...  
Keyword(s):  
High Speed ◽  
Concrete Slab ◽  
Amplitude Spectrum ◽  
Peak Frequency ◽  
High Speed Rail ◽  
Impact Echo ◽  
Rail Track ◽  
Cement Asphalt Mortar ◽  
The Difference ◽  
Ca Mortar

The severe deterioration of a cement asphalt (CA) mortar layer may lead to the movement of the upper concrete slab and impair the safety of the speedy train. In this study, a test specimen simulating the structure of high-speed rail track slabs was embedded with delaminated cracks in various lateral sizes inside the CA mortar layer. Impact–echo tests (IE) were performed above the flawed and flawless locations. In present study, the IE method is chosen to assess defects in the CA mortar layer. Both traditional IE and normalized IE are used for data interpolation. The normalized IE are the simulated transfer function of the original IE response. The peak amplitudes in the normalized amplitude spectrum and the peak frequency in the traditional amplitude spectrum for the top concrete overlay were used to develop simple indicators for identifying the integrity of the CA mortar layer. The index was based on the difference of the experimental peak amplitude and frequency of the ones calculated from previously developed formulas for plates without substrates. As a result, the technique does not require an experimental baseline for the crack assessment. A field test and analysis procedure for evaluating high-speed rail slab systems are proposed.

scholarly journals Effect of Water and Emulsifier on the Mechanical Properties of Cement Asphalt Mortar

2019 ◽  
Vol 271 ◽  
pp. 03002
Author(s):  
Tri Ho Minh Le ◽  
Dae-Wook Park ◽  
Jung-Woo Seo
Keyword(s):  
High Speed ◽  
Mechanical Performance ◽  
Strength Development ◽  
Mechanical Degradation ◽  
Asphalt Emulsion ◽  
Term Operation ◽  
Cement Asphalt Mortar ◽  
Rail Structure ◽  
Asphalt Mortar ◽  
Mixing Water

The long-term operation of high-speed railway leads to remarkable issues in ballast mechanical degradation and track irregularity. Particularly, in mainline of rail structure, the required time for ballast layer maintenance is strictly short. To systematically cope with this problem, a comprehensive study was proposed to develop a new cement asphalt mortar (CAM) stabilized ballast method. This solution is expected to improve the ballast structural durability with fast application time. However, the engineer properties of CAM paste with different level of initial mixing water as well as the influencing mechanisms are not clearly understood. In this work, the effects of initial mixing water and emulsifier on the mechanical performance of CAM are mainly discussed. The characteristics of the mortar were determined by conducting the flowability test, mixing stability test, and unconfined compressive strength (UCS) test. The test results revealed that the initial mixing water plays an important role in both fresh and hardened stage of CAM, especially the demulsification process of asphalt emulsion. Meanwhile, the emulsifier imposed a critical effect on the strength development of CAM mixture.

scholarly journals Dynamic Characteristics of Rubber Powder Modified Cement Asphalt Mortar

2012 ◽  
Vol 5 ◽  
pp. 243-246 ◽  
Author(s):  
Yun Liang Li ◽  
Yang Jian Ou ◽  
Yi Qiu Tan ◽  
Ming Yu Lu
Keyword(s):  
High Speed ◽  
Damping Ratio ◽  
Beam Specimen ◽  
Rubber Powder ◽  
Cement Asphalt Mortar ◽  
Track System ◽  
Vibration Attenuation ◽  
Vibration Tests ◽  
The Impact ◽  
Asphalt Mortar

Cement asphalt mortar (CA) is mainly applied in track system of high-speed railways for vibration attenuation. The impact on dynamics performance of CA with the admixture of rubber powder was studied. The beam specimen made of CA was manufactured for analyzing its vibration frequency and damping characteristics by free attenuation vibration tests. Results showed that there was no big change for fundamental frequency after admixture of rubber powder. However, high order frequency and structural damping increased with the increase of admixture amount. Damping ratio of CA was increased by admixing rubber powder, which can be better for energy absorption and vibration attenuation.

Prepartion and Atypical Mechianical Performance of Epoxy Asphalt Cement Mortars Composite Material for High Speed Railway

2011 ◽  
Vol 90-93 ◽  
pp. 547-553 ◽  
Author(s):  
Xing Long Fang ◽  
Zhi Ming Chen ◽  
Zhen Jiao ◽  
Gang Hua Pan ◽  
Wen Ping Zhou ◽  
...  
Keyword(s):  
Compressive Strength ◽  
High Speed ◽  
Cement Mortar ◽  
Asphalt Emulsion ◽  
Asphalt Cement ◽  
Chemically Modified ◽  
Epoxy Asphalt ◽  
Cement Asphalt Mortar ◽  
Weather Resistance ◽  
Asphalt Mortar

Cement asphalt mortar is a key part of flexible adjusting layer in slab ballastless track structure. In this paper, new materials of epoxy asphalt cement mortar (EACM) was prepared with epoxy and chemically modified asphalt emulsionwhich showed excellent in terms of durability and weather resistance. This paper through changing the proportions of the eopxy-asphalt cement ration studies the relationship among fluidity, compressive strength, and elastic modulus of EACM and cement asphalt mortar (CAM) use chemical modification of asphalt emulsion and normal asphalt emulsion. The results showed that chemically modified epoxy asphalt emulsion cement mortar turned out to be relatively better in compressive strength, frost resistance and weather ability compared with CAM. The chemical reaction mechanism of epoxy asphalt emulsion were investigated by the means of environmental scanning electron microscope (ESEM) method.

scholarly journals Evaluation of the Effect of Fly Ash and Slag on the Properties of Cement Asphalt Mortar

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Tri H. M. Le ◽  
Dae-Wook Park ◽  
Jin-Yong Park ◽  
Tam M. Phan
Keyword(s):  
Fly Ash ◽  
High Speed ◽  
Laboratory Experiments ◽  
Cost Effective ◽  
Hydration Product ◽  
Strength Development ◽  
Test Results ◽  
Cement Asphalt Mortar ◽  
Asphalt Mortar ◽  
By Products

The application of cement asphalt mortar (CAM) in modern high-speed railways has been gaining attention due to its combined merits between asphalt and cement hydration product characteristics. To promote sustainable development, it is promising to utilize by-products in the making of new CAM instead of using only cement. In this research, the cement content was partly replaced by fly ash or ground-granulated blast furnace (GGBS) slag to achieve this objective. Then, laboratory experiments were conducted to determine the effect of these admixtures on the fresh and hardened characteristics of CAM. The test results revealed that the CAM mixture with slag received better fresh properties compared to the controlled mixture. However, the poor pozzolanic property of these by-product materials may lead to the low strength development. Meanwhile, although the mixture with fly ash suffered from slow strength establishment compared to the control mix at an early age, the strength of this condition increases dramatically after 28 days. Based on the findings, the application of appropriate fly ash content in the CAM mixture will not only provide ideal workable time and mixing stability but also ensure the required strength for the design target. This combination also serves as a cost-effective and environmental solution.

Performance of Cement Asphalt Mortar in Ballastless Slab Track over High-Speed Railway under Extreme Climate Conditions

2019 ◽  
Vol 19 (5) ◽  
pp. 04019037 ◽  
Author(s):  
Jinfeng Wang ◽  
Yubing Zhou ◽  
Tianmei Wu ◽  
Xi Wu
Keyword(s):  
High Speed ◽  
High Speed Railway ◽  
Climate Conditions ◽  
Slab Track ◽  
Extreme Climate ◽  
Cement Asphalt Mortar ◽  
Asphalt Mortar

scholarly journals Effect of cement asphalt mortar damage location on dynamic behavior of high-speed track

2018 ◽  
Vol 10 (4) ◽  
pp. 168781401877077 ◽  
Author(s):  
Jian Han ◽  
Guotang Zhao ◽  
Xinbiao Xiao ◽  
Xuesong Jin
Keyword(s):  
Dynamic Behavior ◽  
High Speed ◽  
Damage Location ◽  
Cement Asphalt Mortar ◽  
Asphalt Mortar

scholarly journals Temperature Sensitivity of Mechanical Properties of Cement Asphalt Mortar with Nanoparticles

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Xi Wu ◽  
Xing-Lang Fan ◽  
Jin-Feng Wang
Keyword(s):  
Compressive Strength ◽  
Temperature Sensitivity ◽  
High Speed ◽  
Cement Asphalt Mortar ◽  
Strength Based ◽  
Different Temperatures ◽  
Increasing Temperature ◽  
Positive Effect ◽  
Asphalt Mortar ◽  
Electronic Microscope

Cement asphalt mortar (CAM) in high-speed lines is subjected to varying environmental conditions, which lead to the deterioration of CAM. The nanoparticles of nano-SiO2 and nano-TiO2 are added to improve the performance of CAM, and the temperature sensitivity of CAM with nanoparticles is primarily studied in this paper. The flexural strength and compressive strength of CAM with and without nano-SiO2 and nano-TiO2 were measured and compared to study the effect of nanoparticles on the performance of CAM subjected to different temperatures. Temperature sensitivity factors of flexural and compressive strength based on Arrhenius model were proposed to evaluate the temperature dependence of CAM by nanoparticles. Furthermore, the microstructure of hardened CAM was studied using scan electronic microscope (SEM) to investigate the mechanism of temperature sensitivity of CAM with and without nanoparticles. The results indicated that the flexural and compressive strength of CAM with and without nanoparticles decreased with the increasing temperature; however, the decreasing rate of strength with temperature was different in CAM with and without nanoparticles. The reduction in the decreasing rate of strength was obtained by using nano-SiO2 rather than nano-TiO2 in CAM. Based on the SEM results, the free asphalt was seen to be greatly reduced in the CAM with nano-SiO2, suggesting a positive effect of nano-SiO2 on the mitigation of temperature sensitivity of CAM.

Dynamic Mechanical Analysis of CRTS II Cement Asphalt Mortar

2014 ◽  
Vol 584-586 ◽  
pp. 1646-1651
Author(s):  
Hua Yang Zhang ◽  
Long Hua Yuan ◽  
De Wei Ren
Keyword(s):  
Viscoelastic Properties ◽  
High Speed ◽  
Mechanical Analysis ◽  
Asphalt Emulsion ◽  
High Speed Railway ◽  
Burgers Model ◽  
Cement Asphalt Mortar ◽  
Different Temperatures ◽  
Ca Mortar ◽  
Asphalt Mortar

Cement asphalt mortar (CA mortar) is one of key structures of slab ballastless high-speed railway. Cement and asphalt emulsion are the main two components of CA mortar, making it possess the viscoelastic properties of viscoelastic materials, which is one of the infancy of the current study. In this paper, DMA method was adopted to investigate the viscoelastic properties of CRTS II CA mortar. Viscoelastic properties of CA mortar at different temperatures were investigated and were compared with the numerical simulation results of Burgers model. The results of the simulation fit in well with the data from the experimental-scale column, so we can study the dynamic modulus of CA mortar using the Burgers model in the temperature range of CA mortar.

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